Functional structure of ant and termite assemblages in old growth forest,logged forest and oil palm plantation in Malaysian Borneo

Forested tropical landscapes around the world are being extensively logged and converted to agriculture, with serious consequences for biodiversity and potentially ecosystem functioning. Here we investigate associations between habitat disturbance and functional diversity of ants and termites—two numerically dominant and functionally important taxa in tropical rain forests that perform key roles in predation, decomposition, nutrient cycling and seed dispersal. We compared ant and termite occurrence and composition within standardised volumes of soil and dead wood in old growth forest, logged forest and oil palm plantation in Sabah, Malaysian Borneo. Termites occurred substantially less frequently in converted habitats than in old growth forest, whereas ant occurrences were highest in logged forest and lowest in old growth forest. All termite feeding groups had low occurrence in disturbed habitats, with soil feeders occurring even less frequently than wood feeders. Ant functional groups showed more variable associations, with some opportunist and behaviourally dominant groups being more abundant in degraded habitats. The importance of ants and termites in tropical ecosystems and such differing patterns of assemblage variation suggest that ecosystem functioning may be significantly altered in converted habitats.     

Butterfly,seedling, sapling and tree diversity and composition in a fire‐affected Bornean rainforest

Abstract: Fire‐affected forests are becoming an increasingly important component of tropical landscapes. The impact of wildfires on rainforest communities is, however, poorly understood. In this study the density, species richness and community composition of seedlings, saplings, trees and butterflies were assessed in unburned and burned forest following the 1997/98 El Niño Southern Oscillation burn event in East Kalimantan, Indonesia. More than half a year after the fires, sapling and tree densities in the burned forest were only 2.5% and 38.8%, respectively, of those in adjacent unburned forest. Rarefied species richness and Shannon's H’ were higher in unburned forest than burned forest for all groups but only significantly so for seedlings. There were no significant differences in evenness between unburned and burned forest. Matrix regression and Akaike's information criterion (AIC) revealed that the best explanatory models of similarity included both burning and the distance between sample plots indicating that both deterministic processes (related to burning) and dispersal driven stochastic processes structure post‐disturbance rainforest assemblages. Burning though explained substantially more variation in seedling assemblage structure whereas distance was a more important explanatory variable for trees and butterflies. The results indicate that butterfly assemblages in burned forest were primarily derived from adjacent unburned rainforest, exceptions being species of grass‐feeders such as Orsotriaena medus that are normally found in open, disturbed areas, whereas burned forest seedling assemblages were dominated by typical pioneer genera, such as various Macaranga species that were absent or rare in unburned forest. Tree assemblages in the burned forest were represented by a subset of fire‐resistant species, such as Eusideroxylon zwageri and remnant dominant species from the unburned forest.     

Influence of Post‐Clearing Treatment on the Recovery of Herbaceous Plant Communities in Amazonian Secondary Forests

Secondary forests are an increasingly common feature in tropical landscapes worldwide and understanding their regeneration is necessary to design effective restoration strategies. It has previously been shown that the woody species community in secondary forests can follow different successional pathways according to the nature of past human activities in the area, yet little is known about patterns of herbaceous species diversity in secondary forests with different histories of land use. We compared the diversity and abundance of herbaceous plant communities in two types of Central Amazonian secondary forests—those regenerating on pastures created by felling and burning trees and those where trees were felled only. We also tested if plant density and species richness in secondary forests are related to proximity to primary forest. In comparison with primary forest sites, forests regenerating on non‐burned habitats had lower herbaceous plant density and species richness than those on burned ones. However, species composition and abundance in non‐burned stands were more similar to those of primary forest, whereas several secondary forest specialist species were found in burned stands. In both non‐burned and burned forests, distance from the forest edge was not related to herbaceous density and species richness. Overall, our results suggest that the natural regeneration of herbaceous species in secondary tropical forests is dependent on a site's post‐clearing treatment. We recommend evaluating the land history of a site prior to developing and implementing a restoration strategy, as this will influence the biological template on which restoration efforts are overlaid.     

Decomposition of tissue baits and termite density along a gradient of human land‐use intensification in Western Kenya

Termites are important decomposers and ‘ecosystem engineers’ in tropical ecosystems. Furthermore, termite assemblages are sensitive to human land‐use intensification and often termite density and the importance of soil‐feeding termites decrease with land‐use intensification. These changes in termite assemblages may also lead to a decrease in termite‐mediated ecosystem processes (e.g. soil formation, cellulose decomposition). We compared density and functional composition of termites with cellulose removal from undisturbed primary forests to farmlands (Kakamega Forest, Western Kenya). In contrast to the expectation, we found no response of termite abundance along the gradient of land‐use intensification. However, as expected, the relative abundance of soil‐feeders decreased from primary forests to farmlands. In contrast, frequency of attack on tissue paper baits and removal of tissue showed a clear hump‐shaped relationship to land‐use intensification with high values in secondary forests. These nonconcordant patterns of density and functional composition of termite assemblages with cellulose removal by termites suggest that it may be misleading to infer changes in a process by the characteristics of the assemblage of organisms that mediate that process.     

Land use,fallow period and the recovery of a Caatinga forest

Caatinga vegetation continues to be converted into mosaics of secondary forest stands, but the affect of this process on biodiversity has not yet been examined. We used 35 regenerating and old‐growth stands of Caatinga to examine the recovery of plant assemblages subsequent to slash‐and‐burn agriculture and cattle ranching/pasture in northeastern Brazil. Plant assemblages were contrasted in terms of community structure (stem density/basal area/species richness/diversity), functional (leaf habit/reproductive traits) and taxonomic composition. Soil attributes were also examined to infer potential drivers for cross‐habitat differences. As expected, plant assemblages clearly differed across a large set of community‐level attributes, including all trait categories relative to leaf habit and reproduction (pollination syndrome/floral color, size, type). Overall, old‐growth forest stands supported distinct and more diverse assemblages at the plot and habitat level; e.g., long‐lived tree species were almost exclusively found in old‐growth forest stands. For most attributes, plant assemblages subsequent to pasture exhibited intermediate values between those exhibited by old‐growth forest and those of agriculture‐related stands. Surprisingly, soils exhibited similar fertility‐related scores across habitats. Our results indicate that: (1) sprouting/resprouting represents an important mechanism of forest regeneration; (2) assemblage‐level attributes suggest recovery at distinct rates; (3) forest regeneration implies community‐level changes in both vegetative and reproductive functional attributes, including directional changes; (4) Caatinga is not able to completely recover in a period of 15‐yr following land abandonment; and (5) historical land use affects recovery rates and successional pathways/taxonomic trajectories. Seasonally dry tropical forests may intrinsically cover a wide range of patterns relative to successional model, recovery rates and successional pathways.     

Canopy bird assemblages are less influenced by habitat age and isolation than understory bird assemblages in Neotropical secondary forest

Secondary forest habitats are increasingly recognized for their potential to conserve biodiversity in the tropics. However, the development of faunal assemblages in secondary forest systems varies according to habitat quality and species‐specific traits. In this study, we predicted that the recovery of bird assemblages is dependent on secondary forest age and level of isolation, the forest stratum examined, and the species’ traits of feeding guild and body mass. This study was undertaken in secondary forests in central Panama; spanning a chronosequence of 60‐, 90‐, and 120‐year‐old forests, and in neighboring old‐growth forest. To give equal attention to all forest strata, we employed a novel method that paired simultaneous surveys in canopy and understory. This survey method provides a more nuanced picture than ground‐based studies, which are biased toward understory assemblages. Bird reassembly varied according to both habitat age and isolation, although it was challenging to separate these effects, as the older sites were also more isolated than the younger sites. In combination, habitat age and isolation impacted understory birds more than canopy‐dwelling birds. Proportions of dietary guilds did not vary with habitat age, but were significantly different between strata. Body mass distributions were similar across forest ages for small‐bodied birds, but older forest supported more large‐bodied birds, probably due to control of poaching at these sites. Canopy assemblages were characterized by higher species richness, and greater variation in both dietary breadth and body mass, relative to understory assemblages. The results highlight that secondary forests may offer critical refugia for many bird species, particularly specialist canopy‐dwellers. However, understory bird species may be less able to adapt to novel and isolated habitats and should be the focus of conservation efforts encouraging bird colonization of secondary forests.     

Diversity and community composition of butterflies and odonates in an ENSO-induced fire affected habitat mosaic: a case study from East Kalimantan, Indonesia

Little is known about the diversity of tropical animal communities in recently fire‐affected environments. Here we assessed species richness, evenness, and community similarity of butterflies and odonates in landscapes located in unburned isolates and burned areas in a habitat mosaic that was severely affected by the 1997/98 ENSO (El Niño Southern Oscillation) event in east Kalimantan, Indonesian Borneo. In addition related community similarity to variation in geographic distance between sampling sites and the habitat/vegetation structure Species richness and evenness differed significantly among landscapes but there was no congruence between both taxa. The species richness of butterflies was, for example, highest in sites located in a very large unburned isolate whereas odonate species richness was highest in sites located in a small unburned isolate and once‐burned forest. We also found substantial variation in the habitat/vegetation structure among landscapes but this was mainly due to variation between unburned and burned landscapes and variation among burned landscapes. Both distance and environment (habitat/vegetation) contributed substantially to explaining variation in the community similarity (beta diversity) of both taxa. The contribution of the environment was, however, mainly due to variation between unburned and burned landscapes, which contained very different assemblages of both taxa. Sites located in the burned forest contained assemblages that were intermediate between assemblages from sites in unburned forest and sites from a highly degraded slash‐and‐burn area indicating that the burned forest was probably recolonised by species from these disparate environments. We, furthermore, note that in contrast to species richness (alpha diversity) the patterns of community similarity (beta diversity) were highly congruent between both taxa. These results indicate that community‐wide multivariate measures of beta diversity are more consistent among taxa and more reliable indicators of disturbance, such as ENSO‐induced burning, than univariate measures.     

Tropical soils degraded by slash‐and‐burn cultivation can be recultivated when amended with ashes and compost

In many tropical regions, slash‐and‐burn agriculture is considered as a driver of deforestation; the forest is converted into agricultural land by cutting and burning the trees. However, the fields are abandoned after few years because of yield decrease and weed invasion. Consequently, new surfaces are regularly cleared from the primary forest. We propose a reclamation strategy for abandoned fields allowing and sustaining re‐cultivation. In the dry region of south‐western Madagascar, we tested, according to a split‐plot design, an alternative selective slash‐and‐burn cultivation technique coupled with compost amendment on 30–year‐old abandoned fields. Corn plants (Zea mays L.) were grown on four different types of soil amendments: no amendment (control), compost, ashes (as in traditional slash‐and‐burn cultivation), and compost + ashes additions. Furthermore, two tree cover treatments were applied: 0% tree cover (as in traditional slash‐and‐burn cultivation) and 50% tree cover (selective slash‐and‐burn). Both corn growth and soil fertility parameters were monitored during the growing season 2015 up to final harvest. The amendment compost + ashes strongly increased corn yield, which was multiplied by 4–5 in comparison with ashes or compost alone, reaching 1.5 t/ha compared to 0.25 and 0.35 t/ha for ashes and compost, respectively. On control plots, yield was negligible as expected on these degraded soils. Structural equation modeling evidenced that compost and ashes were complementary fertilizing pathways promoting soil fertility through positive effects on soil moisture, pH, organic matter, and microbial activity. Concerning the tree cover treatment, yield was reduced on shaded plots (50% tree cover) compared to sunny plots (0% tree cover) for all soil amendments, except ashes. To conclude, our results provide empirical evidence on the potential of recultivating tropical degraded soils with compost and ashes. This would help mitigating deforestation of the primary forest by increasing lifespan of agricultural lands.     

Evolution of termite functional diversity: analysis and synthesis of local ecological and regional influences on local species richness

Aim To (1) describe termite functional diversity patterns across five tropical regions using local species richness sampling of standardized areas of habitat; (2) assess the relative importance of environmental factors operating at different spatial and temporal scales in influencing variation in species representation within feeding groups and functional taxonomic groups across the tropics; (3) achieve a synthesis to explain the observed patterns of convergence and divergence in termite functional diversity that draws on termite ecological and biogeographical evidence to‐date, as well as the latest evidence for the evolutionary and distributional history of tropical rain forests. Location Pantropical. Methods A pantropical termite species richness data set was obtained through sampling of eighty‐seven standardized local termite diversity transects from twenty‐nine locations across five tropical regions. Local‐scale, intermediate‐scale and large‐scale environmental data were collected for each transect. Standardized termite assemblage and environmental data were analysed at the levels of whole assemblages and feeding groups (using components of variance analysis) and at the level of functional taxonomic groups (using correspondence analysis and canonical correspondence analysis). Results Overall species richness of local assemblages showed a greater component of variation attributable to local habitat disturbance level than to region. However, an analysis accounting for species richness across termite feeding groups indicated a much larger component of variation attributable to region. Mean local assemblage body size also showed the greater overall significance of region compared with habitat type in influencing variation. Ordination of functional taxonomic group data revealed a primary gradient of variation corresponding to rank order of species richness within sites and to mean local species richness within regions. The latter was in the order: Africa > south America > south‐east Asia > Madagascar > Australia. This primary gradient of species richness decrease can be explained by a decrease in species richness of less dispersive functional taxonomic groups feeding on more humified food substrates such as soil. Hence, the transects from more depauperate sites/regions were dominated by more dispersive functional taxonomic groups feeding on less humified food substrates such as dead wood. Direct gradient analysis indicated that ‘region’ and other large‐scale factors were the most important in explaining patterns of local termite functional diversity followed by intermediate‐scale geographical and site variables and, finally, local‐scale ecological variables. Synthesis and main conclusions Within regions, centres of termite functional diversity lie in lowland equatorial closed canopy tropical forests. Soil feeding termite evolution further down food substrate humification gradients is therefore more likely to have depended on the long‐term presence of this habitat. Known ecological and energetic constraints upon contemporary soil feeders lend support for this hypothesis. We propose further that the anomalous distribution of termite soil feeder species richness is partly explained by their generally very poor dispersal abilities across oceans. Evolution, radiation and dispersal of soil feeder diversity appears to have been largely restricted to what are now the African and south American regions. The inter‐regional differences in contemporary local patterns of termite species richness revealed by the global data set point to the possibility of large differences in consequent ecosystem processes in apparently similar habitats on different continents.     

Termite (Insecta: Isoptera) Species Composition in a Primary Rain Forest and Agroforests in Central Amazonia

Termites play important roles in organic matter decomposition, nutrient cycling, and soil structure in tropical rain forests. When forests are replaced by agriculture, termite species richness, abundance, and function often decline. We compared the termite assemblage of a primary forest site with that of a low plant diversity, palm-based agroforest (five plant species) and a high plant diversity, home-garden agroforest (10 plant species) using a rapid biodiversity assessment protocol. In comparing the primary forest termite species composition to previously published studies, we found soil feeders and the Apicotermitinae to be more dominant than previously reported in Amazonia. Thirty percent of the species belonged to the Apicotermitinae, and an unusually high percentage (57%) of species were soil feeders. Unexpectedly, the palm-based agroforest, despite its lower plant diversity, was closer to primary forest in termite species composition, rate of species accumulation, and proportions of species in taxonomic and functional classes than was the home-garden agroforest. This suggests that particular plant attributes may better determine the termite assemblage than plant diversity alone in these agroecosystems. Unlike other agroecosystems reported in the literature, Apicotermitinae and soil feeders were proportionally more abundant in these agroforests than in primary forest. The ability of agroforests to support populations of soil feeders has a potentially positive effect on soil fertility in these agroecosystems; insomuch as feeding guild is a proxy for function, these closed-canopy agroforests may be able to sustain the same termite-mediated functions as primary forest.     

Return of Fire as a Restoration Tool: Long‐Term Effects of Burn Severity on Habitat Use by Mexican Fox Squirrels

After decades of suppression, fire is returning to forests of the western United States through wildfires and prescribed burns. These fires may aid restoration of vegetation structure and processes, which could improve conditions for wildlife species and reduce severe wildfire risk. Understanding response of wildlife species to fires is essential to forest restoration because contemporary fires may not have the same effects as historical fires. Recent fires in the Chiricahua Mountains of southeastern Arizona provided opportunity to investigate long‐term effects of burn severity on habitat selection of a native wildlife species. We surveyed burned forest for squirrel feeding sign and related vegetation characteristics to frequency of feeding sign occurrence. We used radio‐telemetry within fire‐influenced forest to determine home ranges of Mexican fox squirrels, Sciurus nayaritensis chiricahuae, and compared vegetation characteristics within home ranges to random areas available to squirrels throughout burned conifer forest. Squirrels fed in forest with open understory and closed canopy cover. Vegetation within home ranges was characterized by lower understory density, consistent with the effects of low‐severity fire, and larger trees than random locations. Our results suggest that return of low‐severity fire can help restore habitat for Mexican fox squirrels and other native wildlife species with similar habitat affiliations in forests with a historical regime of frequent, low‐severity fire. Our study contributes to an understanding of the role and impact of fire in forest ecosystems and the implications for forest restoration as fire returns to the region.     

Reptile and Amphibian Responses to Restoration of Fire‐Maintained Pine Woodlands

Fire‐maintained woodlands and savannas are important ecosystems for vertebrates in many regions of the world. These ecosystems are being restored by forest managers, but little information exists on herpetofaunal responses to this restoration in areas dominated by shortleaf pine (Pinus echinata). We compared habitat characteristics and herpetofaunal communities in restored pine woodlands to relatively unmanaged, second‐growth forests in the Ouachita Mountains of western Arkansas, USA. We found woodland restoration with periodic burning affected species differently; some species benefited, some species appeared negatively affected, but most species did not respond clearly either way. Overall reptile captures were significantly (p = 0.041) greater in pine‐woodlands than in unrestored forest; one species of snake and three species of lizards were captured more often in woodlands than unrestored forests. Among anurans, we found no significant difference in captures between woodlands and unrestored forests for any species. Among salamanders, we captured western slimy salamanders (Plethodon albagula) almost exclusively in unrestored forest, but captures of other species did not differ between the two treatments. Historically, the Ouachita region likely consisted of a mosaic that included both fire‐maintained habitats (woodlands, savannas, and prairies) and areas of denser forest on mesic sites that were less likely to burn. Consequently, landscapes that retain both open woodlands and denser, less‐intensely burned forest (in the form of unharvested greenbelts or separate stands) would likely promote and maintain a greater diversity of herpetofauna.     

Mean latitudinal range sizes of bird assemblages in six Neotropical forest chronosequences

Aim The geographical range size frequency distributions of animal and plant assemblages are among the most important factors affecting large‐scale patterns of diversity. Nonetheless, the relationship between habitat type and the range size distributions of species forming assemblages remains poorly understood. We examined how the mean latitudinal range sizes of species in Neotropical bird species assemblages shift during forest clearance and subsequent regeneration. We tested the hypothesis that bird species assemblages in early successional habitats tend to have larger latitudinal ranges than those in more mature forests. Location We considered breeding bird chronosequence data from six Neotropical forests. Results Breeding bird assemblages were found to have the species with the largest average latitudinal range sizes in cleared areas, intermediate in young secondary forests and smallest in old secondary and mature forests. Similar differences were also found when we compared congeners differing in their successional preferences. Sizes of regional ranges (within the Neotropics) did not, however, differ consistently among successional stages. The larger latitudinal (but not regional) ranges of early successional species was as a result in part of the tendency of early successional species to have ranges that extend beyond the Neotropical forest biome. Conclusions Our analysis of chronosequences suggests that as early successional habitats mature, a consistent shift from large‐ranged species towards more small ranged species occurs. Even relatively old secondary forests have bird species with larger average ranges than mature forests. As a consequence, conservation of secondary forests alone will miss many of the species most at risk of extinction and most unlikely to be conserved in other locations or biomes.     

Change in Phylogenetic Community Structure during Succession of Traditionally Managed Tropical Rainforest in Southwest China

Tropical rainforests in Southeast Asia are facing increasing and ever more intense human disturbance that often negatively affects biodiversity. The aim of this study was to determine how tree species phylogenetic diversity is affected by traditional forest management types and to understand the change in community phylogenetic structure during succession. Four types of forests with different management histories were selected for this purpose: old growth forests, understorey planted old growth forests, old secondary forests (∼200-years after slash and burn), and young secondary forests (15–50-years after slash and burn). We found that tree phylogenetic community structure changed from clustering to over-dispersion from early to late successional forests and finally became random in old-growth forest. We also found that the phylogenetic structure of the tree overstorey and understorey responded differentially to change in environmental conditions during succession. In addition, we show that slash and burn agriculture (swidden cultivation) can increase landscape level plant community evolutionary information content.     

Beta‐Diversity of Termite Assemblages Among Primary French Guiana Rain Forests

Termites are an important component of tropical rain forests, and have been included in many studies focusing on the influence of human disturbance. Their distribution among primary rain forest has, however, rarely been investigated. Here we studied the termite fauna in seven mostly undisturbed forest sites, representing several rain forest types. Overall, approximately 70 percent of species were soil‐feeders and 25 percent were wood‐feeders, the remaining 5 percent being classified here as litter‐feeders. Termite species richness did not differ significantly among sites, but sites differed in termite abundance. The palm swamp and the low forest situated on the foothills of an inselberg, hosted different termite communities to the other sites. These two sites presented a singular physiognomy suggesting that forest type is an important factor influencing species composition. We found no correlation between termite species composition and distance between sites, highlighting that at the scale of our study (about 100 km), forest sites share a similar species pool.     

Long‐term recovery of the functional community assembly and carbon pools in an African tropical forest succession

On the African continent, the population is expected to expand fourfold in the next century, which will increasingly impact the global carbon cycle and biodiversity conservation. Therefore, it is of vital importance to understand how carbon stocks and community assembly recover after slash‐and‐burn events in tropical second growth forests. We inventoried a chronosequence of 15 1‐ha plots in lowland tropical forest of the central Congo Basin and evaluated changes in aboveground and soil organic carbon stocks and in tree species diversity, functional composition, and community‐weighted functional traits with succession. We aimed to track long‐term recovery trajectories of species and carbon stocks in secondary forests, comparing 5 to 200 + year old secondary forest with reference primary forest. Along the successional gradient, the functional composition followed a trajectory from resource acquisition to resource conservation, except for nitrogen‐related leaf traits. Despite a fast, initial recovery of species diversity and functional composition, there were still important structural and carbon stock differences between old growth secondary and pristine forest, which suggests that a full recovery of secondary forests might take much longer than currently shown. As such, the aboveground carbon stocks of 200 + year old forest were only 57% of those in the pristine reference forest, which suggests a slow recovery of aboveground carbon stocks, although more research is needed to confirm this observation. The results of this study highlight the need for more in‐depth studies on forest recovery in Central Africa, to gain insight into the processes that control biodiversity and carbon stock recovery.     

Species composition of termites of the Nyika plateau forests, northern Malawi, over an altitudinal gradient

Termites were surveyed at three altitudes (Brachystegia woodland at 1676 m and 1905 m, and Juniper woodland at 2210 m) in forests within the Nyika Plateau, northern Malawi. Sampling was by a standardized 100 m transect protocol. Termite diversity was highest in the mid‐altitude site and lowest in the Juniper forest. The assemblages were dominated by soil‐feeding termites in the Termitidae subfamilies Apicotermitinae and Termitinae, and included one new soldierless Apicotermitinae genus. The structure of the assemblages was clearly due to a mixture of altitudinal and site history factors. This was especially true of the lowest altitude forest where burning and other anthropogenic disturbance factors appear to have reduced termite diversity relative to the mid‐altitude site. The Nyika plateau shows a much higher diversity at mid‐altitudes than similar SE Asian sites, probably due to the larger area of highland in Africa than in SE Asia. In addition, the clade composition of the Nyika assemblages differs completely from that found at similar altitudes in SE Asia. This preliminary study supports the hypothesis that mid‐ to high‐ altitude assemblages in both SE Asia and Africa appear to be derived from depauperated random subsets of the lowland fauna rather than from clades specifically adapted to higher altitudes.     

Do riparian forest strips in modified forest landscapes aid in conserving bat diversity?

Agricultural practices lead to losses of natural resources and biodiversity. Maintaining forests alongside streams (riparian forest strips) has been used as a mechanism to minimize the impact of clearing for agriculture on biodiversity. To test the contribution of riparian forest strips to conserve biodiversity in production landscapes, we selected bats as a biodiversity model system and examined two dimensions of diversity: taxonomic and functional. We compared bat diversity and composition in forest, with and without stream habitat, and in narrow forest riparian strips surrounded by areas cleared for agriculture. We tested the hypothesis that riparian forest strips provide potential conservation value by providing habitat and serving as movement corridors for forest bat species. Riparian forest strips maintained 75% of the bat species registered in forested habitats. We found assemblage in sites with riparian forest strips were dominated by a few species with high abundance and included several species with low abundance. Bat species assemblage was more similar between sites with streams than between those sites to forests without stream habitat. These results highlight the importance of stream habitat in predicting presence of bat species. We registered similar number of guilds between forest sites and riparian forest strips sites. Relative to matrix habitats, stream and edge habitats in riparian forest strips sites were functionally more diverse, supporting our hypothesis about the potential conservation value of riparian forest strips. Results from this study suggest that maintaining riparian forest strips within cleared areas for agricultural areas helps conserve the taxonomic and functional diversity of bats. Also, it provides basic data to evaluate the efficacy of maintaining these landscape features for mitigating impacts of agricultural development on biodiversity. However, we caution that riparian forest strips alone are not sufficient for biodiversity maintenance; their value depends on maintenance of larger forest areas in their vicinity.     

Slash Pile Burning Effects on Soil Biotic and Chemical Properties and Plant Establishment: Recommendations for Amelioration

Ponderosa pine forest restoration consists of thinning trees and reintroducing prescribed fire to reduce unnaturally high tree densities and fuel loads to restore ecosystem structure and function. A current issue in ponderosa pine restoration is what to do with the large quantity of slash that is created from thinning dense forest stands. Slash piling burning is currently the preferred method of slash removal because it allows land managers to burn large quantities of slash in a more controlled environment in comparison with broadcast burning slash. However burning slash piles is known to have adverse effects such as soil sterilization and exotic species establishment. This study investigated the effects of slash pile burning on soil biotic and chemical variables and early herbaceous succession on burned slash pile areas. Slash piles were created following tree thinning in two adjacent approximately 20‐ha ponderosa pine (Pinus ponderosa) restoration treatments in the Coconino National Forest near Flagstaff, Arizona. We selected 30 burned slash pile areas and sampled across a gradient of the burned piles for arbuscular mycorrhizal (AM) propagule densities, the soil seed bank, and soil chemical properties. In addition, we established five 1‐m² plots in each burned pile to quantify the effect of living soil (AM inoculum) and seeding amendments on early herbaceous succession in burned slash pile areas. The five treatments consisted of a control (no treatment), living soil (AM inoculum) amendment, sterilized soil (no AM inoculum) amendment, seed amendment, and a seed/soil (AM inoculum) amendment. Slash pile burning nearly eliminated populations of viable seeds and AM propagules and altered soil chemical properties. Amending scars with native seeds increased the cover of native forbs and grasses. Furthermore adding both seed and living soil more than doubled total native plant cover and decreased ruderal and exotic plant cover. These results indicate that seed/soil amendments that increase native forbs and grasses may enhance the rate of succession in burned slash pile areas by allowing these species to outcompete exotic and ruderal species also establishing at the site through natural regeneration.     

Vegetation Recovery in Slash‐Pile Scars Following Conifer Removal in a Grassland‐Restoration Experiment

A principal challenge to restoring tree‐invaded grasslands is the removal of woody biomass. Burning of slash piles to reduce woody residues from forest restoration practices generates intense, prolonged heating, with adverse effects on soils and vegetation. In this study, we examined vegetation responses to pile burning following tree removal from conifer‐invaded grasslands of the Oregon Cascades. We quantified the longevity and magnitude of fire effects by comparing ground conditions and the cover and richness of plant species in burn‐scar centers (higher‐intensity fire) and edges (lower‐intensity fire) with adjacent unburned vegetation 7 years after treatment. We interpreted patterns of recovery through the responses of species with differing growth forms, habitat affinities, and clonality. Cover of bare ground remained elevated at the centers, but not at the edges of scars; however, much of this effect was due to gopher disturbance. Total plant cover, consisting entirely of native species, was comparable in and adjacent to scars. However, richness remained depressed at the scar centers. Cover of grass, meadow, and non‐clonal species was comparable in and adjacent to scars, but cover of forb, sedge, residual forest, and clonal species was reduced at the centers. Although scar centers had a simpler community structure (fewer but more abundant species) than the adjacent vegetation, they remained free of exotics and recovered quickly, aided by the soil‐disturbing activities of gophers and the regenerative traits of native, disturbance‐adapted species. Pile burning can be a viable and efficient approach to fuel reduction in the absence of exotics.