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Arbuscular mycorrhizal fungi (AMF) are drivers of plant communities as they influence plant competition by increasing plants’ root absorptive surface. As such, AMF could be an important tool for ecological restoration. However, a lack of research using AMF in sagebrush steppe communities implies a need for more assessments of its efficacy. Here, we assessed the ability of a commercial inoculum to colonize and influence growth of three native Artemisia spp. (sagebrush) shrubs and the exotic Taeniatherum caput-medusae (medusahead). We expected to increase colonization and biomass production with the addition of the inoculum. Before testing the inoculum, its viability was examined using Trifolium incarnatum (crimson clover) in autoclaved soil. Next, a factorial greenhouse experiment was conducted to evaluate the target species when grown in live or autoclaved field soil from a disturbed (early seral) site. Inoculation resulted in an average root colonization of 24.82% ± 4.86% for T. incarnatum but failed to colonize any of the sagebrush steppe species in autoclaved soil and had little to no influence on colonization in live soil. All sagebrush steppe species were colonized by AMF in live soil, and biomass production averaged 889 mg, 530 mg, 323 mg, and 1 852 mg, respectively; however, average biomass for all species was greater when grown in autoclaved soils (1 620 mg, 706 mg, 371 mg, and 3 902 mg, respectively). Our results reveal differential effects of a commercial AMF inoculum on root colonization of Artemisia spp. and T. incarnatum and highlight the need to assess the efficacy of AMF inoculum before field application.

In fire-prone environments, prescribed burning is important for achieving many public land management objectives including protecting communities and the environment from damaging bushfires. There is evidence that in some biomes, reducing the size of burnt patches and creating a fine-scale mosaic of vegetation at different times since last fire (seral stages) may benefit biodiversity. However, planning and implementing an ongoing burning program to achieve this is problematic. To advance an understanding of the factors affecting burn patch size and seral diversity metrics, a novel experimental management trial that aimed to create and quantify a fine-scale fire mosaic was implemented in a south-west Australian forest landscape. The 10-year trial demonstrated that the fire mosaic characteristics, including diversity of seral stages, burnt patch size, patch distribution and patch connectedness, can be managed to a large extent by ignition frequency, which affects landscape fuel flammability, and the timing of the introduction of fire with respect to weather conditions. In this trial, the frequent introduction of fire under low to moderate Forest Fire Danger Indices resulted in a landscape comprising a quantifiably higher diversity of seral stages and smaller burnt patches than adjacent areas treated by fuel reduction prescribed burns and by a high intensity bushfire.

Dasyurids are small mammals that can conserve energy and water by using shelters that insulate against extreme conditions, prevent predation, and facilitate torpor. To quantify the diurnal sheltering requirements of a poorly known, endangered dasyurid, the sandhill dunnart, Sminthopsis psammophila, we radiotracked 40 individuals in the Western Australian Great Victoria Desert between 2015 and 2019. We assessed the effect of habitat class (broad habitat features), plot-level (the area surrounding each shelter), and shelter characteristics (e.g., daily temperature ranges), on shelter selection and sheltering habitat preferences. Two hundred and eleven diurnal shelters (mean of 5 ± 3 shelters per individual) were located on 363 shelter days (the number of days each shelter was used), within mature vegetation (mean seral age of 32 ± 12 years postfire). Burrows were used on 77% of shelter days and were typically concealed under mature spinifex, Triodia spp., with stable temperature ranges and northern aspects facing the sun. While many burrows were reused (n = 40 across 175 shelter days), spinifex hummock shelters typically were used for one shelter day and were not insulative against extreme temperatures. However, shallow scrapes within Lepidobolus deserti hummock shelters had thermal advantages and log shelters retained heat and were selected on cooler days. Sminthopsis psammophila requires long-unburned sheltering habitat with mature vegetation. Summer fires in the Great Victoria Desert can be extensive and destroy large areas of land, rendering them a key threat to the species. We conclude that the survey and conservation of S. psammophila requires attention to long-unburned, dense lower stratum swale, sand plain, and dune slope habitats, and the tendency of S. psammophila to burrow allows the species to survive within the extreme conditions of its desert environment.

In order to stabilize the defining concepts of the higher rank syntaxonomic units such as class or order, the criteria of floristic content and unity of origin are enunciated. This is done with the aim of preventing the fragmentation of the large classes and the subsequent typological inflation. For orders, the criterion of specific floristic content is discussed, with orders that have been described to encompass seral secondary forests or the separation of forest vegetation from that which is dominated by shrubs rejected, due to their weak floristic characterization. These criteria have been applied to two forest vegetation classes: the European temperate (Querco-Fagetea) and the Mediterranean (Quercetea ilicis). For the first, it is argued in favor of maintaining a single class for all temperate deciduous forests in Europe instead of dividing them into four. Within this single class five orders are distinguished: Fagetalia, Quercetalia roboris, Quercetalia pubescenti-petraeae, Alno-Fraxinetalia and Populetalia albae, rejecting the orders that have been proposed for secondary forests because they have few characteristic taxa. For the sclerophyllous and macchia forests of Mediterranean Europe, the Quercetea ilicis class can be split into two or three geographical orders, rejecting the Pistacio-Rhamnetalia alaterni as a shrubby physiognomic unit. Taxonomic reference: Castroviejo S (coord. gen.) (1986–2012) Flora iberica 1–8, 10–15, 17–18, 21. Real Jardín Botánico, CSIC, Madrid, ES. Syntaxonomic reference: Mucina et al. (2016).

Background: Climate change is projected to alter the elevation and latitude of treeline globally. Seed germination and seedling survival are critical controls on treeline expansion. Neighbouring al...

Climate and landscape change are drivers of species range shifts and biodiversity loss; understanding how they facilitate and sustain invasions has been empirically challenging. Winter severity is decreasing with climate change and is a predicted mechanism of contemporary and future range shifts. For example, white-tailed deer (Odocoileus virginianus) expansion is a continental phenomenon across the Nearctic with ecological consequences for entire biotic communities. We capitalized on recent temporal variation in winter severity to examine spatial and temporal dynamics of invasive deer distribution in the Nearctic boreal forest. We hypothesized deer distribution would decrease in severe winters reflecting historical climate constraints, and remain more static in moderate winters reflecting recent climate. Further, we predicted that regardless of winter severity, deer distribution would persist and be best explained by early seral forage subsidies from extensive landscape change via resource extraction. We applied dynamic occupancy models in time, and species distribution models in space, to data from 62 camera traps sampled over 3 years in northeastern Alberta, Canada. Deer distribution shrank more markedly in severe winters but rebounded each spring regardless of winter severity. Deer distribution was best explained by anthropogenic landscape features assumed to provide early seral vegetation subsidy, accounting for natural landcover. We conclude that deer dynamics in the northern boreal forest are influenced both by landscape change across space and winter severity through time, the latter expected to further decrease with climate change. We contend that the combined influence of these two drivers is likely pervasive for many species, with changing resources offsetting or augmenting physiological limitations.

Background Schima genus of Theaceae is confined to subtropics and tropics of South, East and Southeast Asia. Thirteen species of Schima are distributed in subtropical China. Many of them appear as dominant canopy species in the subtropical forests. To date, Schima species richness distribution patterns of China have remained unknown. Meanwhile, there has been a longtime debate as to whether forests dominated by Schima species are early or late successional forests. We aim to clarify Schima species richness patterns and these species’ roles in the forest succession and regeneration dynamics of the subtropical ecosystem in Yunnan Province, China. Method We mapped Schima species richness distribution patterns in China. Based on 71 vegetation plots, we analyzed forest characteristics, population structure, and regeneration dynamics of Schima species in Yunnan. Results Yunnan was found to harbor the greatest richness and the highest rarity-weighted richness of Schima species in the subtropical regions of China. We classified five primary and six secondary forest types containing Schima species as one of dominants. Yunnan had the high floristic diversity and varying stand structure of forests containing Schima species. The Schima species studied generally had a sporadic regeneration type and a long life-span. Four species (Schima argentea, Schima villosa, Schima sinensis, Schima sericans) were shade-intolerant. But three species (Schima noronhae, Schima khasiana and Schima wallichii) were considered as bi-modal type species having shade-intolerant and shade-tolerant traits. Schima noronhae was seen to be a top dominant in late successional forests, while S. wallichii was found as a top-dominant in early or middle or late successional forests. S. khasiana, Schima villosa, Schima sinensis usually appeared as a top dominant in early or middle successional secondary forests, though they also presented as a second dominant in late-successional forests. Schima argentea and Schima sericans dominated only in the early or middle/seral successional forests. Schima species’ regeneration establishment depended mainly on forest canopy gap formation through moderate human and natural disturbances. Conclusions Yunnan has high species richness and rarity-weighted richness of Schima. Both moderate human and natural disturbances have provided regeneration niches for Schima species. Some of the Schima species studied as a second dominant (rare as the top-dominant) present in the late-successional forests. Some of them are more often as the top-dominant in early or middle successional forests, where as time goes by the dominance of Schima species would be replaced by their associated dominant taxa such as Castanopsis species.

Glaciers are receding at unprecedented rates in the alpine tropics, opening-up new areas for ecosystem assembly. However, little is known about the patterns/mechanisms of primary succession during the last stages of glacier retreat in tropical mountains. Our aim was to analyze soil development and vegetation assembly during primary succession, and the role of changing adaptive strategies and facilitative interactions on these processes at the forefront of the last Venezuelan glacier (Humboldt Peak, 4,940 m asl). We established a chronosequence of four sites where the glacier retreated between 1910 and 2009. We compared soil organic matter (SOM), nutrients and temperatures inside vs. outside biological soil crusts (BSCs) at each site, estimated the cover of lichen, bryophyte and vascular plant species present, and analyzed changes in their growth-form abundance and species/functional turnover. We also evaluated local spatial associations between lichens/bryophytes and the dominant ruderal vascular plant (the grass Poa petrosa). We found a progressive increase in SOM during the first century of succession, while BSCs only had a positive buffering effect on superficial soil temperatures. Early seral stages were dominated by lichens and bryophytes, while vascular plant cover remained low during the first six decades, and was almost exclusively represented by wind dispersed/pollinated grasses. There was a general increase in species richness along the chronosequence, but it declined in late succession for lichens. Lichen and bryophyte communities exhibited a higher species turnover than vascular plants, resulting in the loss of some pioneer specialists as succession progressed. Lichen and bryophyte species were positively associated with safe-sites for the colonization of the dominant ruderal grass, suggesting a possible facilitation effect. Our results indicate that lichens and bryophytes play a key role as pioneers in these high tropical alpine environments. The limited initial colonization of vascular plants and the progressive accumulation of species and growth-forms (i.e., direct succession) could be linked to a combination of severe environmental filtering during early seral stages and limitations for zoochoric seed dispersal and entomophilic/ornithophilic pollination. This could potentially result in a slow successional response of these ecosystems to accelerated glacier loss and climate change.

Although the identification of plant communities is the basic language of communication, studies that focus on the classification of vegetation in successional series are rather rare, mainly because it is difficult to identify different types of vegetation. Thanks to formalized algorithms of machine learning, we were able to assign some of vegetation plots stored in a Database of Successional Series (DaSS) to alliances in the vegetation classification system. Of the samples in DaSS 67.4% were classified into 96 vegetation alliances. Classification of the seral stages was then used to predict optima and intervals of occurrence of 33 main types of vegetation in the first 70 years from the onset of succession. In accordance with general expectations, main types of vegetation were arranged at the time-scale from ruderal and segetal vegetation, across grasslands to shrubby and forest vegetation. Successional optima of particular units of vegetation can be used to roughly predict the successional changes at human-disturbed sites in central Europe.

We compared early seral development between stands subject to single and repeated high-severity wildfire in low-elevation, mixed conifer – hardwood forests in the Klamath Mountains, California, USA. We used a before–after, control–impact (BACI) approach to assess changes in the density of conifer regeneration and the cover of multiple components of vegetation structure (conifers, hardwoods, shrubs, forbs, and graminoids) and compare pathways of seral development between plots that burned once and plots that burned twice. Fifty-three field plots were established 6 years following a high-severity fire in 2004. Nineteen of these plots experienced a second high-severity wildfire 11 years later (2015), and all plots were remeasured in 2016–2017. Conifer regeneration was abundant following the first fire but was greatly reduced by the second fire. Plots that did not reburn increased in conifer, hardwood, and shrub cover, whereas plots that reburned increased in forb cover and decreased in shrub, hardwood, and conifer cover. Despite conifer loss, we found little evidence of shifts to nonforested states following repeated fire due to resilience of resprouting hardwoods. Our results indicate that repeated high-severity fire has the potential to protract early seral development and catalyze transitions from mixed conifer – hardwood forest to hardwood-dominated early seral conditions.

Mountain forest ecosystems are vital for maintaining nature’s contribution to people and human well-being. Over the last few decades’ threat to biodiversity due to human induced degradation have had a major impact on moist temperate mixed broad leaved forests of Central Himalaya. Study was carried out and compared to understand the forest structure and regeneration in a protected forest (Alnus nepalensis stand), community forest (Lyonia-Rhododendron stand) and reserve forest (Quercus floribunda stand) in Upper Kedarnath valley of Uttarakhand. A total of 34 species of trees, 28 shrub species, and 45 species of herbs were reported from these forest stands. Total tree density was higher at Q. floribunda stand and lower in A. nepalensis stand. Total tree basal area varied from 59.12 (in A. nepalensis) to 101.28 m2 ha−1 (Q. floribunda stand). The sapling, seedling, shrubs and herbs density was higher in Lyonia-Rhododendron stand than other two stands. Quercus leucotrichophora, Rhododendron arboreum, Lyonia ovalifolia, Neolitsea pallens were dominant tree species in lower girth classes in Lyonia-Rhododendron stand and A. nepalensis stand whereas, Cinnamomum tamala, Ilex dipyrena in higher girth classes were dominant in Q. floribunda stand. Cumulative Disturbance Index and Ramakrishnan Index of Stand Quality was analyzed to understand the forest stand quality. Our study provides insights to changing regeneration patterns and also stand quality of forest stands in Central Himalaya. The dominance of seral species and pioneers than climatic climax species is indication that forests are struggling from continuous encroachment that might jeopardize flow of ecosystem services from forests. There is vital need to take stock of scattered but vital scientific findings to develop scientific and appropriate planning and management of broad leaved forests in Central Himalaya.

Linear disturbances impact ecosystems and species worldwide. These impacts are perhaps most profound in forest ecosystems like the Canadian boreal forest which has been fragmented by an extensive network of seismic lines which affect a number of boreal species. Of particular concern are the impacts of seismic lines on boreal and mountain woodland caribou (Rangifer tarandus caribou), which are declining across Canada primarily because of an increase in anthropogenic habitat disturbance including seismic lines, within their ranges. Restoring seismic lines is a focus of conservation efforts for caribou, however their extensive footprint implies that restoration efforts will need to be prioritized to target the ultimate (habitat disturbance, early seral stage vegetation), and proximate (wolf predation) causes of caribou declines. To help inform restoration efforts we used field data collected in 2014 and 2015 from 291 seismic lines in west-central and north-western Alberta, Canada, and GIS-derived and remote sensing (LiDAR) data to model and map vegetation recovery (growth, structure, and composition) on seismic lines and along seismic line edges. Although we found differences among regions and taxa, generally we found that wet seismic lines and seismic lines adjacent to open forest stands were more likely to have more early seral stage vegetation that is attractive wildlife forage. We also found that in west-central Alberta, wet seismic lines had less vegetation growth and cover, while in north-western Alberta, wet seismic lines were more likely to have more vegetation cover, but there was no relationship between vegetation growth on seismic lines and seismic line wetness. Using field data we predicted that vegetation on seismic lines within our study area had grown between 1 and 2 m between 2007 and 2015; however as our models of vegetation growth did not validate well other techniques (e.g. UAVs) and studies focused at smaller scales are likely to provide accurate data on current vegetation height and cover on seismic lines. Our results combined with results from previous research provide further evidence that seismic lines, particularly wet seismic lines, need active restoration to re-establish natural vegetation trajectories. Overall, targeting seismic line restoration treatments to change vegetation composition, as well as structure and height, will likely help to restore ecosystem function for caribou and other boreal species.

Suites of fungal adaptation to nutrient acquisition and allocation of vegetations are observed along forest succession gradients. However, the mechanisms behind seral shifts in plant-associated fungi need to be uncovered. To bridge this knowledge gap, the current study investigated the litter and soil chemical variables as well as the fungal community using high-throughput Illumina MiSeq sequencing along a 30a-100a succession gradient of a subtropical forest ecosystem in Xishuangbanna, southwestern China. Litter nitrogen (N) content changed consistently with fungal alpha-diversity and the relative abundances of functional guilds, such as saprotrophs and arbuscular mycorrhizal (AM) fungi. However, this trend was opposite to that observed for ectomycorrhizal (EcM) fungi and litter carbon (C) content. The total and water-soluble C and N contents as well as the C/N ratios in soil decreased with stand age, while the relative abundances of Rozellomycota, Chytridiomycota and lichens as well as the microbial C and N use efficiencies exhibited increasing trends across succession stages. Multivariate analysis and multiple linear regression showed that the seral shifts in fungal diversity and composition were closely related to the C:N stoichiometry of soil and litter. Specifically, the litter C content either negatively explained the alpha-diversity and saprotroph abundance or positively explained the abundance of EcM fungi. In contrast, the litter N content presented opposite trends. Further, the variances in the abundances of Rozellomycota and AM fungi were negatively explained by water-soluble C content but positively explained by water-soluble N content in the soil. These findings confirm that the replenishment and reduction of available nutrients are determined by plant-fungus interactions via the C:N stoichiometry of litter and soil along the forest chronosequence.

The practice of aggregated retention is becoming increasingly common in forests managed for multiple objectives (e.g., timber production and maintenance of biodiversity). Undisturbed patches of forest (aggregates) can serve as refugia for disturbance-sensitive species and as dispersal sources for recolonization of adjacent harvested areas. However, few studies have characterized the contributions of aggregates to the natural recruitment or height growth of regenerating trees. In this study, we modeled the density and height of early- and late-seral conifers, including post-harvest recruitment and advanced regeneration (survivors), two decades after aggregated-retention harvest at four sites in the Cascade Mountains of Oregon and Washington. Predictors included distance from edge (0–70 m), edge type (1-ha aggregate vs. intact forest/harvest-unit boundary), and edge exposure (a proxy for heat/moisture stress). For both early- and late-seral species, we observed similar declines in density with distance from aggregate and intact-forest edges. Trends in height growth showed greater variation among sites and seral groups. Height tended to increase with distance from edge, peaking sooner for late-seral advanced regeneration than for early-seral recruitment. In contrast, heights of late-seral recruitment were distinctly shorter and unaffected by distance from edge. Edge exposure did not have a consistent effect on recruitment density or height growth of either seral group. Our results indicate that 1-ha aggregates are functionally equivalent to larger blocks of intact forests in their influences on conifer recruitment and growth. By distributing aggregates across harvest units, managers can accelerate rates of recruitment and promote heterogeneity in the density and height structure of the regenerating forest. Additional research is needed on the sensitivity of regeneration processes to aggregate size, shape, and spatial distribution.

The relative contribution of private and public forest to the conservation of species in mixed-ownership landscapes has often been contentious because management goals vary among owners. This tension can be exacerbated by a lack of understanding about how wildlife use habitats managed by different landowners and the relative value of habitats in having different structures, configurations, and management histories. To address this knowledge gap and enhance science-based conservation planning among different ownerships, we analyzed habitat selection by 53 GPS-tagged California spotted owls across multiple temporal scales within mixed-ownership landscapes in the Sierra Nevada. At a fine temporal scale, step-selection function analysis of hourly locations collected by GPS tags suggested that foraging spotted owls selected closed-canopy, larger-tree forest (Quadratic Mean Diameter [QMD] ≥ 33 cm, canopy cover ≥ 60%). Point selection function (PSF) analysis based on single nightly locations suggested that spotted owls selected a broader range of forest conditions including selection of forests having intermediate sized trees and intermediate canopy cover (QMD 28–33 cm, canopy cover ≥ 50%), and the strength of selection for these forest conditions increased in the less frequently used areas of home ranges. The PSF also suggested that spotted owls selected areas with relatively high cover type heterogeneity that included a mix of seral stages, except in the core of their home range where they selected relatively spatially homogenous forests characterized by large trees and closed canopy. Spotted owl home ranges increased in size with increasing elevation and cover type heterogeneity, and decreased in size with forest characterized by intermediate-sized trees. Collectively, these results indicate that landscapes having forest patches characterized by either intermediate or large-sized trees, both with high canopy cover, likely constitute the important foraging habitat for California spotted owls in Sierra Nevada mixed conifer forests. However, selection for any one particular cover type was not sufficiently strong for us to infer selection of individual landownership types, in spite of differences in forest conditions among ownerships. Collectively, our findings suggest that privately-owned lands used in our study may harbor more suitable spotted owl foraging habitat than previously recognized. Finally, given the importance of understanding the relationship between landowner management priorities and the resultant pattern of vegetation on lands with different ownerships, the development of forest management strategies relevant for broad-scale conservation of the Sierra Nevada forest will benefit from effective collaboration between forest managers, landowners, and research organizations.

Mowing is a common management technique employed in Europe and North America to manage seral wetland plant communities to: (a) prevent development to late succession, (b) minimise internal eutrophication and (c) conserve biodiversity. However, little is known about the effect mowing has on water quality, and the duration of any effects. Therefore, mowing treatments were applied in two abandoned fen plant communities: a Schoenus nigricans-Juncus subnodulosus (SN) community (hand-cutting) and a Cladio-Molinietum (CM) community (machine mowing). Mowing took place once in each community across three sites in North Wales, U.K. Effects on water chemistry were followed for two years post mowing.

Mountain ecosystems contain strong elevational gradients in climate and vegetation that shape species distributions and the structure of animal communities. Nevertheless, studies of habitat selection for individual species rarely account for such gradients that often result in species being managed uniformly across their range, which may not improve conservation as intended. Therefore, we characterized variation in nocturnal habitat selection by 18 GPS‐tagged California spotted owls (Strix occidentalis occidentalis) along a 1400‐m elevational gradient in the Sierra Nevada, California. We characterized three‐dimensional forest structure with light detection and ranging data that we used in mixed‐effects resource‐ and step‐selection analyses of owl habitat selection. At lower elevations, owls selected stands with shorter trees, sites closer to hard edges between tall forests and open areas, sites with less diversity in forest seral types and sites with more ridge and southwest aspects. In contrast, owls at higher elevations selected the opposite. Within public forests that had taller trees and within their home range core (45% kernel density estimate of GPS points) areas, owls selected forests with less and more canopy cover at low and high elevations, respectively. Outside of their core areas, owls selected areas with fewer and more tall trees at low and high elevations, respectively. These findings may be explained by elevational gradients in prey distribution and variation in owl diet because owls consume more woodrats (Neotoma spp; earlier seral species) at lower elevations and more flying squirrels (Glaucomys sabrinus; older forest species) at higher elevations. Thus, at low elevations and in areas unlikely to support nesting, spotted owls could benefit from management that promotes woodrat habitat by encouraging oak regeneration and creating small brushy openings within forests with shorter (younger) trees. Conversely, at higher elevations, (1) enhancing flying squirrel habitat by promoting large trees and denser canopy on mesic sites and (2) managing for greater cover type diversity on southwest‐facing slopes and ridgetops is more likely to improve foraging habitat quality for spotted owls. The patterns of owl selection over elevational gradients has not been explicitly considered in most habitat management plans but clearly would improve management throughout mountain ecosystems.

Background Decades of fire exclusion in the southern Appalachian Mountains, USA, has led to changing forest structure and species composition over time. Forest managers and scientists recognize this and are implementing silvicultural treatments to restore forest communities. In this study, conducted at the southern Appalachian Fire and Fire Surrogate Study site in Green River Game Land, North Carolina, USA, we assessed the effects of four fuel-reduction methods (burned four times, B; mechanical treatment two times, M; mechanical treatment two times plus burned four times, MB; and control, C) on the changes in understory community from pre-treatment to post-treatment years (2001 to 2016). We used non-metric multidimensional scaling (NMDS) to determine overall understory community heterogeneity, agglomerative hierarchical cluster analyses (AHCA) to determine finer-scale changes in understory community structure, and indicator species analyses (ISA) to identify the species that were associated with the different fuel reduction treatments over time. Results The NMDS ordination showed little separation between treatment polygons. The AHCA resulted in two main categories of understory species responses based on how treatment plots clustered together: (1) species apparently unaffected by the treatments (i.e., no treatment pattern present within cluster); and (2) species that responded to B, M, or MB treatments (i.e., pattern of treatment plots present within cluster). Nearly half (49.2%) of tree-species plots clustered based on treatments; 60% of shrub-species plots clustered based on treatments; and 64% of herbaceous-species plots clustered based on treatments. Many plots clustered similarly in response to fire-related treatments (B and MB). The ISA identified 11 total tree species: three in B, one in M, and seven in MB; six total shrub species: two in M, and four in MB, and 17 total herbaceous species or genera: one in C, and 16 in MB. Conclusion Fire and fire surrogate treatments did not dramatically shift understory composition after 15 years. However, certain ruderal and early seral species responded positively to MB, which was the most intensive treatment. Modest understory community changes were also observed in B, suggestive of early signs of shifting composition toward a more open forest community after four burns.

Large, high-severity wildfires, or “megafires,” occur periodically in arid Australian spinifex (Triodia spp.) grasslands after high rainfall periods that trigger fuel accumulation. Proponents of the patch-burn mosaic (PBM) hypothesis suggest that these fires are unprecedented in the modern era and were formerly constrained by Aboriginal patch burning that kept landscape fuel levels low. This assumption deserves scrutiny, as evidence from fire-prone systems globally indicates that weather factors are the primary determinant behind megafire incidence, and that fuel management does not mitigate such fires during periods of climatic extreme. We reviewed explorer’s diaries, anthropologist’s reports, and remotely sensed data from the Australian Western Desert for evidence of large rainfall-linked fires during the pre-contact period when traditional Aboriginal patch burning was still being practiced. We used only observations that contained empiric estimates of fire sizes. Concurrently, we employed remote rainfall data and the Oceanic Niño Index to relate fire size to likely seasonal conditions at the time the observations were made. Numerous records were found of small fires during periods of average and below-average rainfall conditions, but no evidence of large-scale fires during these times. By contrast, there was strong evidence of large-scale wildfires during a high-rainfall period in the early 1870s, some of which are estimated to have burnt areas up to 700,000 ha. Our literature review also identified several Western Desert Aboriginal mythologies that refer to large-scale conflagrations. As oral traditions sometimes corroborate historic events, these myths may add further evidence that large fires are an inherent feature of spinifex grassland fire regimes. Overall, the results suggest that, contrary to predictions of the PBM hypothesis, traditional Aboriginal burning did not modulate spinifex fire size during periods of extreme-high arid zone rainfall. The mechanism behind this is that plant assemblages in seral spinifex vegetation comprise highly flammable non-spinifex tussock grasses that rapidly accumulate high fuel loads under favorable precipitation conditions. Our finding that fuel management does not prevent megafires under extreme conditions in arid Australia has parallels with the primacy of climatic factors as drivers of megafires in the forests of temperate Australia.

In rehabilitating degraded areas in Manolo Fortich, Bukidnon, Philippines, the assessment and overall contribution of the leguminous tree species, Calliandra calothyrsus, were observed using the Landscape Function Analysis (LFA). For temporal effects, different seral stages of C. calothyrsus, found all over the rehabilitation areas, were tested for soil stability, infiltration, and nutrient cycling. For baseline, a field of Imperata cylindrica (cogon grass) was used, whereas a secondary forest served as reference point for study objective. After simulation of 3 years, the LFA results showed that in all indices and in all seral stages, the sites planted with C. calothyrsus improved when compared with I. cylindrica and showed a steady increase compared with the secondary forest. The results implied that the preplanting of C. calothyrsus contributes positively in ensuring successful rehabilitation of degraded areas. The concomitant benefits include water quantity/quality, microclimate amelioration, and soil erosion protection among others. These benefits directly affect the surrounding local communities and indirectly the lowlands by mitigating the chances of floods. Planting of C. calothyrsus is highly recommended after these results, but further studies are needed with different environmental variables to establish the positive effects across diverse landscapes in the Philippines.

Background: Landslides can cause substantial environmental, social and economic impacts. Under future climate scenarios the frequency of landslide-triggering events is likely to increase. Land managers, therefore, urgently require reliable high-resolution landslide susceptibility models to inform effective landslide risk assessment and management. Methods: In this study, gridded rainfall, topography, lithology and land cover surfaces were used to develop a high-resolution (10 m x 10 m) spatial model of landslides that occurred in Tasman, New Zealand during a period when ex-tropical Cyclone Gita brought heavy rain to the region. We separately modelled landslides in the same dataset as a function of the erosion susceptibility classification (ESC) data layer used to determine the level of control applied to forestry activities under the National Environmental Standards for Plantation Forestry (NES-PF). Models were fit using boosted regression trees. Results: Our preferred model had excellent predictive power (AUROC = 0.93) and included the parameters: aspect, elevation, mid-slope position, land cover, rainfall, slope, and a descriptive seven-class topographical index. Land cover, elevation, rainfall, slope and aspect were the strongest predictors of landslides with the land cover classes ‘seral native vegetation’ and clear-felled plantation forest’ predicting higher probabilities of landslides and tall native forest and closed canopy plantation forest predicting lower probabilities of landslides. The ESC was a poor predictor of landslides in the study area (AUROC = 0.65). Conclusions: Our study shows that accurate, high-resolution landslide probability surfaces can be developed from landslide distribution, land cover, topographical and rainfall data. We also show that landslide occurrence in the Tasman region could be substantially reduced by increasing the extent of permanent forest cover and by limiting clear-fell harvest of plantation forests on landslide-prone slopes. The ESC framework that underpins the NES-PF was a poor predictor of landslides and, therefore, an unreliable basis for regulating forestry activities in the Tasman, New Zealand.

QUESTIONS: (1) How much do abiotic site factors and land‐cover categories influence the course of succession across successional series at a country scale? (2) Are there any differences in the abiotic site factors and land‐cover categories which are responsible for driving primary and secondary seres? (3) Which of the factors influence species richness and participation of target species? LOCATION: Various disturbed sites in the Czech Republic, Central Europe. METHODS: The Database of Successional Series (DaSS) was compiled of 21 different types of succession, comprising 2,846 phytosociological releves. The stages ranged from 1 to >150 years in age. Abiotic site factors included macroclimate characteristics and substrate; landscape factors comprised various land‐cover categories in a radius of 1 km around each sampled site. Principal Coordinate Analysis of Neighbour Matrices (PCNM) was performed to quantify the effect of abiotic site factors and landscape factors on seral vegetation, also regarding the primary or secondary status of succession. The relationships between number of species, number and proportion of target species and abiotic site and landscape factors were further assessed using generalised linear model analysis. RESULTS: All considered abiotic and landscape factors were found to have significant effects on the course of succession. The effects of abiotic site factors appeared to be more important than those of the surrounding landscape structure. Species richness was higher on basic substrates. The proportion of target species increased with increasing woodland area in the surrounding and with a wetter and colder climate, and decreased with urbanisation rate of the landscape. CONCLUSION: Not only local but landscape factors, such as climate and land cover, should be considered in any study of succession, as they substantially influence the general successional pattern. Quantification of the role of these environmental factors may help to decide where a spontaneous restoration is a viable option for the restoration of disturbed sites. The primary or secondary status of succession is less relevant than has usually been supposed.

Variable retention (VR) has been adopted globally as an alternative to more intensive forms of regeneration harvest. By retaining live trees within harvest units, VR seeks balance among the commodity, ecological, and aesthetic values of managed forests. Achieving these multiple, often competing objectives requires an understanding of how level and spatial pattern of retention shape the abundance, growth, and mortality of regenerating and retained trees. Using long-term (18-19 yr) data from a regional-scale VR experiment, we explore the individual and interactive effects of retention level (15% vs. 40% of initial basal area) and pattern (dispersed vs. aggregated) on the post-harvest dynamics of forests of differing structure and seral composition. Level and pattern of retention imposed trade-offs for the density and growth of regenerating trees (≥0.1 m tall

Fire exclusion has dramatically altered historically fire adapted forests across western North America. In response, forest managers reduce forest fuels with mechanical thinning and/or prescribed burning to alter fire behavior, with additional objectives of restoring forest composition, structure, and ecosystem processes. There has been extensive research on the effects of fuel reduction and restoration treatments on trees, fuels, regeneration, and fire behavior, but less is known about how these treatments influence understory vegetation, which contains the majority of vascular plant diversity in many dry conifer forests. Of particular interest is how understory vegetation may respond to the season and interval of prescribed burning. The season and interval of prescribed burning is often determined by operational constraints rather than historical fire regimes, potentially resulting in fire conditions and burn intervals to which native plants are poorly adapted. In this study, we examined how understory vegetation has responded to season and interval of prescribed burning in ponderosa pine (Pinus ponderosa) forests in the Blue Mountains of northeastern Oregon, USA. Using over a decade (2002&ndash, 2015) of understory vegetation data collected in stands with different intervals (5 versus 15 year) and seasons (spring versus fall) of prescribed burning, we quantified how season and interval of prescribed burning has influenced understory vegetation compositional trajectories and indicator species over time. Season of prescribed burning resulted in different understory communities and distinct trajectories of understory composition over time, but interval of burning did not. Indicator species analysis suggests fall burning is facilitating early seral species, with native annual forbs displaying ephemeral responses to frequent burning, while invasive cheatgrass (Bromus tectorum) increased in abundance and frequency across all treatments over time. These findings indicate that understory vegetation in these ecosystems are sensitive to seasonality of burning, but the responses are subtle. Our findings suggest season and interval of prescribed burning used in this study do not result in large changes in understory vegetation community composition, a key consideration as land managers increase the pace and scale of prescribed fire in these forests.

Background Most of the Pinus densiflora forests, occupying the largest area, have been restored in South Korea since the 1970s. As young pioneer forests, the succession process is under way. Since the forests are distributed nationwide and are vulnerable to disturbances, the process may differ depending on the geography and/or site conditions. Therefore, we reviewed the direction, the seral communities, and the late-successional species of progressive and disturbance-driven succession nationwide in the cool-temperate zone through meta-analysis and empirical observations. Main text As a result of a meta-analysis of the direct succession and vertical structure, we found that the P. densiflora forest is in a directionally progressive succession, changing to the broadleaved forest after forming a mixed forest with its overwhelming successor, Quercus species (particularly Q. mongolica and Q. serrata). In dry stands in a relative sense, the Quercus species was favored occupying over 80% of the abundance of the succeeding species. Therefore, in dry stands, it is presumed that Quercus-dominated stage would last for a long time due to the current dominance and long life span, and eventually, it settles as Quercus-broadleaved forest with a site change. Contrary to this, it is presumed that in mesic stands where Quercus species do not occur or have low abundance, the late-successional broadleaved species settle early to form a co-dominant forest with multiple species. Due to geographical limits, the species composition of the two late-successional forests is different. Disturbances such as insect pests and fire retrogressed vulnerable P. densiflora forest for a while. However, it was mostly restored to the Quercus forest and is expected to be incorporated in the pathway of the dry stand. Conclusions We revealed the succession process of P. densiflora forests according to geography and moisture and found that stand moisture had a decisive effect on the species and abundance of the successor. Although the P. densiflora forest is undergoing structural changes, the forest is still young; so within a few decades, physiognomy is not likely to change. Therefore, the decrease in the forest area may be due to other causes such as disturbances and forest conversion rather than due to succession.

Studies of succession have a long history in ecology, but rigorous tests of general, unifying principles are rare. One barrier to these tests of theory is the paucity of longitudinal studies that span the broad gradients of disturbance severity that characterize large, infrequent disturbances. The cataclysmic eruption of Mount St. Helens (Washington, USA) in 1980 produced a heterogeneous landscape of disturbance conditions, including primary to secondary successional habitats, affording a unique opportunity to explore how rates and patterns of community change relate to disturbance severity, post‐eruption site conditions and time. In this novel synthesis, we combined data from three long‐term (c. 30‐year) studies to compare rates and patterns of community change across three ‘zones’ representing a gradient of disturbance severity: primary successional blast zone, secondary successional tree blowdown/standing snag zone and secondary successional intact forest canopy/tephra deposit zone. Consistent with theory, rates of change in most community metrics (species composition, species richness, species gain/loss and rank abundance) decreased with time across the disturbance gradient. Surprisingly, rates of change were often greatest at intermediate‐severity disturbance and similarly low at high‐ and low‐severity disturbance. There was little evidence of compositional convergence among or within zones, counter to theory. Within zones, rates of change did not differ among ‘site types’ defined by pre‐ or post‐eruption site characteristics (disturbance history, legacy effects or substrate characteristics). Synthesis. The hump‐shaped relationships with disturbance severity runs counter to the theory predicting that community change will be slower during primary than during secondary succession. The similarly low rates of change after high‐ and low‐severity disturbance reflect differing sets of controls: seed limitation and abiotic stress in the blast zone vs. vegetative re‐emergence and low light in the tephra zone. Sites subjected to intermediate‐severity disturbance were the most dynamic, supporting species with a greater diversity of regenerative traits and seral roles (ruderal, forest and non‐forest). Succession in this post‐eruption landscape reflects the complex, multifaceted nature of volcanic disturbance (including physical force, heating and burial) and the variety of ways in which biological systems can respond to these disturbance effects. Our results underscore the value of comparative studies of long‐term, ecological processes for testing the assumptions and predictions of successional theory.

Our current understanding of the relationship between imperiled species and forest management can benefit from global positioning system (GPS) technologies. Fauna of lateseral stage forests have historically been difficult to detect and track in rugged terrain, leading to challenges in movement characterization and conservation. We investigated movement of California Spotted Owls (Strix occidentalis occidentalis) using automated GPS loggers affixed to 15 owls in the northern Sierra Nevada, California. We used >17,000 locations from individual owls to characterize homerange size, movement distances, and roosting and foraging habitat selection at four spatio-temporal scales (landscape, home range, foray, nightly) during the breeding season (April–August). Additionally, we assessed owl use of Protected Activity Centers (PACs), which are designated by the U.S.D.A. Forest Service to protect nesting and roosting habitat. Our results corroborated some previous findings about habitat requirements of California Spotted Owls, while also revealing new nuances in space use and habitat selection. Roosting and foraging owls selected stands with high canopy cover and large trees at multiple spatio-temporal scales, with foraging owls showing strongest selection at the largest (landscape) scale investigated. Although owls selected for PACs while foraging and roosting, PACs protected less than one quarter of foraging space use (volume of use) and fewer than half of observed roosts during the breeding season. Female owl home ranges were double the size of male home ranges, and distances travelled from the nest by females were 1.3 times greater than distances travelled by males, with non-breeding females travelling farthest and visiting up to six PACs during a single breeding season. Foraying behavior of this sort has not been documented previously in California Spotted Owls. Our findings support protection of later seral stage forest attributes for roosting and foraging California Spotted Owls. Given their selection for later seral forest attributes, strongest evidence of foraging habitat selection at the landscape scale, long distances travelled by owls and limited habitat protection afforded by PACs, habitat connectivity across the landscape is likely an important component for owl conservation, and distribution of current protected areas may be inadequate for this wide-ranging species.

Flood control, via the construction of the Seven Oaks Dam in the Santa Ana River in southern California, has altered habitat in the downstream alluvial wash community and jeopardized the persistence of pioneer plant species that rely on periodic flood-scouring and sand recharge. One species, Eriastrum densifolium ssp. sanctorum (“ Eriastrum ”), an endangered perennial, has been greatly affected and persists in spatially separated populations on successional vegetation terraces. We made “dawn to dusk” observations of pollinators in three phenological stages at four sites, representing young and old seral stages, to identify primary pollinators and to elicit daily, site, and seasonal patterns of visitors. Data were compared to previous observations and correlated with annual rainfall to determine long-term trends. Shifts in pollinator taxa have occurred, with some consistency through time and space, during nine years. The sites with the highest pollinator abundance (older sites) are least suited to Eriastrum . Hummingbirds (prevalent in early season) and the Acton giant flower-loving fly (prevalent in late season) have been consistently present across years, whereas other taxa have varied. A shift from native bees to non-native bees has occurred, although native bees in the families Halictidae and Apidae (Micranthophora and Melissodes) remain important. In general, there was no correlation between taxa abundance and rainfall. Eriastrum appears to be a generalist able to take advantage of the behaviour, cycling, and availability of diverse pollinators daily, seasonally, and annually. !! NOTE !! Supplementary files can be found in the left menu (article tools)

Bacterioplankton play an integral role in aquaculture systems, but our understanding of the succession of bacterioplankton community along intensive shrimp cultivation is fragmentary. Here we used high-throughput sequencing technique to study the dynamics of bacterioplankton community during the process of intensive shrimp (Litopenaeus vannamei) cultivation, and link community changes to physicochemical and biological factors. Community composition varied dramatically over time, supporting the idea of significant unidirectional temporal change in bacterioplankton assemblages, and could be clustered into 4 seral stages by CLUSTER analysis. Different dominant taxa were identified in different seral stages. Furthermore, we used a RMT-based network method to reveal the interspecies interactions among different bacterioplankton and found that these interactions were also dynamic along bacterioplankton succession. Canonical correspondence analysis and Pearson correlations showed that ammonium, nitrite, dissolved oxygen, cryptophytes and green algae constrained community composition by affecting the relative abundance of susceptible species. Besides, Candidatus Aquiluna rubra was identified as the keystone and generalist of the entire network, suggestive of an important role in driving bacterioplankton succession. These findings expand our understanding of the underlying mechanisms of bacterioplankton succession in ponds with intensive rearing shrimp, and suggest that stabilizing environmental variables (e.g. increasing DO, minimizing nutrient pollution and regulating phytoplankton community) could be a useful management tool for promoting and maintaining healthy aquaculture environments.

Assessment of potential forests’ threats due to multiple global change components is urgently needed since increasing exposure to them could undermine their future persistence. We aim to assess the risks to the persistence of monospecific forests in Western Mediterranean Europe posed by climate change, fire, and land-use changes (i.e., deforestation) in the short and medium terms (horizon 2040). We specifically evaluate whether the degree of risk related to the likelihood of hazard occurrence varies depending on seral stage, tree species, and climate gradients. We performed the risk assessment on forests of Catalonia (NE Spain) through a combination of correlative and process-based modeling approaches and future global change scenarios. Overall, climate suitability of forests showed a general decrease by 2040, with the exception of xeric Pinus halepensis forests mainly distributed in the driest climate of the study area. Forest stands dominated by low drought-tolerant species were at higher risk of losing climatic suitability than forests dominated by Mediterranean species. The highest fire and deforestation risks were predicted for forest stands in dry climate where human pressures are higher. Nevertheless, high deforestation risk was also attained outside the driest areas. Deforestation risk was lower in old-growth than in younger stands, whereas old-growth forests in the Wet climate or dominated by Pinus sylvestris were projected to be at higher fire risk than younger forests. Our results suggest that conservation actions should target forest stands in dry climate. Moreover, old-growth forest stands should also be prioritized due to their particular sensitivity to disturbances and their high ecological value.

Tree retention on clear-cuts is a relatively new measure in forestry aimed at ‘lifeboating’ forest species during young seral periods. However, the effectiveness of tree retention for maintaining biodiversity for more than a few years is still poorly known. We investigated lichen persistence in retained buffer strips along small streams after clear-cutting of the surrounding forest, and compared with clear-cuts and un-cut references. Specifically, we compared richness and frequency of red-listed/signal species, calicioids and pendulous species before clear-cutting with 2.5 years and 16.5 years after clear-cutting, and also analysed their colonization-extinction dynamics over time. The results show that the richness of red-listed/signal species and calicioids in buffer strips had declined significantly after 16.5 years, but not after 2.5 years, while frequency displayed a significant difference already after 2.5 years. The richness of pendulous lichens remained relatively stable over time, but the frequency had declined significantly after 16.5 years. In clear-cuts all groups declined more than in buffer-strips (~2–3.5 times more) and the main decline had occurred already after 2.5 years. References remained stable over time. The colonization-extinctions dynamics reflected the richness declines, with high early extinction in clear-cuts and lower but late extinction in buffer-strips, and low (re)colonization. We conclude that retained buffer strips cannot maintain lichen richness over time due to time-lagged extinction, but they are clearly more effective than clear-cuts. Wider buffer strips could potentially reduce tree mortality and decrease lichen extinction. The large amounts of standing dead wood makes buffer strips potential future colonization targets.

We examine patterns of vegetative change in blown-down and scorched forests in the blast zone of Mount St. Helens (USA), 10–26 years after the eruption. We compare trends in community attributes in four post-eruption environments, or site types, defined by severity of disturbance, presence/absence of a protective snowpack at the time of eruption, and seral state (previously clearcut vs. mature/old forests). Permanent plots established in 1980 at 16 sites were sampled at 5- to 6-year intervals between 1989 and 2005. Data on species presence and abundance were used to characterize changes in total plant cover, life-form spectra, species diversity, species turnover, and community composition. Due to the magnitude and heterogeneity of disturbance, vegetation re-establishment was gradual and highly variable among sites. Total plant cover averaged 36–70% after 26 years. Early-seral forbs were dominant except in snow-protected sites, where surviving shrubs were most common. Tree regeneration remained sparse after 26 years (

Ecosystem modification driven by anthropogenic land-use and land-cover change is one of the leading drivers of global biodiversity declines. Simultaneously, ongoing climate change is modifying ecosystems and will have far-reaching impacts on the structure and function of ecological communities. Rising surface temperatures are predicted to have negative effects on plants and animals, but such predictions are typically broad and poorly matched to the spatial scale at which most organisms experience the environment. Microclimate thermal regimes are often moderated by land-cover, and intensive forest management practices have the potential to either ameliorate or exacerbate climate change effects on biota. In this study, we examined the degree to which air temperature varied across an experimental gradient of herbicide application intensity within early-seral forests in the Coast Range mountains of western Oregon. We evaluated stand-level air temperatures in regenerating stands subjected to light, moderate, and intensive herbicide treatments, as well as a no-spray control. We examined whether daily temperature measurements (minimum, mean, and maximum) and their associated coefficients of variation were influenced by herbicide treatments. We found that herbicide treatments had some influence on mean and maximum air temperatures, but not on minimum temperature or on measures of temperature variability. However, temperature effects were small (< 0.5 °C), the direction of these effects were inconsistent, and pairwise contrasts often failed to detect significant differences after accounting for multiple comparisons. Our results suggest that post-harvest vegetation management has limited impacts on fine-scale air temperatures and is unlikely to either amplify or buffer the projected effects of climate change within early-seral forests.

The lichen woodland (LW) is an open-crown subarctic forest distributed principally in North America where it extends from Newfoundland in Atlantic Canada to the Yukon and Alaska. It is the main tree ecosystem of the LW zone north of the closed-crown boreal forest zone, and south of the forest-tundra zone where its cover diminishes progressively toward the Arctic tree line. Growth and development of LWs are closely dependent on dry-mesic, nutrient-poor podzolic soil environments largely distributed on the Canadian Precambrian Shield. The sun-exposed open structure and dominance of lichen species on the dry-mesic soils of LWs determine many of their functions. A diversified cryptogamic flora is thriving in LWs due to reduced competition from vascular plants unable to grow and survive on dry, nutrient-poor soils. Because of the reduced greenhouse effect caused by the open structure and dominance of pale-color lichen mats inducing a greater albedo, LWs exerts a negative microclimatic impact on the environment culminating in the reduction of the frost-free growth season and increase and intensity of frost events. A suite of common, often recurrent, sometime compounding, fine- and large-scale disturbances (including climate change) activates the successional dynamics of LWs and also their historical and present expansion and contraction across the boreal biome. Post-disturbance chronosequences induced by fire, wind and caribou trampling and grazing are producing similar seral communities converging toward the self-maintenance of the LW ecosystem. Long-term succession in southernmost LW sites possibly converges toward the closing of tree canopy and recovery of closed-crown conifer forests (CCCF) in absence of fire. The creation of LW occurred repeatedly during the late Holocene, as well as its extirpation from the northernmost sites (forest-tundra zone) with wildfire as the principal triggering mechanism. LWs are presently unable to transgress the tree line, except for minor advances in small confined sites. Current evidence of the dual distribution of LWs and CCCF in eastern Canada shows that the LW zone is expanding southward into the CCCF zone, where compound disturbances associated with epidemics followed by small to extensive fires are transforming dense forest stands to LWs, a process most likely independent of climate. In terms of ecosystem management, there are concerns about the maintenance of the southernmost LWs within the CCCF zone as poor carbon sinks. Projects involving LW plantation sites in the CCCF zone in eastern Canada are proposed to offset the increased emission of atmospheric gases and thus mitigate climate change.

Tropical peat swamp forests are carbon-rich ecosystems that have been threatened by high rates of land use change (LUC). Despite the ecosystem’s shifts from sequestering carbon (C) to emitting carbon, few studies have quantified the changes in ecosystem productivity associated with LUC in tropical peatlands. This study quantified net primary production (NPP) in intact peat swamp forests (PSF), logged forests (LPSF), early seral sites (ES), and smallholder oil palm plantations (OP) in a peat dome of West Kalimantan, Indonesia. All sites were dominated by peat forest prior to deforestation. The NPP of intact forests was 13.2 Mg C ha−1 year−1 making it among the world’s most productive terrestrial ecosystems, exceeding that of many tropical rainforests and similar to the most productive mangrove ecosystems (12.9 Mg C ha−1 year−1). Land cover change resulted in large shifts in NPP. Logged forest and early seral sites were

Biota dependant on early seral stages or frequently disturbed habitats belong to the most rapidly declining components of European biodiversity. This is also the case for Carabus nitens, which is threatened across Western and Central Europe. We studied one of the last remaining populations of this ground beetle in the Czech Republic, which inhabits post-extraction peat bogs. In line with findings from previous studies, we show that C. nitens prefers patches characterized by higher light intensity and lower vegetation cover. Abundance of females was positively correlated with the cover of plant species requiring higher temperature. In addition, we demonstrate its preference for periodically moist, but not wet or inundated plots, suggesting that the transition between dry heathland and wet peat bog might be the optimal habitat for this species. This hypothesis is further supported by results showing a positive correlation between the abundance of C. nitens and vegetation cover comprising of a mix of species typical for heathland, peat bog, and boreal habitats. Our results show that C. nitens mobility is comparable to other large wingless carabids. The maximum covered distance was ~ 500 m in a month. To ensure the survival of this population, sites of recent peat extraction should be spared from reclamation and afforestation. In contrast, active measures should be taken to facilitate nutrient removal, disturbance of vegetation cover, and the creation of depressions with a humid microclimate. These actions will create a mosaic of heath, bog, and bare ground, which seems to be the preferred habitat of C. nitens at our study site.

Forest canopy gaps play an important role in forest dynamics. Airborne laser scanning (ALS) data provide demonstrated capacity to systematically and accurately detect and map canopy gaps over large forest areas. Digital aerial photogrammetry (DAP) is emerging as an alternative, lower-cost source of three-dimensional information for characterizing forest structure and modelling forest inventory attributes. In this study we compared the relative capacities of ALS and DAP data to map canopy gaps in a complex coastal temperate rainforest on Vancouver Island, British Columbia, Canada. We applied fixed- and variable-height threshold approaches for gap detection using both ALS and DAP data, and validated outcomes using independent data derived via visual image interpretation. Overall accuracies for ALS-derived gaps were 96.50% and 89.50% for the fixed- and variable-height threshold approaches respectively, compared to 59.50% and 50.00% for the DAP-derived gaps, with DAP data having large errors of omission (>88%). We found that 70% of ALS-derived gaps were identified in old seral stage stands (age > 250 years), while 65% of DAP-derived gaps were located in early seral stage stands (age

Longleaf pine (Pinus palustris) forests rely on prescribed fire to limit encroachment of hardwoods and maintain early successional understory communities. However, prescribed fire may alter habitat availability while female eastern wild turkeys (Meleagris gallopavo silvestris) are reproductively active. In addition, the vigor of vegetation regrowth post-fire is impacted by both midstory and overstory stand-conditions which can be a function of stand age. Therefore, the degree to which prescribed fire affects habitat availability and selection of wild turkeys may be a function of both time-since-fire and the age of the stand fire was applied to. We assessed habitat selection of female wild turkeys during their reproductive cycle in a longleaf pine forest managed with frequent prescribed fire. We captured 63 female wild turkeys during 2015 and 2016 on a longleaf pine-dominated landscape in southwestern Georgia, USA, that was managed with 1–3 year fire-return intervals applied to relatively small burn blocks (mean size of burn = 26.02 ha in 2015; 19.84 ha in 2016) on pine stands of varying age-classes. We attached Global Positioning Systems units to individuals and collected hourly locations from 1 March to 15 August. We then used distance-based analyses to estimate daily selection or avoidance of vegetation communities relative to the known reproductive phenology of individual females. Females selected hardwood stands during pre-nesting and post-nesting phases, but avoided them during the incubation phase. Females used open vegetation communities during all phases of reproduction following pre-nesting. Turkeys selected areas burned ≤2 years prior but used different seral stages of pine during different reproductive phases. Specifically, females selected for recently burned mature pine stands during incubation but then selected for recently burned young pine stands, mature pine stands burned 2 years earlier, and open vegetation communities during brooding. Our findings demonstrate that time-since-fire and stand seral age interact to affect how turkeys use pyric landscapes. In general, pine stands providing ample understory vegetation are favored while females are reproductively active. Our data suggests practitioners should try to manage a landscape containing both young and mature pine stands and use prescribed fire to create understory conditions selected by turkeys across all reproductive phases.

Wolves (Canis lupus) in Southeast Alaska inhabit temperate rainforests characterized by patchworks of old-growth and harvested forest stands in various stages of regeneration. Investigating wolf space-use patterns in this landscape may yield information on their tolerance of anthropogenic disturbance in forest ecosystems. Furthermore, identifying shifts in habitat selection throughout the year can provide insights into wolves’ ability to exploit seasonally available resources. We examined seasonal habitat selection of wolves on Prince of Wales Island, Alaska with respect to forest structure, succession, land cover, topography, road densities and habitat predicted to support Sitka blacked-tailed deer (Odocoileus hemionus sitkensis) and salmon (Onchorynchus spp.), the primary and a secondary prey species. We used GPS locations from 13 wolves during 2012–2016 to develop resource selection functions (RSFs). Within their home ranges, wolves selected low elevation, flat terrain with open land cover and low-volume old-growth forests across seasons. During fall and winter wolves preferred clearcuts ≤30 years old, but avoided clearcuts >30 years old and thinned young-growth relative to medium-volume old growth. Habitats with predicted high deer carrying capacities were selected during late summer and fall, and areas close to anadromous streams were important only during summer when salmon were spawning. Areas of high road densities were avoided during denning season and summer, but strongly selected during winter. Our study reveals the potential of coastal wolves to seasonally target prey habitat and adjust to altered landscapes, but successional forests had a limited period of use (

Deforested and converted tropical peat swamp forests are susceptible to fires and are a major source of greenhouse gas (GHG) emissions. However, information on the influence of land-use change (LUC) on the carbon dynamics in these disturbed peat forests is limited. This study aimed to quantify soil respiration (heterotrophic and autotrophic), net primary production (NPP), and net ecosystem production (NEP) in peat swamp forests, partially logged forests, early seral grasslands (deforested peat), and smallholder-oil palm estates (converted peat). Peat swamp forests (PSF) showed similar soil respiration with logged forests (LPSF) and oil palm (OP) estates (37.7 Mg CO2 ha−1 yr−1, 40.7 Mg CO2 ha−1 yr−1, and 38.7 Mg CO2 ha−1 yr−1, respectively), but higher than early seral (ES) grassland sites (30.7 Mg CO2 ha−1 yr−1). NPP of intact peat forests (13.2 Mg C ha−1 yr−1) was significantly greater than LPSF (11.1 Mg C ha−1 yr−1), ES (10.8 Mg C ha−1 yr−1), and OP (3.7 Mg C ha−1 yr−1). Peat swamp forests and seral grasslands were net carbon sinks (10.8 Mg CO2 ha−1 yr−1 and 9.1 CO2 ha−1 yr−1, respectively). In contrast, logged forests and oil palm estates were net carbon sources; they had negative mean Net Ecosystem Production (NEP) values (−0.1 Mg CO2 ha−1 yr−1 and −25.1 Mg CO2 ha−1 yr−1, respectively). The shift from carbon sinks to sources associated with land-use change was principally due to a decreased Net Primary Production (NPP) rather than increased soil respiration. Conservation of the remaining peat swamp forests and rehabilitation of deforested peatlands are crucial in GHG emission reduction programs.

Wildfires pose a unique challenge to conservation in fire-prone regions, yet few studies quantify the cumulative effects of wildfires on forest dynamics (i.e., changes in structural conditions) across landscape and regional scales. We assessed the contribution of wildfire to forest dynamics in the eastern Cascade Mountains, USA from 1985 to 2010 using imputed maps of forest structure (i.e., tree size and canopy cover) and remotely sensed burn severity maps. We addressed three questions: (1) How do dynamics differ between the region as a whole and the unburned portion of the region? (2) How do dynamics vary among vegetation zones differing in biophysical setting and historical fire frequency? (3) How have forest structural conditions changed in a network of late successional reserves (LSRs)? Wildfires affected 10% of forests in the region, but the cumulative effects at this scale were primarily slight losses of closed-canopy conditions and slight gains in open-canopy conditions. In the unburned portion of the region (the remaining 90%), closed-canopy conditions primarily increased despite other concurrent disturbances (e.g., harvest, insects). Although the effects of fire were largely dampened at the regional scale, landscape scale dynamics were far more variable. The warm ponderosa pine and cool mixed conifer zones experienced less fire than the region as a whole despite experiencing the most frequent fire historically. Open-canopy conditions increased slightly in the mixed conifer zone, but declined across the ponderosa pine zone even with wildfires. Wildfires burned 30% of the cold subalpine zone, which experienced the greatest increase in open-canopy conditions and losses of closed-canopy conditions. LSRs were more prone to wildfire than the region as a whole, and experienced slight declines in late seral conditions. Despite losses of late seral conditions, wildfires contributed to some conservation objectives by creating open habitats (e.g., sparse early seral and woodland conditions) that otherwise generally decreased in unburned landscapes despite management efforts to increase landscape diversity. This study demonstrates the potential for wildfires to contribute to regional scale conservation objectives, but implications for management and biodiversity at landscape scales vary geographically among biophysical settings, and are contingent upon historical dynamics and individual species habitat preferences.

Understanding species responses to changes in habitat is a primary focus of biodiversity conservation, especially when assessing widespread anthropogenic disturbance. Extraction of Alberta's subterranean oil sands by wells requires extensive networks of cleared linear disturbances (“in situ” extraction) that result in widespread, but localized increases in early seral habitats. Little is known about biodiversity responses to these disturbances, especially for invertebrates. Here, we investigated how butterflies responded to in situ oil sands developments in the boreal forests of Wood Buffalo region, Alberta, Canada. To assess the magnitude of change associated with different disturbance types, we compared abundance and diversity of butterflies in undisturbed forests with those observed in 3-m and 9-m wide cleared corridors (seismic lines), 60 × 60 m clearings (well pads), and roadside verge habitat. The butterfly assemblage was evaluated based on disturbance type and three measures of landscape change: amount of early seral habitat, edge density, and diversity of natural habitats. Species richness was twice and abundance three-times higher in larger disturbances than in controls, with the narrowest corridors not differing from controls. A model using disturbance type, edge density, and habitat diversity explained 62% of assemblage variation, with the type of disturbance explaining 47%. Higher butterfly abundance and diversity occurred in localized early seral sites, even on 9-m wide corridors, while surrounding landscape characteristics had little effect. Results are consistent with previous studies finding stronger responses in vertebrates to larger disturbances associated with oil sands, confirming that narrower corridors mitigate the effects of oil sands exploration.

Despite their role as keystone organisms, insect pollinator populations have declined across many regions. Although pollinator populations face a multitude of threats, among the most important is habitat loss and degradation. In eastern North America, forested landscapes are thought to serve as strongholds for robust pollinator populations, however, even these high-quality landscapes are increasingly unsuitable for pollinators due to suppression of natural disturbances, which results in mature forests with few floral resources. To enhance landscapes for forest-dependent wildlife, land managers increasingly recognize the value of silviculture for promoting forest regeneration to support early-successional species. Although timber harvest has proven to be an invaluable tool for enhancing forest pollinator habitat, the role of microhabitat components like log landings remains unassessed. Log landings (open areas where harvested logs are loaded for transport) may serve as an important microhabitat component of early seral stands because they are expected to support open conditions and high floral abundance. We sampled 20 log landing/timber harvest interior pairs for bees, butterflies, floral resources, and structural vegetation in the Pocono Mountains of Pennsylvania from June-September 2019. Hierarchical distance models revealed that log landings supported twice as many bees (897 vs 351 bees/ha) and five times as many butterflies (433 vs 88 butterflies/ha) as timber harvest interiors. Likewise, log landings supported about 14 times as many floral resources than timber harvest interiors (109,572 vs 8,431/transect). Among log landings, those with the most floral resources also supported the most bees and butterflies. Collectively, our results support the hypothesis that log landings serve as concentrated resource hubs for bees and butterflies. Future work exploring the role of different plant species (e.g., native vs exotic) in habitat quality for early-successional pollinators would prove useful.

Vegetation biomass is commonly measured through destructive sampling, but this method is time-consuming and is not applicable for certain studies. Therefore, it is necessary to find reliable methods to estimate vegetation biomass indirectly. Quantification of early-seral vegetation biomass in reforested stands in the United States Pacific Northwest (PNW) is important as competition between the vegetation community and planted conifer seedlings can have important consequences on seedling performance. The goal of this study was to develop models to indirectly estimate early-seral vegetation biomass using vegetation cover, height, or a combination of the two for different growth habits (ferns, forbs, graminoids, brambles, and shrubs) and environments (wet and dry) in reforested timber stands in Western Oregon, USA. Six different linear and non-linear regression models were tested using cover or the product of cover and height as the only predicting variable, and two additional models tested the use of cover and height as independent variables. The models were developed for six different growth habits and two different environments. Generalized models tested the combination of all growth habits (total) and sites (pooled data set). Power models were used to estimate early-seral vegetation biomass for most of the growth habits, at both sites, and for the pooled data set. Furthermore, when power models were preferred, most of the growth habits used vegetation cover and height separately as predicting variables. Selecting generalized models for predicting early-seral vegetation biomass across different growth habits and environments is a good option and does not involve an important trade-off by losing accuracy and/or precision. The presented models offer an efficient and non-destructive method for foresters and scientists to estimate vegetation biomass from simple field or aerial measurement of cover and height. Depending on the objectives and availability of input data, users may select which model to apply.

Lodgepole pine (Pinus contorta var. latifolia Engelm.) ecosystems of central British Columbia face cumulative stresses, and management practices are increasingly scrutinized. We addressed trade-offs between “light-on-the-land” versus more aggressive silvicultural approaches by examining plant communities and indicator species (non-natives, berry producers, epiphytes, mycotrophs, pine rust alternate hosts) across a gradient of five or six site preparation treatments at the Bednesti trial (established 1987). We tested whether more severe site preparation (i) caused plant community composition to diverge from a 35- to 46-year-old reference forest, (ii) accelerated succession by hastening crown closure, or (iii) delayed succession by promoting seral species. Nonmetric multidimensional scaling (NMDS) ordination showed all treatments converging toward the reference forest composition. At 10 years, succession was incrementally delayed by more severe treatments; at 25 years, only burned windrows were still delayed. Mixed-effects models based on site preparation severity were better than crown closure models for 11 of 13 variables tested, suggesting that mostly belowground processes drive succession in these infertile ecosystems. Invasive hawkweeds persisted on all treatments at 25 years. Limited, contradictory data did not support using mechanical or fire treatments to reduce alternate hosts of pine stem rusts. Long-term trials such as Bednesti highlight the need for ecosystem-specific strategies and diverse approaches to accommodate conflicting benefits and risks of disturbance in forests.

Ecologists traditionally use environmental parameters to predict successional shifts in compositional characteristics of local species assemblages (environmental control). Another important focus in ecology is to understand functional roles of species assemblages in determining local environmental properties (diversity control). Then, the question emerges: which is the cause, and which is the consequence? To clarify the causal relationships between species assemblages and environmental properties, we focused on seral changes in species/functional diversity of vascular plants in tundra ecosystems of the High Arctic. We found that, although species richness was influenced by soil properties in the earlier stages of primary succession, the causalities were reversed in the later stages. We also found functional differentiation among coexisting species in the later stage, suggesting that the 'complementarity effect' of diversity on ecosystem functions likely increased with ecosystem development through time. By contrast, particular species had little disproportional influence on soil properties, suggesting that the 'selection effect' as an alternative mechanism was less important. This result was likely attributed to the importance of facilitation in the marginal High Arctic environment. Plant-microsite associations are shaped by feedback mechanisms and therefore, neither plant nor microsite is a single absolute predictor of the other. Although our observational study has limitations, we demonstrates a possibility that the relative magnitude of the influence of one on the other can change in the process of succession, emphasizing that the causalities underlying biodiversity-ecosystem function relationships change through succession.