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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.

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.

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.

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.

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.

Habitat disturbance threatens woodland caribou (Rangifer tarandus caribou) by altering inter-tropic relationships, which causes predation rates to increase. Of particular concern is the increase in early seral vegetation in high-elevation caribou summer habitat created by the recent expansion of logging into these forests. Deep snow confines the relatively abundant moose (Alces alces) population to valleys during winter, but in summer they can move up slope, where their spatial overlap with caribou increases. Wolves (Canis lupus) follow moose, their primary prey, up slope and occasionally encounter and kill caribou. We tested the hypothesis that early seral vegetation in high-elevation cutblocks (i.e., logged areas) attracts moose into mountain caribou summer habitat, and thereby increases the spatial overlap between caribou, moose, and wolves. To test our hypothesis, we examined how moose selection for early seral vegetation changed with elevation, how moose used undisturbed habitat, and how the proportion of early seral vegetation at high elevations in a moose home range was related to the amount of time moose spent at high elevations. Moose selection for cutblocks increased with elevation; however, when moose were at high elevations they spent the majority of their time in old-growth forest where they were likely browsing on understory shrubs, and the area of high-elevation cutblocks in moose home ranges did not affect the amount of time moose spent at high elevations. When we further explored the relationship between the amount of early seral vegetation at high elevations and the amount of time moose spent at high elevations, we found moose spent more time at high elevations when total early seral vegetation (from natural sources and cutblocks) increased, but there was little evidence that either type, on their own, influenced moose to use higher elevations. We conclude that although moose select cutblocks, the influence of high-elevation cutblocks on moose was minor in our study. Our results and those of other studies suggests low-elevation logging in moose winter ranges has led to an increased number of moose, and likely has a greater effect on moose distribution than logging at higher elevations. These insights can help guide management of apparent competition between moose and caribou. © 2017 The Wildlife Society.

Questions Our study evaluated how species composition and plant traits that indicate functioning condition in fens responded to grazing cessation over time in an arid ecosystem of the western US. The specific questions addressed were: (1) how does livestock exclusion influence species composition in fens; (2) is grazing cessation associated with shifts in species functional traits that indicate fen condition; and (3) what is the pattern of response to livestock exclusion over time? Location Plumas National Forest, CA, US. Methods We studied paired fenced and unfenced study sites in two fens to examine the effects of livestock exclusion. Parallel transects were established at each site, and plant species and ground cover were repeatedly surveyed, once prior to and multiple times following treatment, using 0.01 m2 frequency frames. We used NMDS to analyse species composition, RLQ and fourth-corner analysis to evaluate species functional traits and environmental variables, and linear mixed effects models to examine differences in responses between fenced and unfenced study sites over time. Results After fencing, we observed unexpected shifts in species composition and plant functional traits. Grazed sites were associated with peat-forming obligate wetland, moss and sedge species, while fenced sites were characterized by non-peat-forming facultative upland, and upland forb, grass and early seral species. Species composition also varied between sites and sample years. Conclusions We found that livestock exclusion strongly affects plant species composition in fens, including promoting species with functional traits that indicate a loss of functioning condition, such as ruderal and upland species. Possible explanations for these observed shifts include: (1) biomass accumulation in the absence of herbivory, (2) competitive exclusion in fenced sites, (3) succession, (4) the abiotic conditions of our study sites, particularly hydrology and nutrient status, and (5) interactions among these factors. We conclude that degradation of fen wetlands caused by livestock grazing in the arid western US may not be reversed by excluding livestock alone.

Pinyon-juniper (Pinus-Juniperus) persistent woodland (PJPW) is widespread in western North America. This study examined changes in PJPW on the South Rim of Grand Canyon National Park (GCNP), Arizona, USA based on resampling study plots established in 1935 that are the earliest-known, landscape-level, quantitative documentation of PJPW. Resampling provided data essential to understanding post-1935 dynamics and current conditions, as well as developing ecologically based management practices. Plots were divided into Core PJPW, Transition PJPW-Ponderosa Pine Forest (PJPW-PPF), and Seral PJPW. These differed greatly in their post-1935 vegetation dynamics. Core PJPW experienced high mortality of mid-diameter Juniperus osteosperma (JUOS) and Pinus edulis (PIED), large losses of total basal area, and increases of small-diameter JUOS. In context of other research, these changes indicate drought during 1953–1956, 1959–1964, and 2002–2011 led to increased mortality of JUOS and PIED and that Core PJPW is a dynamic system with phases of tree recruitment and mortality related to climate. In contrast, Transition PJPW-PPF was generally stable, likely as a result of less drought stress at the relatively high elevation where PJPW intergrades with PPF. Seral PJPW plots were early successional in 1935 and provided a uniquely long, quantitative documentation of succession. They changed most among the PJPW subtypes with large increases in total tree density and basal area as plots transitioned into tree-dominated successional stages. Current conditions of Core PJPW in GCNP provide a model for restoration of PJPW in areas of similar environment. Elsewhere, managers should consider using contemporary data from the area’s least-disturbed PJ vegetation. In general, the ultimate goal should be to restore to the least-altered present, not attempt to re-establish the past. Likewise, findings suggest ongoing management of PJPW in protected areas should not focus on restoration of historical stand structure and composition, as done in PPF. Instead, management should emphasize leaving naturally occurring processes unimpaired. These include disturbances such as stand-replacing fire and native insect outbreaks that historically led to varied spatial and temporal stand composition and structure. However, active management may be needed when modern anthropogenic factors have potential to substantially alter key processes, e.g., if increasing cover of invasive plants such as cheat grass (Bromus tectorum) is likely to change the historical fire regime. Also, management plans for adjacent vegetation types such as PPF, shrublands, and grasslands need to consider potential short- and long-term impacts on PJPW. Additional challenges to management of PJPW are likely to arise with further climate change.

Fire was the dominant ecological process controlling forest structure and succession in western North American conifer forests for thousands of years. Because fires are now suppressed, and because widespread logging has greatly altered vegetation structure, land managers often use estimates of pre-Euro-American settlement forest conditions to help guide restoration actions. It follows that it is important to fully understand the characteristics of pre-Euro-American settlement fire regimes. Percentages of high-severity fire, fire rotation period, and proportions of early, mid, and late developmental forests are intricately and inextricably linked. Early twentieth century vegetation maps that appear to reflect aspects of pre-settlement forest conditions demonstrate that large patches of montane chaparral, which is often an early seral community in yellow pine-mixed conifer forests, were mostly restricted to steep south-facing canyon slopes at higher elevations associated with fir or subalpine forests. When resampled to a 16 ha minimum mapping unit, we found that an early twentieth century vegetation map shows montane chaparral occupied only about five percent of the landscape outside of areas that were highly impacted by gold rush era mining. We found that successional modeling suggests that similar levels (7 %) of high severity per fire in pre-settlement yellow pine-mixed conifer forests in the Sierra Nevada would permit about half of the forested area to reach late development state, consistent with other estimated amounts of pre-settlement old-growth forests. In contrast, we found that high levels (30 %) of high severity per fire—the current average—would result in only about 13 % of forests in a late development state. We do not see evidence that large proportions of high-severity fire were typical during pre-settlement fires in yellow pine-mixed conifer forests in our study area.

Shrublands are largely represented in Europe being diversified into several types. They are found in primary stations, usually on shallow soil sites of rocky places and steep slopes, in which they were differentiated along history and evolution. However, the overwhelming majority of the currently existing shrublands are in secondary stations, as seral stages of forests, being favored by humans by means of the traditional land use systems, particularly extensive husbandry and farming. They often form hedgerows for fencing rural properties, most of them by spiny shrubs such as brambles, roses and blackthorns. This vegetation produces abundant organic matter and keeps the soil in good conditions of fertility. Shrublands also host a large number of small animals, particularly butterflies, and provide abundant fleshy fruits for seed dispersal which fodder many birds. The conservation of the reticulated hedgerows landscape, known as bocage, is a relevant issue for the preservation of the structural complexity and biodiversity of the terrestrial ecosystems in temperate Europe. The modern tendency towards more technological exploitation systems in some regions, parallel to the rural abandonment in others, is leading to the reduction of this habitat type all over Europe.

The natural range of variation (NRV) is an important reference for ecosystem management, but has been scarcely quantified for forest landscapes driven by infrequent, severe disturbances. Extreme events such as large, stand-replacing wildfires at multi-century intervals are typical for these regimes; however, data on their characteristics are inherently scarce, and, for land management, these events are commonly considered too large and unpredictable to integrate into planning efforts (the proverbial "Black Swan"). Here, we estimate the NRV of late-seral (mature/old-growth) and early-seral (post-disturbance, pre-canopy-closure) conditions in a forest landscape driven by episodic, large, stand-replacing wildfires: the Western Cascade Range of Washington, USA (2.7 million ha). These two seral stages are focal points for conservation and restoration objectives in many regions. Using a state-and-transition simulation approach incorporating uncertainty, we assess the degree to which NRV estimates differ under a broad range of literature-derived inputs regarding (1) overall fire rotations and (2) how fire area is distributed through time, as relatively frequent smaller events (less episodic), or fewer but larger events (more episodic). All combinations of literature-derived fire rotations and temporal distributions (i.e., "scenarios") indicate that the largest wildfire events (or episodes) burned up to 105 -106 ha. Under most scenarios, wildfire dynamics produced 5th-95th percentile ranges for late-seral forests of ~47-90% of the region (median 70%), with structurally complex early-seral conditions composing ~1-30% (median 6%). Fire rotation was the main determinant of NRV, but temporal distribution was also important, with more episodic (temporally clustered) fire yielding wider NRV. In smaller landscapes (20,000 ha; typical of conservation reserves and management districts), ranges were 0-100% because fires commonly exceeded the landscape size. Current conditions are outside the estimated NRV, with the majority of the region instead covered by dense mid-seral forests (i.e., a regional landscape with no historical analog). Broad consistency in NRV estimates among widely varied fire regime parameters suggests these ranges are likely relevant even under changing climatic conditions, both historical and future. These results indicate management-relevant NRV estimates can be derived for seral stages of interest in extreme-event landscapes, even when incorporating inherent uncertainties in disturbance regimes.

We searched for patterns in species composition and richness of mid-seral communities developed on abandoned charcoal hearths that might be induced by differences in succession progress and forest context. One phytosociological releve was performed on each of the 22 charcoal platforms located in beech (Anemono apenninae-Fagetum) and oak-hornbeam forests (Doronico-Carpinetum). The ratio of forest understorey to non-forest species richness (F/nF) at plot level was used as a proxy for the succession progress. There was a sharp differentiation of plant communities due to their floristic resemblance with the understory vegetation of the forest type in which they were integrated. Nevertheless, these mid-seral communities still contained a number of nitrophilous weeds that were remnants of the preceding pioneer assemblages. A subgroup of communities (integrated in the beech forest) that lacked the non-forest species mentioned above (high F/nF ratio) could be ascribed to a more advanced seral stage. Species richness on charcoal platforms was not related to forest type, but that might be the consequence of the small sample size. Instead, the number of species decreased steadily with increasing F/nF ratio, which is consistent with the predictions emerging from the paradigm of ecological succession. The forest context accounted for most of the observed floristic dissimilarity between these mid-seral communities. Differences in succession progress seem to be traceable through the number of species, which declines towards more mature stages. The observed communities shared probably the same type of pioneer plant assemblage (Alliario-Chaerophylletum temuli) in the preceding seral stage.

The effect of topography on wildfire distribution in the Canadian Rockies has been the subject of debate. We suspect the size of the study area, and the assumption fire return intervals are distributed as a Weibull distribution used in many previous studies may have obscured the real effect of topography on these fire-regulated ecosystems. The objective of this study was to quantify the effects of elevation, aspect, slope and dominant species on probabilities of burning. The study area covered three natural subregions: Subalpine, Montane, and Upper Foothills of the Rocky Mountains of southern Alberta, Canada. Fire return interval (FRI) data from 870 fire history sampling sites were stratified by subregion and analyzed with the non-parametric Kaplan-Meier survival model and Cox Proportional Hazards (PH) regression model for survival data. The natural subregions were found to have distinct FRI distributions. The Kaplan-Meier probability median historical (pre-1948) FRI values ranged from 26 to 35 years for the Montane, was 39 years for the Upper Foothills and ranged between 65 and 85 years for the Subalpine. Within each subregion elevation was the lead predictor variable influencing probabilities of burning, and its significant PH ratio indicated the effect of elevation was maintained through time. For every 100 m of increased elevation, the probability of burning decreased by 12%, 21% and 33% for the Montane, Upper Foothills and Subalpine, respectively. Aspect was only significant in the Subalpine with a PH ratio indicating warm aspects are twice as likely (105%) to burn than cool aspects. The combined topographic elements of high elevation and cool aspect produce the longest FRIs and are where fire refugia (old growth) tend to form. A salient finding of our study was the multiplicative effect that cool aspect has on burning probabilities of forests located at low or high elevation, as well as the interchangeable effect of some topographic combinations in the Subalpine. Our findings do not support the established assumptions from previous studies that the Little Ice Age was responsible for a change in the burning rate, nor that probabilities of burning are spatially homogeneous in mountain landscapes. The combined effect of aspect and elevation on FRIs need to be integrated when writing fire prescriptions for ecological restoration, and be part of adaptive forest management strategies working towards maintaining fire refugia patches. Timber managers aiming to emulate natural disturbances will also need to consider the effect of topography when planning seral stage distributions in mountainous landscapes.

Question Some of the last remaining grassland communities of the Pacific Northwest Bunchgrass Region (PNWBR) in North America are found in canyon grasslands, primarily because the rugged topography has left many of these associations untouched by agricultural development. However, there have been no prior examinations into how canyon grassland communities change over the long term or how topography relates to these changes. In this study, we examined how successional stages changed over a 33-yr time period and which topographical variables were most related to these long-term outcomes (elevation, aspect or slope). We predicted that areas with more gentle slopes (

This study was conducted in order to examine the influence of long-term volcanic activity on vegetative succession and growth on the slope of Sakurajima in southern Kyushu, Japan. We investigated the vegetation, depth of the volcanic ash layer, and dry density and pH of the surface soil at six places on the north-northwestern slope, 2.3–3.4 km from the Minami-dake crater, where a layer of pumice stone was deposited by the Taisho eruption in 1914. The height and diameter at breast height (DBH) of the trees increased with increasing distance from the Minami-dake crater, as did the number of individuals and species, and basal area. The Shannon–Wiener diversity index (H′) demonstrates that vegetative succession is significantly affected by distance from the Minami-dake crater, as areas farther from the crater exhibited later seral stages. Comparison of the diversity index and species number of the crater region with that of the climax forest in Kagoshima indicates that vegetative growth alone cannot advance succession in the study area, as the local vegetative community is heavily influenced by the harsh environmental conditions associated with continual exposure to long-term volcanic activity. Seral stage, ash layer depth, dry density, and pH of the soil surface layer are governed by distance from the Minami-dake crater. The results of this study indicate that conditions for vegetative growth and succession improve with increasing distance from the source of constant volcanic activity. Thus, soil development is promoted by the acidification of the soil, which decreases the dry density and pH of the soil surface layer. The introduction of plant species resistant to volcanic ash and gas is recommended to promote soil development and improve the infiltration capacity of the soil.

For the management of forest harvesting it is important to understand the processes that impact the re-colonisation of disturbed forests. Edge effects into disturbed forests have been identified as having important impacts on the re-colonisation of both flora and fauna. In a study system located in southern Tasmania, we investigated whether bryophyte colonisation of harvested forests was impacted by edge effects from a standing mature forest (forest influence) and if this effect persisted through time. We tested this by placing transects across a mature/regeneration forest boundary, then recording bryophyte community composition from the ground and coarse woody debris at set distances from the edge. A chronosequence of harvested forest ages (∼7, ∼27 and ∼45 years post harvesting) was used to determine if forest influence persisted through time. Models generated by non-linear canonical analysis of principal coordinates (NCAP) predicted the depth of forest influence, and ‘distances among centroids’ inferred the magnitude of forest influence. Results showed that bryophyte composition in regeneration forests responded to distance from a mature edge. Locations closer to a mature edge had greater similarity in community composition with mature forests. This study also showed that the response of bryophytes to forests influence persisted though time, even after canopy closure. Overall, mature forest species tended to be aided and early seral species restricted by forest influence. However, responses were species-specific and varied with forest age. The colonisation success of mature forest associated species was improved by forest influence; these species are typically at most at risk of being eliminated after disturbance. This result highlights the need to consider edge effects in management. The impact of forest influence on bryophytes therefore has the potential to be used in the design of areas to be harvested.

In the dry forests of the western United States frequent fires historically maintained a diversity of habitats in multiple seral stages. Over the past century, fire suppression and preferential harvest of large trees has led to a densification and homogenization of forests, making them more prone to larger and more severe wildfires. In response, fuel reduction treatments have become common practice in the management of dry western forests. However, the effect of fuel reduction treatments on late seral forest species, such as the Northern flying squirrels, remains a management concern. We captured and marked Northern flying squirrels within mixed conifer forest in the Stanislaus–Tuolumne Experimental Forest (California) on a continuous trapping grid (∼1400 traps) spanning a 120-ha study landscape in which 24 4-ha units were subject to different fuel reduction treatments (variable thin, even thin, and control, all with or without prescribed burning). The study spanned two pre-thinning and three post-thinning years. We divided the study landscape into three blocks (two with treatments, one control only). For each block we analyzed data with spatial capture–recapture models to estimate Northern flying squirrel density, and tested whether canopy closure before and after thinning and percent area burned were important predictors of density. Northern flying squirrel densities varied from 0.168 (SE 0.086) to 0.808 (SE 0.094) individuals/ha across blocks and years. Densities varied by year, independent of treatments. Percent area burned was not an important predictor of density. The effect of canopy closure was variable, but more consistently positive after thinning reduced overall canopy closure. When considered by treatment type, densities were highest in control and burn only units, and lowest in thinned units. Whereas thinning had negative effects on Northern flying squirrel density on the scale of a thinning treatment unit, our results suggest that these effects were largely absorbed by the heterogeneous landscape, as animals shifted their distribution into un-thinned areas without a decline in overall density. This highlights the need to incorporate the landscape context when evaluating the effects of forest management on wildlife.

A variety of nonprairie landscapes, including pastures, crop fields, and unmanaged seral ground, are being restored to native prairie on a yearly basis. Seldom is the seed bank associated with these nonprairie lands taken into account in the restoration process. We examine the seed bank potential of nonprairie lands and the relationship between aboveground vegetation and seed bank composition at the largest grassland restoration east of the Mississippi River, the Midewin National Tallgrass Prairie (U.S.A.), by surveying six land management histories: remnant prairie, restored prairie, new pasture, active pasture, old field, and crop field. Both aboveground vegetation and seed bank composition varied with land management history. However, species composition of aboveground vegetation differed significantly from the species composition of the seed bank irrespective of land management history. Aboveground vegetation carried a higher proportion of the seed bank flora than vice versa. In contrast to s...

Partial harvesting methods are generally more similar to the natural dynamics of broad-leaved forests than clear cutting. However, their effects on biodiversity are still poorly understood. We investigated the effects of selection cutting on the occurrence of a large epiphytic bryophyte, Neckera pennata, in a northern hardwood forest of New Brunswick, Canada. Twenty-eight forest stands were selected, representing two contrasting forest management practices: 5–9 years old, first-entry selection cuts and untreated stands that had been subjected to low-intensity single-tree cutting at least 35 years earlier. Within each stand, we quantified the presence–absence of N. pennata on 36 trees and measured selected forest stand variables. Although N. pennata had persisted in post-harvest stands, its frequency of occurrence on maple trees was only 7% there, compared to 39% in untreated stands. The density of large-diameter sugar maple trees and crown cover were the most important factors predicting the frequency of N. pennata at the stand level. Tree diameter was also a strong predictor of N. pennata’s presence at the tree level and the occupancy of large-diameter maples was almost twice as high in untreated stands as in selection cuts. However, the occupancy of large-diameter maples relative to smaller maple trees was much higher in selection cuts, possibly due to dispersal limitations resulting from reduced connectivity of large-diameter host trees. Taken together, our findings suggest that (1) large trees from older seral stages are a prerequisite for the long-term persistence of N. pennata in managed forests and that (2) they are therefore particularly important for managers to retain in selection cuts. Further, since our results indicate that reduced crown cover in selection cuts has a negative effect on N. pennata, the benefit of retaining large host trees would probably increase if buffered within retention patches of maturing trees. Finally, since host tree diameter clearly is a very important factor for the presence of N. pennata, any extension of the harvest rotation would be beneficial.

Premise of research. We sought to determine the role of flowering in recovery of understory herbs from a major disturbance and to determine the effects of plant and environmental factors on flowering patterns.Methodology. We counted flowering and nonflowering shoots in permanent plots eight to 10 times over a 30-year period for all 48 understory herb species in four subalpine old-growth conifer forests that received tephra (aerially transported volcanic ejecta) from the 1980 eruptions of Mount St. Helens, Washington. We defined two measures of flowering and related them to environmental and plant characteristics.Pivotal results. Patterns of flowering varied widely among species both among and within growth forms. Flowering increased with time, especially where it was initially low (for evergreen clonal plants, species that also grow in early seral habitats, and plants in deep tephra and from herb-poor sites). Some significant differences that occurred during the first 20 years disappeared by year ...

Terrestrial wildlife communities are often overlooked as components of ecosystem restoration following dam removal. However, a diverse mammalian fauna colonizes habitat on dewatered reservoirs and may influence restoration processes. We studied mammalian colonization and ungulate herbivory from 2014 to 2018 following the removal of two large dams on the Elwha River in Washington, USA. Specifically, we examined (1) small mammal colonization and (2) Roosevelt elk (Cervus elaphus roosevelti) and Columbian black-tailed deer (Odocoileus hemionus columbianus) distribution and browsing pressure in association with revegetation efforts. We live-trapped small mammals on two former reservoir beds and monitored deer and elk use by conducting pellet group counts and quantifying ungulate herbivory at plots throughout the former reservoir beds and an adjacent reference site. We found that the proportion of deciduous riparian species on plots best predicted occupancy for mice, shrews, and voles. Small mammal species diversity was best explained by the proportion of logs and conifers on study plots. Roosevelt elk presence and browsing intensity on willows (Salix spp.) and black cottonwood (Populus balsamifera ssp. trichocarpa) varied both spatially and temporally, affecting the stature and potentially the growth trajectories of these species. Early seral restoration of these terrestrial habitats has included the presence of a diversity of granivores, insectivores, and herbivores, with elk demonstrating the strongest influence over portions of the study area. Small mammal colonization complements revegetation succession and demonstrates restoration of ecological processes, while large ungulates may be playing a more substantial role in shaping revegetation.

The Uinta Mountains lie along an important transition between major climate regimes and thus are sensitive to major climatic changes and consequent vegetation shifts. Two pollen cores from montane Uinta sites on the Utah–Wyoming border (Marsh Lake Bog and Camp Bog, respectively) were used to analyze vegetation shifts from the latest Pleistocene through the Holocene. The records correspond with those from adjacent portions of the Rocky Mountains, all demonstrating a major shift from alpine steppe to open spruce parkland at ~ 11,700–11,200 cal yr BP. A second major shift to lodgepole pine forest began at ~ 8400 cal yr BP at Marsh Lake Bog and could have been a direct response of the dominant species to warmer conditions and/or the result of subtle changes in the competitive hierarchy of tree species near a sensitive ecotone. The difference in the rate and full expression of lodgepole forest development (taking nearly 2000 years longer at Camp Bog) was probably due to a set of complex and local factors, such as cold air drainage and landscape position. Lodgepole pine forest persisted throughout the late Holocene and appears to be the long-term regional “climax” forest, rather than a seral habitat. Fire does not appear to have triggered the middle Holocene shift from spruce-dominated to lodgepole pine-dominated forests in this area but may have contributed to its long-term persistence to the present day.

On the basis of vegetation data by point quarter sampling method, the natural forest of Jirisan(Mt.)was classified into eight forest types by cluster analysis. They were Quercus mogolica forest type, Fraxinusmandshurica – Betula costata forest type, Mixed mesophytic forest type, Abies koreana forest type, Carpinuslaxiflora forest type, Quercus serrata forest type, Pinus densiflora forest type, and Quercus variabilis foresttype. Then, succession index was estimated for each forest type so as to evaluate succession processcomparatively among forest types. The results showed that Carpinus laxiflora forest type had highest successionindex of 219.7, followed by Mixed mesophytic forest type with little difference of the index of 218.3. Pinusdensiflora forest type had lowest index. Succession indices were hardly correlated with species diversity indicesof forest types. We presumed that the higher value of succession index a forest type had, the closer toward theclimax forest. However, the estimated index was not supposed to be absolute level of successional stage, but itcould play a role of comparative assessment in the position of the seral stage among forest types.Key words: forest type classification, forest succession, Jirisan, succession index, species diversity

Improved recording of less popular groups, combined with new statistical approaches that compensate for datasets that were hitherto too patchy for quantitative analysis, now make it possible to compare recent trends in the status of UK invertebrates other than butterflies. Using BRC datasets, we analysed changes in status between 1992 and 2012 for those invertebrates whose young stages exploit early seral stages within woodland, lowland heath and semi-natural grassland ecosystems, a habitat type that had declined during the 3 decades previous to 1990 alongside a disproportionally high number of Red Data Book species that were dependent on it. Two clear patterns emerged from a meta-analysis involving 299 classifiable species belonging to ten invertebrate taxa: (i) during the past 2 decades, most early seral species that are living near their northern climatic limits in the UK have increased relative to the more widespread members of these guilds whose distributions were not governed by a need for a warm micro-climate; and (ii) independent of climatic constraints, species that are restricted to the early stages of woodland regeneration have fared considerably less well than those breeding in the early seral stages of grasslands or, especially, heathland. The first trend is consistent with predicted benefits for northern edge-of-range species as a result of climate warming in recent decades. The second is consistent with our new assessment of the availability of early successional stages in these three ecosystems since c. 1990. Whereas the proportion and continuity of early seral patches has greatly increased within most semi-natural grasslands and lowland heaths, thanks respectively to agri-environmental schemes and conservation management, the representation of fresh clearings has continued to dwindle within UK woodlands, whose floors are increasingly shaded and ill-suited for this important guild of invertebrates. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, ●●, ●●–●●.

We examined the influence of surroundings, i.e. proximity effects, on the course of spontaneous vegetation succession using two data sets. In the first data set, we tested the effects of surrounding vegetation (woodlands, wetlands, grasslands, and synanthropic) on succession in various disturbed habitats in the Czech Republic by comparing successional sites with more natural vegetation within 100 m and at 1 km from each site. The habitats included old fields, gravel-sand pits, spoil heaps from black coal mining, industrially extracted peatlands, and acidic stone quarries. We found that, with the exception of wetlands, the influence of the vegetation types on seral vegetation was nearly always significant using marginal and partial Canonical Correspondence Analyses. In the second data set, which included 27 limestone quarries, we compared species lists outside (up to 100 m apart) and inside the quarries using Detrended Correspondence Analysis and the Sorensen similarity index. We found much higher species similarity between outside and inside particular limestone quarries than among the quarries themselves and among their surroundings, which also indicates that the seral vegetation is decisively influenced by the surroundings. We argue that restoration ecologists should carefully consider the nature of the surroundings of disturbed sites because of its profound impact on restoration processes. They should conduct inventories and prescribe some restoration measures not only inside a restored site, but also in its surroundings.

We investigated successional vegetation on river sediments along the Nakdong River in South Korea at the time when a river regulation project, named the Four River Project, was launched. We sampled differently aged stages of succession in 63 plots of 10 × 10 m in 2010 using species cover estimations. To explain the observed species composition, we considered the following environmental variables: successional age, distance from the estuary, altitude, elevation above the river water line, texture of the substrate (silt, sand and gravel content) and cover of forest around each site within a radius of 1 km. We used ordination techniques to relate plant community characteristics to environmental variables. We distinguished three main successional vegetation types based on their floristic composition, which included especially a variety of willow species. Besides the cover of forest and certain components of substrate texture, all the variables exhibited significant effects on species composition of the vegetation over the course of succession. The most important factors determining the seral vegetation were the altitudinal gradient and successional age. Environmental factors in the riverine landscape together form a complex riverine environment and determine the vegetation pattern. Unfortunately, this environment has been largely destroyed by the massive river regulation project, but our results indicate that, under certain conditions, the riverine vegetation has a potential to at least partly recover even after such a large-scale disturbance.

Complex early seral forests (CESFs) occupy potentially forested sites after a stand-replacement disturbance and before re-establishment of a closed-forest canopy. Such young forests contain numbers and kinds of biological legacies missing from those produced by commercial forestry operations. In the Sierra Nevada of California, CESFs are most often produced by mixed-severity fires, which include landscape patches burned at high severity. These forests support diverse plant and wildlife communities rarely found elsewhere in the Sierra Nevada. Severe fires are, therefore, essential to the region's ecological integrity. Ecologically detrimental management of CESFs, or unburned forests that may become CESF's following fire, is degrading the region's globally outstanding qualities. Unlike old-growth forests. CESFs have received little attention in conservation and reserve management. Thus, we describe important ecological attributes of CESFs and distinguish them from early serai conditions created by...

Michx.) forests occur in highly diverse settings across North America. However, management of distinct communitieshas long relied on a single aspen-to-conifer successional model. We examine a variety of aspen-dominated stand types in the western portion of its range as ecologicalsystems, avoiding an exclusive focus on seral dynamics or single-species management. We build a case for a large-scale functional aspen typology based on the existingliterature. Aspen functional types are defined as aspen communities that differ markedly in their physical and biological processes. The framework presented heredescribes two “functional types” and seven embedded “subtypes”: seral (boreal and montane), stable (parkland, Colorado Plateau, elevation and aspect limited, andterrain isolated), and a crossover seral-stable subtype (riparian). The assessment hinges on a matrix comparing proposed functional types across a suite of environmentalcharacteristics. Differences among functional groups based on physiological and climatic conditions, stand structures and dynamics, and disturbance types and periodicityare described herein. We further examine management implications and challenges, such as human alterations, ungulate herbivory, and climate futures, that affect thefunctionality of these aspen systems. The functional framework lends itself well to stewardship and research that seek to understand and emulate ecological processesrather than combat them. We see advantages of applying this approach to other widespread forest communities that engender diverse functional adaptations.Keywords: forests, climate, landscape, classification, biodiversity, adaptive management

Woodland (Plethodontid) salamanders occur in huge numbers in healthy forests in North America where the abundances of many species vary along successional gradients. Their high numbers and trophic role as predators on shredder and decomposer arthropods influence nutrient and carbon pathways at the leaf litter/soil interface. Their extreme niche conservatism and low vagility offer further advantages to the use of these salamanders as metrics of forest ecosystem condition. Mill Creek is a 103 km2 commercially logged redwood forest watershed acquired as parkland where original primary forest is being restored. This study evaluated woodland salamanders as metrics of seral recovery at Mill Creek. Surface counts and body condition were examined in four sets of stands, two early seral, one mature, and one of primary forest (never harvested old-growth). Later seral sites were closer to the coast where fog increased available moisture; younger sites were further inland at higher elevations where fog was reduced. We distinguished the effects of geography and succession using ANCOVA with a PCA-derived landscape covariate. Both geography and succession increased counts of California Slender Salamanders (Batrachoseps attenuatus); advancing succession alone indicated increased counts of Ensatina (Ensatina eschscholtzii). Means and variances in body condition of these two species were lower in older stands; for the Del Norte salamander (Plethodon elongatus) only the means were lower. Coastal proximity increased mean body condition in E. eschscholtzii, but with P. elongatus it was the opposite. We modeled surface counts and body condition along environmental gradients associated with succession. The counts and body condition in two of three species when taken together suggested that the increased structural complexity in late-seral forest stands supported larger populations that appeared to be competing for limited resources and, thus, likely have greater population fitness than those in younger forests. B. attenuatus and E. eschscholtzii proved to be viable metrics of advancing succession with their numbers and body condition providing readily quantifiable measures of ecosystem recovery at Mill Creek.

Annual/perennial and tall/short plant species differentially dominate early to late successional shortgrass steppe communities. Plant species can have different ratios of above-/below-ground biomass distributions and this can be modified by precipitation and grazing. We compared grazing effects on aboveground production and root biomass in early- and mid-seral fields and undisturbed shortgrass steppe. Production averaged across four years and grazed and ungrazed treatments were 246, 134, and 102 g m−2 yr−1 for the early-, mid-seral, and native sites, respectively, while root biomass averaged 358, 560, and 981 g m−2, respectively. Early- and mid-seral communities provided complimentary forage supplies but at the cost of root biomass. Grazing increased, decreased, or had no effect on aboveground production in early-, mid-seral, and native communities, and had no effect on roots in any. Grazing had some negative effects on early spring forage species, but not in the annual dominated early-seral community. Dominant species increased with grazing in native communities with a long evolutionary history of grazing by large herbivores, but had no effects on the same species in mid-seral communities. Effects of grazing in native communities in a region cannot necessarily be used to predict effects at other seral stages.

Sedimentary rocks filling the Boltysh meteorite crater preserve an expanded record of post Cretaceous–Palaeogene (K/Pg) event vegetation destruction and subsequent floral recolonization. A post-destruction barren zone is succeeded by a fern spore spike recording the initial recovery vegetation. The Boltysh fern spore spike is divisible into two phases. Phase 1 is characterized by low abundances of fern spores, whereas the overlying Phase 2 has high fern spore abundances and contains common palm pollen. Comparison of the Boltysh Phase 2 fern spore spike with other palynological records shows strong similarities to the immediately post K/Pg boundary record of the Western Interior, North America. Variation in the composition of the Boltysh palynofloras has been used to define four moisture availability cycles between the K/Pg boundary and the Dan-C2 negative carbon isotope excursion, a period of some 300 kyr. Early post K/Pg event vegetation community recovery followed a common seral successional pathway at rates seen in large igneous provinces, although enhanced by high moisture availability. Continued succession to the first true swamp community was at a considerably slower tempo. The post K/Pg event vegetation recovery was therefore retarded by lack of moisture availability, extending the apparent period of recovery.

The Spanish North Plateau or the Spanish Duero basin is located in the southern foothills of the Cantabrian Ranges in the north-western quadrant of the Iberian Peninsula. It was formed by the action of the Duero river and its tributaries on both the right and left. The climate can be considered continental between dry and humid. The vegetation in this territory is very varied, and several groups can be differentiated based on their structure and physiognomy, and based on the soil and climate variability in this area. These groups are: (1) Forest and woodlands dominated by Quercus rotundifolia, Quercus pyrenaica, Quercus faginea, Juniperus thurifera, Juniperus oxycedrus. (2) Riparian ecosystems formed by willows (Salix neotricha), poplars (Populus alba and Populus nigra), ashes (Fraxinus angustifolia), alders (Alnus glutinosa), elms (Ulmus minor) and shrubby willows (Salix salviifolia, Salix elaeagnos subsp. angustifolia). (3) Seral scrub, including spiny nanoshrublands dominated by Rosa sp. pl., Rubus sp. pl., broom communities formed by several species in the genera Cytisus and Genista, hygrophilous or non-hygrophilous heathlands, with a predominance of species from the genus Erica, secondary scrub communities dominated by Cistaceae and Lamiaceae or Thymus sp. pl. communities, and nitrophilous scrub dominated by Artemisia sp. and Santolina sp. (4) Gypsophilous vegetation. (5) Grasslands of a wide diversity starting with communities of Nardus stricta, and continuing with communities of Celtica gigantea, Poa bulbosa, Agrostis castellana, rushy pastures dominated by Juncus sp. pl., meadows, communities of Festuca elegans subsp. merinoi and Stipa sp. pl. (6) Herbaceous ruderal and assorted vegetation with widely differing communities of the Stellarietea mediae, with both a roadway ruderal character and also present in rain-fed and irrigated croplands and grasslands produced by human and animal action. (7) Aquatic vegetation, including riparian herbaceous communities, peat bogs, lakes and pools communities, reed communities, reed beds, megaforbic communities and pioneer annual and dwarf perennial isoetid communities on periodically flooded bare soils. (8) Salt marshes. (9) Rock vegetation. (10) Vegetation series.

Questions: Grazing may speed or slow secondary succession, and the directionmay depend on seral stage and relative tolerance of native perennial grassescompared with annual invasive species. How does grazing affect successionwhere undisturbed communities have a long evolutionary history of grazing bynativeherbivoresandaretoleranttolivestockgrazing?Location: Shortgrass steppe, North American Great Plains, Colorado (40°49′N,104°46′W),USA.Methods: Ungrazed and grazed early-seral (4–6 yr) and mid-seral (18–20 yr)seeded fields (Conservation Reserve Program) and traditionally grazed nativesteppe were compared for effects on plant composition in relation to changesexpectedfromregionalsuccessionmodels.Results: Recovery towards undisturbed native shortgrass steppe for early- andmid-seralcommunities,respectively,was19%and36%fortotalvegetationcover,5% and 21% for planted native species, 10% and 88% for non-planted nativeperennialgrasses,only0.2%and13%forshortgrasses,andoveralldissimilarityincommunity species compositions was 97% and 68%. In general, grazing effectswere neutral or most often not significant in all years and/or were small in overallcommunitymagnitude.Theearly-seralcommunitydisplayedmorechangesindic-ativeofaslowingofsuccessionwithgrazing(totalvegetativeandgrassbasalcover)rather than reducing invasive species ( species targeted by timing of grazing),although drought had limited the establishment of grazing-tolerant short grasses.The mid-seral community showed more changes consistent with advancing suc-cessional recovery with grazing (overall community dissimilarity, forbs, plantednative perennial grasses, tall grasses and target species). However, non-plantednative perennial grasses responded negatively to grazing in the mid-seral commu-nityandpositivelyinnativeshortgrasssteppewhereoutsideseedwouldoriginate.Conclusions: Grazing effects on particular functional groups and species werenotthesameacrossseralstages,weremixedintermsofspeedingorslowingsuc-cession, and were generally not large at the community level. Evolutionary his-tory of grazing may serve as a general guide but decisions on whether to grazesuccessional grasslands may best be made after assessing whether tolerantperennial short grass species are significant components. Monitoring may thenbe necessary to determine species responses in particular community matrixesandeffectsonsubsequentimmigrationofnon-seedednativeperennialspecies.IntroductionHerbivorymay speed or slowplant communitysuccession,and synthesis as to where or when each may occur hasprimarily been based on studies of specialist herbivores inwoody communities, with only four of 34 cases of largegeneralist grazers in grasslands and none involving live-stock and secondary succession (Davidson 1993). Grazing

Hardwood-dominated riparian forest was surveyed in 83 quadrats on 3 floodplains, 11 lower terraces, and 8 upper terraces along 11 km of Zoar Valley Canyon, a minimally disturbed segment of 5th–6th order Cattaraugus Creek in western New York State, USA. Increment core-based stand ages from 8 to >300 years constituted the longest middle-order riparian sequence yet studied in the East. Comparisons of aerial images starting in 1929 with present-day increment cores indicated trees have reached breast height and persisted on recent lower terraces within at most 6–27 years after deposition, suggesting landform age and type associated primary succession rather than flood-regime driven secondary succession or maintenance of early seral stages. In 2009, the second largest flood since 1940 caused only modest damage even to floodplain stands, supporting this premise. Regressions of stand characteristics on age across the 300-year sequence revealed logarithmic increases in tree diameter and height, stand basa...

Compared with temperate ecosystems, tropical ecosystems will respond differently to increasing nitrogen (N) deposition due to indirect effects on the availability of phosphorus (P). Data in this study were collected from the long-term research plots and controlled experiments in a succession series, including 50-year-old pine forest (PF), 80-year-old mixed pine and broadleaved forest (MF), and more than 400-year-old monsoon evergreen broadleaved forest (MEBF), in southern China to study growth patterns and biogeochemical processes. The results showed that soil total N and available N were significantly higher in MEBF than in the other two forests. Soil available P was significantly lower in MEBF than in PF though the total P was the same. The N/P ratios in living leaves were increasing with succession stages. The standing biomass and productivity of MEBF have been declining over the last 30 years. Our findings suggest that the high N stock in soil pools through atmospheric deposition and self-accumulation in MEBF would require more available P to prevent deficiency that would limit plant growth. However, as more organic matter accumulated and thus, more P was bound in MEBF, there was much less available P in soils. These processes result in significantly higher N/P ratios in living leaves of the old-growth forest, which may be responsible for the decline.

Understanding the effects of land-use on threatened ecosystems is of special relevance for nature conservation. The aim of our study was to use Orthoptera as ecological indicators for succession in Central European steppe grasslands. Orthoptera showed a clear response to succession. Each successional stage harboured a unique assemblage. Species richness of habitat specialists was highest in the earliest seral stages. In contrast, density of all species peaked at the intermediate successional stage. Early successional stages are mostly likely to be preferred by specialized Orthoptera because they provide warm suitable oviposition sites (bare ground) and microclimatic conditions. The density peak in the mid-successional stage probably reflects a trade-off between favourable ambient temperatures for optimal development, sufficient food and shelter against predators. Although all successional stages of steppe grassland are relevant for conservation, early and mid-successional stages are the most important. Consequently, conservation management should aim at re-introduction of a traditional, low-intensive land use for abandoned steppe grasslands. As an optimal land use, we recommend traditional rough grazing with sheep and goats, which creates a heterogeneous habitat structure with bare ground, and avoids the accumulation of litter, favouring Orthoptera.

Few old-field succession studies have been conducted in arid ecosystems and there is some question if classical secondary succession occurs in arid environments. In order to determine if old-field succession does occur under arid conditions, we sampled 40 previously-cultivated sites abandoned over a period of 29–80 years in the Owens Valley, California. We compared vegetation development at these 40 old fields to vegetation composition on 17 adjacent uncultivated reference sites. We were interested in determining if 1) seral communities could be identified, 2) these communities expressed predictable and progressive patterns, and 3) if so, whether the seral patterns indicated divergent or convergent successional pathways. The 57 sites separated into 6 separate seral communities. Two seres were identified, one progressing toward a big sagebrush late-seral community and the other with fourwing saltbush as the characteristic species. Based on multivariate statistical analysis, the two seres were likely to continue on divergent pathways for 100–140 years, after which the saltbush sere may converge toward the late-seral sagebrush community. Both localized and broad-scale factors were important in defining successional patterns in this arid environment. Our results support the concept that classical old-field succession does occur in arid regions.

Periodic flooding alters riverine vegetation community composition; moderate flood disturbance maintains communities at an early seral stage, whereas severe floods may remove entire communities. After disturbance, plants may recolonize riverbeds from refugia. Here, we investigated the morphological characteristics of refugia where riverine plants survived large floods. At three sites, plant communities growing on cobble-bars were surveyed, and the hydraulic characteristics of each site were analyzed. The populations of an indicator plant, Anaphalis margaritacea sub-species yedoensis (Franch. et Savat.) were assessed after major floods in 2004 and 2009. At each survey, the particle size and bed composition were measured, and the critical shear-stress required to move particles at each site was calculated. A one-dimensional flow and the average and local shear-stress at ten different discharges, including that of the largest flood were calculated. The results demonstrate that the A. margaritacea community is maintained at locations where the local shear-stress at peak discharge in large-floods does not exceed a critical value. These conditions were achieved in locations with particular morphological characteristics, where the river is not constrained by levees and is restricted by a downstream narrow-pass; in this reach river width increases with discharge thus limiting the increase in water depth with increasing discharge and allowing the establishment of refugia where plant species may survive large floods. Flooding and reestablishment from refugia maintain a characteristic riverbed community in equilibrium.

Fire is both a widespread natural disturbance that affects the distribution of species and a tool that can be used to manage habitats for species. Knowledge of temporal changes in the occurrence of species after fire is essential for conservation management in fire- prone environments. Two key issues are: whether postfire responses of species are idiosyncratic or if multiple species show a limited number of similar responses; and whether such responses to time since fire can predict the occurrence of species across broad spatial scales. We examined the response of bird species to time since fire in semiarid shrubland in southeastern Australia using data from surveys at 499 sites representing a 100-year chronosequence. We used nonlinear regression to model the probability of occurrence of 30 species with time since fire in two vegetation types, and compared species' responses with generalized response shapes from the literature. The occurrence of 16 species was significantly influenced by time since fire: they displayed six main responses consistent with generalized response shapes. Of these 16 species, 15 occurred more frequently in mid- or later-successional vegetation (.20 years since fire), and only one species occurred more often in early succession (,5 years since fire). The models had reasonable predictive ability for eight species, some predictive ability for seven species, and were little better than random for one species. Bird species displayed a limited range of responses to time since fire; thus a small set of fire ages should allow the provision of habitat for most species. Postfire successional changes extend for decades and management of the age class distribution of vegetation will need to reflect this timescale. Response curves revealed important seral stages for species and highlighted the importance of mid- to late-successional vegetation (.20 years). Although time since fire clearly influences the distribution of numerous bird species, predictive models of the spatial distribution of species in fire-prone landscapes need to incorporate other factors in addition to time since fire.

The Conservation Reserve Program (CRP) is an extensive land use in the United States, which restores cultivated land to perennial vegetation through seeding. Low precipitation and high potential evapotranspiration are major limitations to the establishment and growth of seeded species in semiarid regions. We tested the rate of development of plant functional types across a chronosequence of restored fields using a model of plant succession. We also determined how the seeding of non-native (introduced) relative to native perennial grasses influenced plant community recovery. In contrast to the native shortgrass steppe (SGS), recently seeded CRP fields had high cover of annuals, forbs, C3, and introduced species. The seed mix determined which perennial grasses dominated the plant community within 18 years, but slow establishment prolonged early seral stages, allowed for the spread of colonizing perennial grasses, and limited recovery to less than half the canopy cover of undisturbed shortrass steppe. Species density declined in restored fields as seeded perennial grass cover increased and was lower in CRP fields seeded with introduced compared to native perennial grasses. Plant community composition transitioned to C4 and native species, even if fields were not seeded with these species, and was modified by shifts in the amount and seasonality of precipitation. Thus, in semiarid CRP fields, we found that the potential for recovery depended on time since CRP enrollment, seed mix, and climatic variability. Full recovery, based on similarity to vegetation cover and composition of undisturbed SGS, requires greater than 20 years.

Este estudo teve como objetivo analisar a comunidade arbórea em três estádios sucessionais florestais ciliares na Área de Proteção Ambiental Lagoa de Jacunem, no Município da Serra, ES. Para a caracterização estrutural foram empregadas 60 parcelas de 10 m2, totalizando 0,6 ha amostrado. As parcelas foram distribuídas equitativamente entre cada estádio sucessional, onde foram incluídos os indivíduos com CAP > 15 cm, a 1,30 m do solo. Em cada estádio também foram coletadas amostras compostas de solo para posterior análise química. As áreas apresentaram solos distróficos, sendo por isso pobre em nutrientes e com acidez elevada. Foi amostrado um total de 851 indivíduos, distribuídos em 79 espécies. A diversidade (H') de espécies foi aumentando gradativamente seus valores, sendo 2,70 no estádio inicial, 2,88 no estádio médio e 2,96 no estádio avançado, respectivamente. A equabilidade J' foi de 0,77 nos estádios inicial e médio e 0,73 no estádio avançado. A densidade decresce significativamente (ANOVA; F=6,55; P 15 cm at 1.30 m from the soil. In each stage, it was also collected composed samples of soil for posterior chemical analyses. The areas presented dystrophic soils and therefore low in nutrients and high acidity. It was sampled a total of 851 individuals, distributed in 79 species. The diversity (H') of species was gradually increasing its values, being 2.70 in the initial stage, 2.88 in the middle stage, and 2.96 in advanced stage, respectively. The equability J' was 0.77 in the initial and middle stages, and 0.73 in the advanced stage. The density decreased significantly (ANOVA; F=6.55; P

Sweetclover (Melilotus alba) is a non-native legume that has formed dense and extensive patches along several rivers in Alaska. Our research objective was to determine if sweetclover impacts recruitment of native seedlings in floodplain habitats. To determine if sweetclover impacted recruitment, we conducted a removal experiment along two rivers in interior Alaska. When compared to areas where sweetclover was removed, areas with sweetclover had approximately 50% greater mortality of native seedlings, 25% less recruiting species, and a significant reduction in the quantity of light available to seedlings on floodplain surfaces. To determine if sweetclover shading was a mechanism that limited seedling recruitment, we grew eight common early-successional floodplain plant species in a greenhouse under a range of lighting conditions that were representative of shading under sweetclover. We observed that species restricted to the earliest seral stages of floodplain succession experienced greater reductions in biomass than species that persist into later stages of floodplain succession. Shading seedlings in a greenhouse did not lead to mortality during the growing season. However, when seedlings were over-wintered, we observed that greater shading during the growing season can result in higher seedling mortality. Our study indicates sweetclover invasions have created a novel shade environment in early seral floodplain plant communities, which has the potential to alter community composition. To preserve biodiversity and structure of plant communities, sweetclover should be actively managed to prevent its spread onto additional glacial rivers in Alaska.

Summary 1. Most studies of tree regeneration are limited to particular environments and may not capture variation in the biotic or abiotic factors that regulate recruitment at larger spatial scales. Critical processes such as competition and facilitation can vary spatially, along gradients in resource avail- ability and environmental stress, and temporally, with plant development. 2. We examined patterns of natural tree recruitment and experimentally followed germination and seedling survival of five tree species (pioneer to late seral) in three early successional communities of contrasting bio-physical environments in a rural landscape on ChiloeIsland, Chile. 3. We quantified natural recruitment of juveniles and saplings and assessed relationships between tree density and local environment. We used a removal experiment to test the influence of early suc- cessional vegetation on seed germination and early survival of tree species. In each community, seeds and seedlings were placed in paired experimental plots from which vegetation was removed or left intact (control). To identify potential correlates of germination and seedling survival, we mea- sured light transmittance and soil properties in each plot. 4. In all communities, established vegetation had either a positive or neutral effect on germination and ⁄ or survival although responses varied among life stages and species. Germination and survival were correlated with the lower levels of light in controls, consistent with negative correlations between natural tree densities and light. Vegetation cover was not dense enough to facilitate survival of late successional species, but not too dense to inhibit survival of shade-intolerant or mid-tolerant species. Among communities, natural densities of juveniles were greatest under conditions where experimental germination rates were highest. Seedling height growth was lowest in the community characterized by waterlogged soils, consistent with the naturally low transition rate from juveniles to saplings and a negative correlation between density of shade-intolerant trees and soil moisture. 5. Synthesis. Our experiments indicate strong, mostly positive controls (facilitation) on tree recruit- ment in early seral shrublands with differing bio-physical environments. Benefits of shading are manifested at different stages in the life history. However, community context is critical: variation in seasonal patterns of soil moisture may explain spatial variation in the density and size structure of natural tree recruitment.

This study presents new findings about gender-related spatial distributions of the strictly dioecious tree species Fraxinus mandshurica . The observations were collected in three large field plots in secondary and old-growth forests in northeastern China, covering the 4-year period from 2005 to 2008. Tree diameters were not significantly different between genders in the young secondary forests. In the old-growth forest, however, the diameters of male trees were significantly greater than those of female trees. The sex ratio did not significantly deviate from 1:1 in the secondary forests, but was male-biased in the old-growth forest. Spatial segregation between genders was found in the secondary forests, but male and female trees were spatially independent in the old-growth forest. This research complements the current knowledge about sex ratios in secondary and old-growth forests, and about spatial patterns and intra- and intersexual interactions of the dioecious species, F. mandshurica . The available evidence suggests that male and female individuals show a different response to specific microenvironments in the three forest successional stages, which suggests that there are differences in resource requirements between genders.

Question: How do forest herb species differ from each other in their spatial and temporal dynamics during recovery from volcanic disturbance, and how are dynamics related to species traits? Location: Northeast of Mount St. Helens, Washington, USA. Methods: Following deposition of volcanic tephra in 1980, we measured herb density and cover in permanent 1-m2 plots during 1980-2005 in three old-growth forests with differing tephra depths. For 26 species, we calculated the frequency of plots with residuals (individuals that survived the eruption) versus re-establishment on the tephra, timing of establishment, turnover, influence of nearby conspecific plants, importance of three components of cover increase, and relationship of flowering frequency to succession. Results: Tephra depth affected species behavior. Deep tephra produced fewer residuals, a greater increase in shoot size, and more shoot turnover; favored species that established late; and allowed establishment of early seral herbs. Nearby presence of conspecifics increased permanence of first establishment and rate of plot occupancy. Most species spread significantly in deep tephra but not in shallow tephra. Among species, frequency of flowering increased with fewer residuals, later establishment, and higher turnover. Species behavior seldom differed among growth forms based on leaf longevity and vegetative spread. Conclusion: Population dynamics at the small-plot scale differed from those of the entire population. The timing and permanency of establishment and mechanism of expansion differed among species and with tephra depth. There was some consistency among species with similar habitat breadth and degree of flowering, but little consistency associated with the usual growth form classification.

An unusual eruption occurred in 1972 on the Alaid volcano island, which is the largest and the most active in the Kuril Islands. The eruption center was very close to the coast of the Sea of Okhotsk. Lava flows were discharged into the sea to build new land. The other notable features of this eruption include the generation of explosion craters, a cinder cone, and a major ash fall. The ash fall destroyed vegetation on much of the island’s area. In 2006 the affected area was investigated and the beginning regeneration of the vegetative cover was studied; as well as the island’s soils were studied for the first time. We show the scale of damage to the vegetation, the main factors that have controlled the character and degree of the damage, as well as outline some features in the recovery changes. On the whole, the vegetative cover has been destroyed or altered over an area of about 8 km2. The vegetative cover on Atlasov I. will have remained altered for a period of a few tens of years to a few hundred years (the ash fall zone), or even a few thousand years (the lava flows). In addition to this damage, the eruption expanded the island’s area, generated new ecosystems, and to some degree increased the diversity of the vegetative cover by adding seral communities to it.

Fire is a widespread natural disturbance agent in most conifer-dominated forests. In light of climate change and the effects of fire exclusion, single and repeated high-severity (stand-replacement) fires have become prominent land management issues. We studied bird communities using point counting in the Klamath-Siskiyou ecoregion of Oregon, USA at various points in time after one or two high-severity fires. Time points included 2 and 3 years after a single fire, 17 and 18 years after a single fire, 2 and 3 years after a repeat fire (15 year interval between fires), and >100 years since stand-replacement fire (mature/old-growth forest). Avian species richness did not differ significantly among habitats. Bird density was highest 17 and 18 years after fire, lowest 2 years after fire, and intermediate in repeat burns and unburned forest. Bird community composition varied significantly with habitat type (A = 0.24, P < 0.0001) with two distinct gradients in species composition relating to tree structure (live to dead) and shrub stature. Using indicator species analysis, repeat burns were characterized by shrub-nesting and ground-foraging bird species while unburned mature forests were characterized by conifer-nesting and foliage-gleaning species. Bird density was not related to snag basal area but was positively related to shrub height. Contrary to expectations, repeated high-severity fire did not reduce species richness, and bird densities were greater in repeat burns than in once-burned habitats. Broad-leaved hardwoods and shrubs appear to play a major role in structuring avian communities in the Klamath-Siskiyou region. In light of these results, extended periods of early seral broadleaf dominance and short-interval high-severity fires may be important to the conservation of avian biodiversity.

Many programs are in place to protect and restore loworder streams and riparian zones. However, information on riparian zone forests is sparse for many biogeographical regions, especially compositional and structural data that would provide useful targets for restoration. This study provides quantitative data on riparian zone composition and forest structure from three physiographic provinces of eastern United States. Data from 219 low-order (first- to fourth-order) forested reaches were arranged by three basal area (BA) categories meant to represent successional categories and variations in forest structure. Detrended correspondence analysis (DCA) was used to illustrate differences among successional categories and physiographic provinces. The DCA ordination separated stands into four physiographic subregions, based on the species composition of late-successional stands. Many early to mid-successional stands (