Search

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.

Concern exists about the effects that silvicultural herbicides, past herbivory, and forest succession may have on the carrying capacity for ungulates in the vicinity of Mount St. Helens in southwest Washington. We independently evaluated the effects of both operational herbicides and ungulate herbivory on biomass and available digestible energy of forages in a chronosequence of early-succession (ES) forest stands using a retrospective, paired-site design. We distinguished between trends in biomass by classifying species as avoided (used less than available) or accepted (used equal or more than available) forages for elk based on recent research involving foraging trials of hand-raised, tractable elk in western Oregon and Washington. Herbicide application reduced biomass of accepted forages (kg/ha) for only two years, whereas the initial reduction in avoided biomass persisted throughout the 13-year ES period that we evaluated. The reduction in avoided species was not associated with an increase in accepted species, which may be related to herbivory. We observed that forest canopy closure even at 10–13 years was similar in stands treated and untreated with herbicides, suggesting herbicides did not shorten the seral window when palatable forages were abundant. Because dry matter digestibility of accepted species was generally higher than avoided species, digestible energy (DE, kcal/ha) available to elk was similar to trends in accepted and avoided biomass. An initial 2-year increase in modelled estimates of dietary DE in herbicide-treated stands in years 1–2 resulted from a rapid recovery of plants with high digestibility. In contrast to herbicide treatments, effects of ungulate herbivory on ES communities increased with stand age with a reduction of deciduous shrub height but not densities, reduced biomass of accepted but not avoided species, and reduced standing DE of accepted species outside exclosures. Despite the influence of herbicide applications, herbivory, or their interactions, nutritional resources for elk were equal or more available in ES stands than in mid- and late-succession stands, highlighting the importance of maintaining ES stands for elk in this region.

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.

Aminocyclopyrachlor (AMCP) will control many invasive broadleaf weeds, but the susceptibility of desirable forbs is not widely known. Native prairie response to AMCP was evaluated near Fargo, ND, and Felton, MN, in the Northern Great Plains. Both sites had high floristic quality prior to treatment, with 33 and 80 different species at Fargo and Felton, respectively. AMCP was applied at 140 g ha−1 in July 2014 to coincide with leafy spurge and Canada thistle treatment timing. AMCP altered the plant communities and reduced foliar cover of undesirable species, high seral forbs (undisturbed stable communities), and low seral forbs (early succession in disturbed communities) at both locations at 10 and 14 mo after treatment (MAT). AMCP reduced Canada thistle and leafy spurge in Fargo and eliminated hedge bindweed, prickly lettuce, and black medic in Felton. High seral forb foliar cover was reduced at 10 and 14 MAT from 20% to 2% and 3% in Fargo and from 19% to 1.6% and 2% in Felton, respectively. The high seral forb species birdfoot violet, white panicled aster, northern bedstraw, Canada goldenrod, purple meadowrue, and American vetch were reduced at both locations. Low seral forb cover also decreased at 10 MAT from 22% to 10% in Fargo and from 12% to 1% in Felton, respectively. By 14 MAT, low seral species in Fargo recovered to 16%, but recovery was much slower in Felton and slightly increased to 1.5%. After treatment high and low seral monocot species increased at both sites, likely due to reduced competition from susceptible species. AMCP reduced richness, evenness, and diversity at both locations at 10 and 14 MAT; therefore, floristic quality declined. A decline in diversity is generally undesirable but could have beneficial effects if invasive weeds and other undesirable species are reduced or eliminated.

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.

Following disturbances, early-seral stages of forests provide a variety of structures. Whether this variety is a short-term phenomenon or influences forest succession for several decades or even longer is not known. We tested the hypotheses that after spruce dieback caused by bark beetles, a high spatial heterogeneity of stand structures will persist within stands and among stands even in advanced early-seral stages and that species taxonomical and functional diversity measures will reflect this heterogeneity. We used a chronosequence of unmanaged forests in the Berchtesgaden National Park (Germany) consisting of mature undisturbed spruce stands (control), stands belonging to an initial early-seral stage (~3 years after disturbance) and stands in an advanced early-seral stage (~20 years after disturbance). We analysed diversity and heterogeneity of these forest stands including stand structure, species density, species composition and functional–phylogenetic diversity of vascular plants, wood-inhabiting fungi and saproxylic beetles within plots, among plots of the same successional stage and among stages. Stands of the advanced early-seral stage were characterized by a high spatial heterogeneity of structural attributes, such as crown cover, regeneration density and spatial distribution of trees. Among-plot taxonomic beta diversity was highest in the advanced early-seral stage for beetles, but lowest for fungi, while beta diversity of plants among plots remained unchanged during succession. The mosaic of successional stages initiated by bark beetles increased the gamma diversity of the study area, especially for fungi and beetles. Our findings support the hypothesis that structural heterogeneity continues for at least two decades at stand and landscape scales and that species turnover among successional stages is a major mechanism for gamma diversity in forests after bark beetle disturbance.

The first year of secondary succession in a harvested Eucalyptus camaldulensis plantation near Maragamuwa village, Naula, was examined to see the possible effect of distance from the adjacent relatively undisturbed mature forest on the form and composition of natural regeneration after removal of eucalypts. Composition, relative densities and absolute abundance were examined in cleared 40, 20 × 20 m2 quadrats placed in eight 1 ha blocks in two types of locations: harvested eucalypt plantation away from the natural forest (MP) and harvested blocks next to the natural forest (MT), and compared with 20 similar sized quadrats sampled in the adjacent mature forest (NF). Relative density values for MT and MP were compared with the adjacent NF using Kruskal-Wallis and Mann-Whitney U tests. A total of 11,207 individuals from 77 species were recorded per hectare in MP, while 11,658 individuals/ha from 61 species were recorded from MT and 5,925 individuals/ha from 39 species in NF. Relative densities of seedlings in MP and MT were significantly different from NF (p p>0.05). Most individuals in MP and MT were 1-100 cm tall. Species composition suggests the basis for seral succession, with the cleared and distant MP plots having most non-forest species, and a high abundance per species compared with the MT plots adjacent to the mature forest. Natural forest plots had fewer individuals in each family or species, and a far lower density of the lianas typical of the first stages of colonization. In the first year of succession, there were indications of a distance effect in blocks adjacent to forest sites.

Lepidoptera (moths and butterflies) are important components of forest ecosystems; they affect tree growth and influence nutrient cycling as caterpillars, provide food for higher trophic levels as caterpillars and adults, and are pollinators as adults. Here, we report on and compare the results of two long-term studies of the effects of logging on Lepidoptera in oak hickory forests. In one study, the Missouri Ozark Forest Ecosystem Project (MOFEP), caterpillars were used as response taxa. Sampling via observation without removal focused on larvae found on leaves of two dominant tree species, Quercus alba and Q. velutina , in alternative harvest regimes. In a second, the Hardwood Ecosystem Experiment of Indiana (HEE), we examined the response of adults to alternative harvest levels by sampling with blacklighting. Caterpillar sampling in MOFEP and in an associated chronosequence revealed that clearcutting decreases numbers and diversity of Lepidoptera, year effects were as important in influencing caterpillar assemblages as the harvest per se , and that species richness of caterpillars continued to increase each year post-harvest. When using adult moths as response taxa, species composition was resilient to timber harvest under shelterwood management, recovering to the near original condition three years post treatment. Communities in patch cut or clear cut stands were slower to recover, and appeared to develop novel communities relative to their pre-harvest condition. A late spring frost decreased abundance and species richness of caterpillars, while a severe drought impacted adult lepidopterans, depressing species richness in patch cut stands to a greater degree than in control or shelterwood cut stands. Together, these results demonstrate that Lepidoptera communities in oak-history forests respond immediately to logging due to changes in host plant availability, but may also be impacted many years subsequent due to stochastic year effects and seral changes in forest structure and composition.

Landslides have a direct impact in the ecosystems dynamics being considered one of the main vegetation perturbation processes. Our objective is to determine the relation between vegetation cover evolution and time period after landslide disturbance, and therefore to assess the potential use of vegetation evolution within landslide areas as temporal bioindicators of landslide activity, in order to determine landslide relative age. Four rotational slides of known relative age, located in the Grande da Pipa River basin (Arruda dos Vinhos, Portugal) were selected. The methodology includes four main steps: (1) to identify the flora and vegetation differences between the main landslide sectors (scarp, body, foot); (2) to find out if the differences in floristic composition and vegetation structure are reflected in the succession process; (3) to find out if the succession process has produced different seral stages along the longitudinal gradients; (4) to compare the succession process in landslide affected areas with the undisturbed adjacent areas. The data points towards a slow evolution of the vegetation in the period following the disturbance, being necessary long periods for the perturbed area reach vegetation characteristics similar to the ones of the unperturbed areas. The progressive succession is rapid in the foot, slow in the body and extremely slow in the scarp. The presence of orchids in the body may be considered as an age bioindicator of more than 15 years since landslide disturbance. In the case of the older landslide (> 50 years), it corresponds to the evolved stage close to the potential natural vegetation.

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.

High-severity fire creates patches of complex early seral forest (CESF) in mixed-severity fire complexes of the western USA. Some managers and researchers have expressed concerns that large high-severity patches are increasing and could adversely impact old forest extent or lead to type conversions. We used GIS databases for vegetation and fire severity to investigate trends in large (&gt, 400 ha) CESF patches in frequent-fire forests of the western USA, analyzing four equal time periods from 1984 to 2015. We detected a significant increase in the total area of large patches relative to the first time period only (1984&ndash, 1991), but no significant upward trend since the early 1990s. There was no significant trend in the size of large CESF patches between 1984 and 2015. Fire rotation intervals for large CESF patches ranged from ~12 centuries to over 4000 years, depending on the region. Large CESF patches were highly heterogeneous, internally creating ample opportunities for fire-mediated biodiversity. Interior patch areas far removed from the nearest low/moderate-severity edges comprised a minor portion of high-severity patches but may be ecologically important in creating pockets of open forest. There was ample historical evidence of large CESF patches but no evidence of increases that might indicate a current risk of ecosystem-type shifts.

Ponderosa pine occurs on a great variety of landforms, soil types, and climatic regimes both in pure and mixed stands which dominate a vast array of understory plants. Several investigators in the western United States and southwestern Canada have reported cattle abortions resulting from ingestion of pine needles. The North Plateau race of ponderosa pine occurs in a climax formation in the lower elevations of forest development on the east slopes of the Cascade Mountains. H. A. Fowells summarized the vast array of soils, landforms, and climates which determine the habitats occupied by ponderosa pine. Ponderosa pine most frequently regenerates following disturbance by fire, logging, insect or disease outbreaks, or heavy grazing. Timber harvest and prescribed burning can increase forage for cattle and wildlife in both seral and climax ponderosa pine communities, depending on understory plant composition, range condition, fire effects, and site.

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.

Species that are primarily seral may form stable (self-sustaining) communities under certain disturbance regimes or environmental conditions, yet such populations may also be particularly vulnerable to ecological change. Aspen (Populus spp.) are generally considered seral throughout the Northern Hemisphere, including P. tremuloides, the most widely distributed tree species in North America. Recent declines in aspen populations have occurred, especially along drought-sensitive margins of its range and where fire exclusion and herbivory have promoted community transition. However, aspen also forms stable stands, and examination of the mechanisms that influence persistence can offer conservation insights, especially where populations are vulnerable to changing climate or altered disturbance dynamics. We sampled tree age and stand characteristics of isolated aspen forests in the arid Great Basin (USA) to determine if (1) aspen communities are more fire-dependent and seral or fire-independent and stable; (2) ungulate browsing inhibits aspen stability; and (3) temporal patterns of vegetative reproduction (i.e., ramet establishment or "suckering") are correlated with climate. Aspen size and age class densities strongly fit negative exponential distributions, whether grouped geographically or by functional type, suggesting landscape-scale persistence. Continuous age distributions and high proportions of recruitment-sized to overstory trees suggest stability at stand scales, with exceptions including stands with higher browsing pressure. Few stands had evidence of fire, and relationships between dead tree size and variability in live tree size suggest a lack of fire dependency. Several 5-yr averaged climate variables and one sea surface temperature index were correlated with aspen ramet establishment densities over time, with strongest relationships occurring ~5 yr prior to establishment year, often followed by inverse relationships ~1 yr after. Indeed, aspen establishment density for a recent 41-yr period was reliably reconstructed using antecedent climate conditions derived from a single drought index. Temporally synchronized aspen ramet establishment across the study region may be due to climate-driven storage of nonstructural carbohydrate reserves in clonal root systems later used for regeneration. Complex regeneration dynamics of these self-sustaining aspen stands, especially sensitivity to climate variability, suggest they may serve as harbingers of ecological change in the arid Great Basin and in other aspen populations near their range margin.

Understanding how invertebrates respond to disturbance is important to maintaining biodiversity. In western Canadian boreal forests, anthropogenic linear corridors associated with energy exploration are a pervasive disturbance that affect many species. Trees and large shrubs are removed in a grid of narrow corridors, but the understory vegetation is generally maintained, mimicking early seral conditions. Little is known about how bees, an important group of pollinators, respond to linear corridors, with their response having important implications for plant-pollinator communities. Here, we investigated how bee abundance, diversity, species composition, and movement respond to these anthropogenic linear corridors, locally known as seismic lines. We compared bee abundance and diversity from pan traps on seismic lines (6 – 12 m wide) to traps placed 50 m into the adjacent forest interior, across 12 replicated sites. Malaise traps were used to measure bee movements on seismic lines relative to paired interior forests, but also with respect to flight direction relative to the orientation of seismic lines. Abundance and richness of bees were 3-times and 1.5-times higher, respectively, on seismic lines compared to the forest interior, with significant differences in species composition. Bees were more than twice as abundant and diverse in malaise traps that caught bees flying along seismic lines than any other combination of trap orientation and location. These results demonstrate that narrow anthropogenic linear corridors are locally increasing bee abundance and diversity in boreal forests, as well as use of these lines for movement. These results have major implications for boreal forest plant-pollinator communities.

Subalpine coniferous forests are adapted to cycles of fire and successional development, but increasing fire frequency and severity are altering historical stand structure, composition, and plant diversity. For instance, conifer regeneration has become increasingly variable as a result of prolonged aridity following fire, but the potential cascading effects on understory community development remain virtually unexplored. We used a natural experiment to investigate the relationships among understory plant succession, soil moisture regime, and variable tree canopy development over 30 years following the 1988 fires in the Greater Yellowstone Ecosystem, U.S.A. In 1990, at each of two study areas, plots were established in different site types defined by burn status (burned or unburned) and soil moisture regime (mesic or xeric), determined using biophysical indicators. We asked: (1) Are differences in soil moisture regime associated with differences in understory community composition (species richness, diversity, and functional group representation) during the first three decades after fire? (2) Does the relationship between soil moisture regime and community composition change over time as subcanopy (height >137 cm) tree densities increase? We confirmed our original designations of soil moisture regime using in situ measurements of soil moisture. Over the first decade of succession, species richness and diversity were lower in xeric-burned than in mesic-burned plots. Nearly 30 years after fire at the south-aspect study area, where subcanopy tree densities were low, seral understories diverged by soil moisture regime. There, graminoid cover was 23-fold higher, and forb cover was 3-fold lower, in xeric-burned than in mesic-burned plots. In contrast, in the mixed aspect study area, subcanopy tree densities were markedly higher. There, the understory did not vary by soil moisture regime, converging successionally and becoming more similar to unburned forest communities. Our results suggest that site-specific soil moisture regimes structure the early trajectory of post-fire understory recovery, but the relationship diminishes as tree canopies develop over time. However, under a warming climate, variable tree canopy development may compound increasing aridity, particularly on xeric sites, resulting in decreases in plant diversity and forb cover, increases in graminoid cover, and the potential for altered successional dynamics.

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 (

Spatially explicit modeling of recovering forest structure within two years following wildfire disturbance has not been attempted, yet such knowledge is critical for determining successional pathways. We used remote sensing and field data, along with digital climate and terrain data, to model and map early-seral aspen structure and vegetation species richness following wildfire. Richness was the strongest model ( rmse = 2.47 species, Adj. R 2 = 0.60), followed by aspen stem diameter, basal area ( ba ), height, density, and percent cover (Adj. R 2 range = 0.22 to 0.53). Effects of pre-fire aspen ba and fire severity on post-fire aspen structure and richness were analyzed. Post-fire recovery attributes were not significantly related to fire severity, while all but percent cover and richness were sensitive to pre-fire aspen ba (Adj. R 2 range = 0.12 to 0.33, p

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.

This study provides an analysis of vegetation and environmental relationships as well as diversity patterns in sand dunes and gravel desert plains of northern Badrud, Iran. A total of 63 species representing 49 genera and 15 families were recorded. The largest families were Asteraceae (22.2 %) and Chenopodiaceae (19.0 %). Therophytes (66.67 %) were the dominant life form. Chronological analysis showed 57.14 % Irano-Turani elements. Data from 60 1.5 2 m² quadrats, selected systematically randomized along three transects, were collected. Both two-way indicator species analysis (TWINSPAN) and cluster analysis using Ward’s method resulted in the recognition of three communities: an Artemisia sieberi community in the center plain with a Shannon-Wiener diversity index of 0.3, a Stipagrostis plumosa - Schismus arabicus community on the lower sand dunes with a Shannon-Wiener diversity index of 0.7, and a Haloxylon ammodendron community on the higher sand dunes with a Shannon-Wiener diversity index of 0.2. Detrended correspondence analysis (DCA), non-metric multidimensional scaling (NMDS), and multi-response permutation procedure (MRPP), confirmed the separation of TWINSPAN groups as well as the heterogeneity of the Artemisia sieberi - Schismus arabicus community, suggesting a distinct group with Artemisia sieberi and Schismus arabicus as the dominant species. Vegetation environmental analysis by means of multivariate techniques of principal component analysis (PCA) and canonical correspondence analysis (CCA) indicated that very coarse gravel has a strong negative effect on diversity and a negative effect on species cover percentage. Bare ground showed a highly positive effect on diversity variables. Soil analysis suggests final seral stages of succession towards severe desertification.

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.

Tree mortality is an important demographic process and primary driver of forest dynamics, yet there are relatively few plot-based studies that explicitly quantify mortality and compare the relative contribution of endogenous and exogenous disturbances at regional scales. We used repeated observations on 289,390 trees in 3673 1 ha plots on U.S. Forest Service lands in Oregon and Washington to compare distributions of mortality rates among natural disturbances and vegetation zones from the mid-1990s to mid-2000s, a period characterized by drought, insect outbreaks, and large wildfires. Endogenous disturbances (e.g. pathogens, insects) were pervasive but operated at relatively low levels of mortality ( 1%/yr in over half of the plots in late and old-growth stages corroborate previous findings of elevated mortality during the same period and indicate the potential for pervasive structural change across all vegetation zones. Partial- and stand-replacing fire were associated with most mortality, but affected a relatively small proportion of dry vegetation zones (3.1–7.1% and 2.1–5.1%, respectively). These disturbances have likely affected regional biodiversity through the creation of early seral habitat, increased within-stand heterogeneity, and restored some aspects of historical fire regimes, but there is a need to better understand corresponding structural and compositional changes. We demonstrate the variability in the drivers, magnitude, and extent of mortality across a biophysically diverse region and highlight the need to incorporate and characterize the effects of mortality at intermediate levels to develop a more comprehensive understanding of regional forest dynamics.

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.

Questions(1) Do 17 seres studied proceed towards corresponding potential natural vegetation; (2) what are the similarities between seral and potential natural vegetation, and is it possible to estimate how long it takes to reach potential natural vegetation; and (3) do primary and secondary seres differ? LocationExtracted peatlands, corridors of the former iron curtain, artificial fishpond islands and barriers, sedimentary basins, various spoil heaps after mining, various stone quarries, forest clearings, burned-down forests, road verges, sand and gravel-sand pits, river gravel bars and abandoned arable fields located in various parts of the Czech Republic. MethodsSeral stages were sampled by phytosociological releves (2602). The following categories of successional age were considered: early (1-10yrs), intermediate (11-25yrs) and late (>25yrs). Phytosociological releves (386) representing corresponding potential natural vegetation were extracted from the National Phytosociological Database. DCA and CCA ordinations were performed to compare the pattern of seral stages with potential natural vegetation and between primary and secondary seres. Dissimilarity between seral stages of primary and secondary successions and the corresponding potential natural vegetation was further assessed using the Bray-Curtis dissimilarity measure. Extrapolation was performed to estimate when the seres will reach the stage corresponding to potential natural vegetation. ResultsThe ordination showed that successions proceeded towards the corresponding potential natural vegetation and reflected substrate pH, site moisture and successional age. The estimated average time needed to reach potential natural vegetation was about 180yrs for primary successions and about 260yrs for secondary successions, considering presence-absence species data, and 200 and 250yrs, respectively, considering cover data. All species recorded in potential natural vegetation (421) were also recorded in seral vegetation. ConclusionsIn the general view across the high number of seres spread over the whole country, successions advanced in the direction of the corresponding potential natural vegetation. The extrapolated recovery of potential natural vegetation is faster in primary seres than in secondary ones, and seres sooner resemble the corresponding potential natural vegetation in species composition than in vegetation structure.

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.

Complex early-seral forests support biological legacies and unique understory vegetation (grasses, forbs, shrubs, juvenile trees) important to wildlife and ecosystem functioning. Intensive management in early-seral forest and other stages could reduce understory plant diversity and homogenize community compositions. Furthermore, the relative effects of management regime may vary at different stages of forest development. To what extent do taxonomic, functional and phylogenetic diversity vary by seral stage and/or ownership (a proxy for management regime) after accounting for climatic variation? For 2224 plant species sampled systematically at 16,330 sites in sixteen Plant Association Zones (PAZs) of Washington, Oregon and California, we estimated taxonomic, functional and phylogenetic diversity (both alpha = richness and beta = heterogeneity measures). Seral stage was inferred using forest structural metrics. Permutational multivariate analyses tested the relative effects of seral stage and ownership type. Across PAZs, a common motif emerged: low diversity in sparse, untreed stages indicated an accumulation period after stand-replacing disturbances, followed immediately by peak diversity in early sapling stages, after which gradually declining diversity coincided with the loss of shade-intolerant species during stand development and canopy closure. Departures from this motif tended to be in climatically less-permissive locations. More of the variation in diversity was explained by seral stage than ownership type (and their interactions were seldom significant). Discriminating the nuanced effects of different management regimes will require context-dependent proxies other than ownership. Identifying generalities in vegetation dynamics—and departures from those generalities—can help balance ecological and social objectives in rapidly changing forest landscapes.

Wildfire is an important natural disturbance in western North American forests and has been increasing in prevalence and severity in recent decades. Post-fire salvage logging is a common practice, however, the impacts of salvage logging on wildlife are poorly understood. We studied populations of snowshoe hares (Lepus americanus) and red squirrels (Tamiasciurus hudsonicus) in a post-fire and salvage-logged interior Douglas fir (Pseudotsuga menziesii) forest on the Chilcotin Plateau, British Columbia, Canada. Snowshoe hare densities were low, but densities were highest in 8–9-year-old regenerating post-fire forests. Hares were mostly absent from 1 to 2-year-old post-fire forests. Salvage-logged areas were not used by snowshoe hares. Red squirrel detections were highest in mature forests, and squirrels were not present in post-fire salvage-logged habitat. Post-fire salvage logging removed live canopy trees required by both snowshoe hares and red squirrels. The large scale and intensity of post-fire salvage logging removes important regenerating post-fire habitat and has detrimental impacts on these important prey species, likely leading to consequences for avian and mammalian predators.

Once dominant but now largely excluded from eastern North America, open forests of savannas to woodlands occupy the ecosystem gradient between grasslands and closed forests. These fire-maintained systems differ in structure, processes, and species from closed canopy, succession-driven forests that currently dominate this region. In functional open forest ecosystems, frequent, low to mixed severity and intensity surface fires limit tree regeneration, depending on factors such as overstory tree density, resulting in relatively stable structure where overstory trees co-exist with a largely herbaceous understory. Reduced and spatially variable tree densities in open forests result in unique environmental conditions and function. Trees in open forests typically represent a small fraction of the biodiversity, which instead resides in the rich herbaceous ground layer. Rather than being constrained by overstory disturbances, succession, and biological legacies, the permanently open structure and herbaceous communities of open forests support invertebrate and vertebrate species throughout their lifetimes. Transition from open to closed forests across most of eastern North America during the past century produced a “new normal,” in which excluded open forests remain largely unrecognized at considerable conservation costs, particularly loss of key processes and wildlife species associated with a matrix of co-dominant tree and herbaceous layers. Management for open forests emphasizes the understory herbaceous plant community, similar to ephemeral seral stages of successional forest, rather than tree regeneration to produce an alternative outcome in structure, function, and support for biodiversity.

Retention forestry aims to maintain structural and functional continuity in managed stands. While short-term benefits to forest dwellers are well documented, few studies have followed patterns over decades to assess whether benefits continue. Initiated in 1992, the Date Creek Research Forest in northwest BC includes four replicates of four retention levels: 0% (clearcut), 40%, 70% and 100% (unharvested control). These ~20-hectare stands, with retention designed to mimic typical insect and wind disturbance, are now entering the canopy closure seral stage. We followed breeding bird community dynamics over 25 years (pre-harvest and 24 years post-harvest). Given relatively consistent landscape conditions over time, we focused on stand-level changes in bird community composition and species abundance. Community similarity to controls decreased as retention decreased; communities changed over time, with those in clearcuts changing most. Patterns in species abundance varied with habitat preference. Conifer-forest species declined immediately after harvest, with some responding linearly to retention level while others responded similarly to 40%, 70% and 100% treatments; Pacific Slope Flycatcher, Pacific Wren and Brown Creeper remained significantly less abundant in some treatments by year 24. Open-habitat and generalist species increased most in clearcut and somewhat in 40% retention stands, with generalists taking advantage of the increased heterogeneity immediately and open-habitat species colonizing by year 10; some of these species, particularly shrub specialists, remained at high abundance in harvested stands in year 24. Mixed-forest species reached their highest abundance at 40% retention in year 2 and 10, and dropped to control levels by year 24. Although conifer-forest, open-habitat and generalist species treated retention stands as intermediate between clearcuts and controls, mixed-forest species perceived them as a different, preferred habitat for the first decade. We conclude first that most forest birds do not discriminate between 70% retention stands and unharvested forest, confirming strategies in the region to maintain biodiversity in landscape corridors, second that aggregated 40% patch retention partially or fully mitigates impacts for conifer-forest birds, and provides new habitat for mixed-forest and open-habitat species, and third that bird communities are still changing after 24 years as these stands enter canopy closure.

The San Bernardino kangaroo rat (Dipodomys merriami parvus) is a federally listed endangered species endemic to Southern California and limited to three remaining populations. Its native habitat of alluvial fan sage scrub faces many anthropogenic threats, including urban and agricultural development, and the resulting flood control and fire suppression. With the loss of natural processes such as scouring or burning from floods and fires, the mosaic of seral stages across the landscape has shifted to dense vegetation, and active restoration may be necessary to provide suitable habitat for the San Bernardino kangaroo rat. Species distribution modeling using the partitioned Mahalanobis distance method on all occurrence points collected in the past 16 years revealed that alluvial scrub cover and fluvent soils were most strongly associated with San Bernardino kangaroo rat occupancy. Through surveys at 14 locations across the species’ range, we identified non-native grass cover, shrub cover, bare ground and sandy soils as microhabitat features related to San Bernardino kangaroo rat abundance. We also calculated the optimal range of cover for each habitat type that was correlated with higher kangaroo rat abundance. The results of this multiple-model approach can be used by the agencies to assess the value of conserved habitat, set targets for microhabitat enhancement to facilitate population growth and expansion, or identify receiver sites should translocation be required for recovery. This work lays the foundation for more coordinated and strategic restoration efforts, given the compressed and rigid timelines of development projects that continue to impact remaining San Bernardino kangaroo rat populations. Keywords: Species distribution modeling, Habitat suitability, Translocation, Heteromyid, Mahalanobis, Kangaroo rat

Dystrophic lakes undergo natural disharmonic succession, in the course of which an increasingly complex and diverse, mosaic-like pattern of habitats evolves. In the final seral stage, the most important role is played by a spreading Sphagnum mat, which gradually reduces the lake’s open water surface area. Long-term transformations in the primary structure of lakes cause changes in the structure of lake-dwelling fauna assemblages. Knowledge of the succession mechanisms in lake fauna is essential for proper lake management. The use of fractal concepts helps to explain the character of fauna in relation to other aspects of the changing complexity of habitats. Our 12-year-long study into the succession of water beetles has covered habitats of 40 selected lakes which are diverse in terms of the fractal dimension. The taxonomic diversity and density of lake beetles increase parallel to an increase in the fractal dimension. An in-depth analysis of the fractal structure proved to be helpful in explaining the directional changes in fauna induced by the natural succession of lakes. Negative correlations appear between the body size and abundance. An increase in the density of beetles within the higher dimension fractals is counterbalanced by a change in the size of individual organisms. As a result, the biomass is constant, regardless of the fractal dimension.

We sought to understand the relationship between the seed bank and vegetation in abandoned rice paddies in South Korea, in order to guide management of these sites. We investigated the floristic composition and species richness of the soil seed bank and ground vegetation in former paddies along three seral gradients (wet meadow, young forest, and mature forest) in Gwangneung Forest Biosphere Reserve. Seed bank samples contained 59 species, of which the dominant families were Cyperaceae, Gramineae, and Polygonaceae. Species richness and seedling density (59 taxa and 19,121 germinants from all samples) were high. Carex spp. (11, 921 germinants) were the dominant taxa. The species composition in the seed bank changed gradually as the land transitioned from wet meadow to mature forest. Sorensen’s index of similarity between above- and below-ground vegetation was 29.3% for wet meadow, 10.8% for young forest, and 2.1% for mature forest. Germinant density also declined, with 10, 256 germinants for wet meadow, 6445 germinants for young forest, and 2420 germinants for mature forest. Changes in aboveground environment and life history traits such as amphicarpic plants, likely affect the composition of soil seed bank species. Abandoned paddy fields may be good sites for restoration of wetland forest and conservation of wetland habitat. Some intervention may be required to promote the recovery of a natural species assemblage.

Land management practices often directly alter vegetation structure and composition, but the degree to which ecological processes such as herbivory interact with management to influence biodiversity is less well understood. We hypothesized that large herbivores compound the effects of intensive forest management on early seral plant communities and plantation establishment (i.e., tree survival and growth), and the degree of such effects is dependent on the intensity of management practices. We established 225-m2 wild-ungulate (deer and elk) exclosures, nested within a manipulated gradient of management intensity (no-herbicide control, light herbicide, moderate herbicide, and intensive herbicide treatments), replicated at the scale of whole harvest units (10-19 ha). Vegetation structure, composition, and crop-tree responses to herbivory varied across the gradient of herbicide application during the first two years of stand establishment, with herbivory effects most evident at light and moderate herbicide treatments. In the moderate herbicide treatment, which approximates management applied to >2.5 million hectares in the Pacific Northwest, United States, foraging by deer and elk resulted in simplified, low-cover plant communities more closely resembling the intensive herbicide treatment. Herbivory further suppressed the growth of competing vegetation in the light herbicide treatment, improving crop-tree survival, and providing early evidence of an ecosystem service. By changing community composition and vegetation structure, intensive forest management alters foraging selectivity and subsequent plant-herbivore interactions; initial shifts in early seral communities are likely to influence understory plant communities and tree growth in later stages of forest development.

Fire and seral vegetation succession are known to influence the distribution and abundance of a wide range of arid and semi-arid mammal species. In Triodia hummock grasslands, the gradual increase in Triodia cover after fire is a significant factor influencing mammal distribution and abundance. However, the height of fire-adapted hummock grass species is often ignored during habitat preference studies despite the fact that taller hummocks are likely to have improved insulation properties and greater protection from predators. We tested the relative importance of a range of Triodia habitat characteristics in determining the distribution and abundance of a fire-adapted mammal inhabiting Triodia mallee dune fields in semi-arid Australia. We sampled 77 sites and collected information on habitat attributes including Triodia cover, height and time since fire. The 90th percentile Triodia height (>400 mm) was the most reliable predictor of sandhill dunnart abundance, and breeding, inferred through the presence of subadults. The presence of adult sandhill dunnarts was best explained by Triodia cover, increasing when cover exceeded 25%. We suggest that while Triodia cover may be an important variable for predicting the presence of adult sandhill dunnarts, the height of Triodia is important for breeding, when tall Triodia are possibly sought for nesting sites. These Triodia height and cover requirements were not recorded at sites until at least 10 years post fire but the relationship between fire and Triodia cover and height was inconsistent; after 20 years Triodia cover declined with increasing fire age while the 90th percentile Triodia height remained relatively constant. This incongruence may explain why the presence of sandhill dunnarts appears more constrained by a minimum rather than maximum time since fire and could help explain patterns of post-fire distribution in other arid zone mammals. Importantly, the 90th percentile Triodia height highlighted the possible significance of scattered, tall Triodia hummocks for arid zone fossorial mammals.

This study was carried out on the Vidlič Mountain, eastern Serbia. The herb layer was surveyed in permanent plots on two localities: in a naturally regenerated beech forest and in a Douglas-fir plantation, in spring, summer and autumn 2011, 2012 and 2013. Air temperature, air humidity and soil moisture were measured. Species richness, Shannon’s diversity index and Pielou’s evenness index were calculated for each plot. Comparison of the abundances of species common to both forest stands was done using the Mann-Whitney U-test. The compositional gradient of the species data was examined using detrended correspondence analysis (DCA), and the species-environment relationship was analyzed by canonical correspondence analysis (CCA). Soil moisture and the total herb cover significantly differed in the naturally regenerated beech forest and Douglas-fir plantation. Floristic similarity between the surveyed forest stands was 28.12%. Although the dominant canopy species is known to be the strongest predictor of the herb layer, the model that includes all of the analyzed environmental factors explains the largest amount of the species variability. The species best fitted to this model are Dryopteris filix-mas, Galium odoratum, Pulmonaria officinalis, Sanicula europaea, Pteridium aquilinum and Rubus caesius. The analyzed forest stands are examples of two different post-disturbance regeneration strategies. Having in mind the limitations of this study, we can conclude that the naturally regenerated beech forest recovers faster: its herbaceous layer indicated nearly natural conditions, with only a few pioneer and disturbance-tolerant species. The herb layer in the Douglas-fir stand is still in the early seral stage, i.e. establishment. [Projekat Ministarstva nauke Republike Srbije, br. III43002: Bio-sensing technologies and global systems for the continual research and integrative ecosystem management]

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

The succession in areas once vegetated before the disturbance to a forest as climax community is called secondary succession. Secondary succession is influenced by soil type and the vegetation that invades the community. During the literature survey we found that the cropping areas are abandoned in different parts of the world and the fallows left are under secondary succession. There the socio-economy of the people has been found to affect the succession. Species diversity, species richness, rate of replacement and the soil type etc. have been studied by succession researchers. Succession study has also been carried out by using the tools like remote sensing, geographical information system etc.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 166-176

Questions How does performance of a native early seral seed mix during early life stages compare to that of a late seral mix when seeded with Bromus tectorum or Taeniatherum caput-medusae? Does either mix reduce survival of exotic annual grasses during early life stages, and does this effect differ with soil type? Is exotic performance stronger in one soil type, and does native performance when growing with exotics differ between soil types as a result of exotic preference? Location University of Nevada Agricultural Research Station, Reno, NV, US. Methods We compared seedling emergence and early survival (Nov through May) of two native seed mixes, each composed of grass, forb and shrub functional groups, when growing with B. tectorum or T. caput-medusae in soils of contrasting texture (sandy loam and clay loam). Natives were also seeded without exotics. Performance of an early seral mix was compared with that of a late seral mix representative of species commonly used in Great Basin restoration. Results Comparing emergence and survival probabilities, early seral natives generally outperformed late seral natives when growing with exotics and had earlier emergence timing, although results differed among functional groups and soil types. In contrast, survival probabilities did not differ between the early and late seral mixes when growing without exotics. Within each seed mix, native grasses exhibited the highest emergence probabilities of the functional groups. Natives did not suppress exotics in early life stages. Performance of B. tectorum was higher on sandy loam, while T. caput-medusae was highly successful in both soil types. Performance of native functional groups differed by soil type when growing with exotics but did not differ when growing without exotics. Survival of native grasses, in particular, was generally higher on sandy loam when growing with exotics. Conclusions Findings suggest that the use of early seral natives in areas invaded by exotic annual grasses may improve early seedling survival in the Great Basin, in comparison to the use of later seral species in traditional seed mixes. Variation in native performance in the two soil types may be helpful in tailoring seed mixes to different sites.

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.