Untangling the roles of fire,grazing and rainfall on small mammal communities in grassland ecosystems

In grassland systems across the globe, ecologists have been attempting to understand the complex role of fire, grazing and rainfall in creating habitat heterogeneity and the consequences of anthropogenic control of these factors on ecosystem integrity and functioning. Using a South African grassland ecosystem as a model, we investigated the impact of fire and grazing pressure on small mammal communities during three differing periods of a rainfall cycle. Over 2 years, 15,203 trap nights revealed 1598 captures of 11 species (nine rodents, one macroscelid and one insectivore). Results highlighted the importance of the interplay between factors and showed that the role of fire, grazing and rainfall in determining small mammal abundance was species-dependant. While no two species were affected by the same environmental variables, grass cover or height was important to 56% of species. Considered independently, high rainfall had a positive influence on small mammal abundance and diversity, although the lag period in population response was species-specific. High grazing negatively affected overall abundance, but specifically in Mastomys coucha; fire alone had little immediate impact on small mammal diversity. Six months after the fire, vegetation cover had recovered to similar levels as unburned areas, although small mammal diversity and richness were higher in burned areas than unburned areas. Grazing levels influenced the rate of vegetation recovery. In conclusion, low-level grazing and burning can help to maintain small mammal biodiversity, if conducted under appropriate rainfall levels. A too high grazing pressure, combined with fire, and/or fire conducted under drought conditions can have a negative impact on small mammal biodiversity. To maintain small mammal diversity in grassland ecosystems, the combined effects of the previous year’s rainfall and existing population level as well as the inhibition of vegetation recovery via grazing pressure need to be taken into consideration before fire management is applied. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Is shadier better? The effect of agroforestry management on small mammal diversity

Agroforestry systems play fundamental roles for wildlife conservation, but are prone to disturbances from management practices aiming at increasing local productivity. This work investigates the small mammal assemblages present in cacao agroforests, which differ in shade tree density. We tested the prediction that higher tree density increases shade level, analyzed how some environmental variables important for small mammals (vegetation complexity, tree basal area, and invertebrate biomass) vary across the shade level gradient, and how the assemblages respond to these variations. We also tested the effect of the environmental variables on the abundance of the three most common species: Rhipidomys mastacalis, Hylaeamys seuanezi, and Marmosa murina. We captured 651 individuals belonging to 18 species. A positive relationship was observed between an abundance of non-forest specialists and tree basal area, while species diversity within this group showed positive association with vegetation complexity. Assemblage structure (described by a matrix of species abundance per site) was not affected by our environmental variables, but R. mastacalis was more abundant in sites with lower vegetation complexity. Higher shade levels in cacao agroforest tended to occur in sites with greater tree basal area, which was not a good predictor of small mammal diversity. This suggests that environmental management to reduce shade with the purpose of increasing cacao productivity is not necessarily negative for small mammal conservation. Species diversity was favored by structurally complex systems, a possible response to greater niche diversity.     

Cape ground squirrels as ecosystem engineers: modifying habitat for plants,small mammals and beetles in Namib Desert grasslands

Burrowing and foraging of semi‐fossorial rodents can affect species distribution and composition. Ground squirrels dig large burrow systems for refuge from predators and temperature extremes. Burrowing and foraging around burrows by squirrels may affect habitat and resource distributions for other organisms. We examined the impact of Cape ground squirrels (Xerus inauris) on vegetation, small mammals and beetles during winter and summer in grasslands on the edge of the Namib Desert. At each burrow system and paired control site without burrows, we estimated plant cover and height using quadrats (N = 8 paired sites), small mammal abundance and species richness using mark‐recapture techniques (N = 8 paired sites) and beetle abundance and species richness using pitfall traps (N = 6 paired sites, winter only). Squirrel burrowing and foraging activities resulted in lower plant cover and height, higher small mammal abundance and lower beetle abundance and species richness. Squirrels also reduced more plant cover in winter compared to summer, but had no effect on small mammal species richness. Furthermore, plant cover and height were higher in summer, whereas small mammal abundance and species richness were higher in winter. Our results suggest that Cape ground squirrels are important ecosystem engineers that influence plant and animal communities in the Namib Desert grasslands.     

Resource partitioning confirmed by isotopic signatures allows small mammals to share seasonally flooded meadows

Meadows in river deltas are characterized by a high diversity and abundance of small mammals. However, neither their spatial arrangement nor differences in their use of microhabitat can necessarily explain the dense co‐occurrence of sympatric species. We investigated how several small mammal species share a seasonally flooded meadow of limited size, testing predictions (P1) that herbivore, granivore, insectivore, and omnivore species are separated in time (dominant in different years), (P2) that sympatric species undergo isotopic partitioning, and (P3) that there are intraspecific differences in diet. Stable carbon and nitrogen isotope signatures in the hair of seven synantropic shrew, vole, and mice species were used as a proxy for their diet. We found that the three most abundant species in eight of the nine years were from different diet groups. However, based on the number of species in the functional groups, the state of small mammal community was considered unfavored in five out of the nine investigation years. In years with the greatest dominance of Apodemus agrarius, the small mammal community was characterized by decreased diversity and Micromys minutus was either in low abundance or absent. In 2014 and 2016, years of low abundance or absence of M. oeconomus, M. agrestis, and M. glareolus were both recorded in high numbers. Differences in the isotopic signatures of the three most abundant small mammal species in the community were clearly expressed and core areas in the isotopic space were separated, showing their dependence on different dietary resources. Intraspecific dietary separation between young and adult animals was observed only in M. oeconomus. Thus, the high species diversity of small mammals and the formation of their community in this investigated flooded meadow are maintained by isotopic partitioning (segregation in dietary space) and by changes in their number over time (shifting dominance).     

Similarity in occupancy of different-sized forest patches by small mammals on clearcuts: conservation implications for red-backed voles and small mustelids

Many mammalian species decline on forest sites that are harvested by clearcutting because of a loss of food, cover, and other components of stand structure. Small mustelids are impacted negatively as is the southern red-backed vole (Myodes gapperi), a principal prey species, that disappears from clearcuts within a year of harvest. These effects may be potentially ameliorated by aggregated retention harvests that leave unlogged patches on clearcuts. We tested three hypotheses (H) that (H₁) abundance, reproduction, and survival of M. gapperi populations, (H₂) total abundance, species richness, and diversity of the forest-floor small mammal community, and (H₃) the presence of small mustelids would be greater in large than small patches of retention forest on new clearcuts. We measured demographic responses of M. gapperi, total small mammals, and the presence of small mustelids (American marten, Martes americana, and small weasels (Mustela spp.)) from 2014 to 2016 in replicated treatments of four sizes (ha) of retention patches (means of 0.53, 1.50, 4.13, and 18.73) near Elkhart in south-central British Columbia, Canada. Mean abundance, reproduction, and survival attributes of M. gapperi were similar among treatment sites over the 3-year study. Overall mean abundance ranged from 3.5 to 5.3 voles per line in patches while this microtine was extirpated on clearcut sites (i.e., no forest patches). The similarity in population dynamics among the various forest patches across a gradient of increasing patch size of 4.5 to 35.3 times did not support H₁. Mean abundance, species richness, and diversity of total forest-floor small mammals were similar among treatment sites, and hence did not support H₂. Although not formally significant, mean species diversity did show a consistent increase from the largest (0.82) to the smallest (1.11) patch size, owing primarily to the presence of several generalist species such as Neotamias amoenus, Microtus, and Sorex in nearby early successional habitat. Small mustelids were present at similar levels among patch sizes, presumably in response to abundance of small mammal prey, and hence did not support H₃. Although our results were relatively short-term, the detailed assessment of population dynamics of M. gapperi indicated that habitat quality was sufficient to maintain this species regardless of patch sizes, ranging from 0.3 to 20.0 ha. Similarly, the total forest-floor small mammal community and presence of small mustelids also followed this pattern. All sizes of forest patches have conservation value and will help to maintain abundance and diversity of forest mammals, both predator and prey species, on clearcuts. Longer-term studies (e.g., at 5- to 10-year intervals) are essential to determine if our results are sustainable in augmenting forest restoration.

     

Protecting a single endangered species and meeting multiple conservation goals: an approach with Guaiacum sanctum in Yucatan Peninsula,Mexico

Aim New protected areas should consider safeguarding high conservation value sites based on multiple criteria and not just the presence of a single endangered or charismatic species. However, the extent to which complementary criteria coincide is usually unknown. We use the case of Guaiacum sanctum (Zygopyllaceae), an endangered timber tree species, to explore whether the protection of forests where this species is most abundant would meet other complementary conservation goals, such as capturing regional plant biodiversity, protecting other threatened/endemic species or safeguarding ecosystem services. Location Yucatan Peninsula, southern Mexico. Methods We conducted an analysis of the structure, composition and diversity of tree communities (including stems ≥5 cm dbh) at eight G. sanctum forest sites. We identified endemic and threatened tree species and quantified above‐ground tree biomass and carbon storage in these G. sanctum forests. Results Guaiacum sanctum forests contain 35–59 tree species on plots as small as 1000 m². The species composition of tree communities changed rapidly (high β‐diversity) across soil boundaries and rainfall regimes. Twenty‐one endemic and eight threatened tree species were recorded in our inventories. Individuals of G. sanctum represented up to 55% of the above‐ground carbon for trees ≥5 cm dbh. The high basal area of G. sanctum forests plus the high wood density, abundance, large size and longevity (more than 500 years) of G. sanctum and other tree species enhance the potential importance of these forests for carbon storage. Main conclusions A conservation strategy focused on protecting important populations of G. sanctum in the Yucatan Peninsula would have significant co‐benefits for conservation of regional tree species biodiversity and provision of critical ecosystem services. Our study illustrates a multiple criteria approach useful for the selection of areas with high conservation value on the basis of endemic, threatened species, species richness and ecosystem services.     

Habitat predictors of genetic diversity for two sympatric wetland‐breeding amphibian species

Population genetic diversity is widely accepted as important to the conservation and management of wildlife. However, habitat features may differentially affect evolutionary processes that facilitate population genetic diversity among sympatric species. We measured genetic diversity for two pond‐breeding amphibian species (Dwarf salamanders, Eurycea quadridigitata; and Southern Leopard frogs, Lithobates sphenocephalus) to understand how habitat characteristics and spatial scale affect genetic diversity across a landscape. Samples were collected from wetlands on a longleaf pine reserve in Georgia. We genotyped microsatellite loci for both species to assess population structures and determine which habitat features were most closely associated with observed heterozygosity and rarefied allelic richness. Both species exhibited significant population genetic structure; however, structure in Southern Leopard frogs was driven primarily by one outlier site. Dwarf salamander allelic richness was greater at sites with less surrounding road area within 0.5 km and more wetland area within 1.0 and 2.5 km, and heterozygosity was greater at sites with more wetland area within 0.5 km. In contrast, neither measure of Southern Leopard frog genetic diversity was associated with any habitat features at any scale we evaluated. Genetic diversity in the Dwarf salamander was strongly associated with land cover variables up to 2.5 km away from breeding wetlands, and/or results suggest that minimizing roads in wetland buffers may be beneficial to the maintenance of population genetic diversity. This study suggests that patterns of genetic differentiation and genetic diversity have associations with different habitat features across different spatial scales for two syntopic pond‐breeding amphibian species.     

Large‐scale patterns of seed removal by small mammals differ between areas of low‐ versus high‐wolf occupancy

Because most tree species recruit from seeds, seed predation by small‐mammal granivores may be important for determining plant distribution and regeneration in forests. Despite the importance of seed predation, large‐scale patterns of small‐mammal granivory are often highly variable and thus difficult to predict. We hypothesize distributions of apex predators can create large‐scale variation in the distribution and abundance of mesopredators that consume small mammals, creating predictable areas of high and low granivory. For example, because gray wolf (Canis lupus) territories are characterized by relatively less use by coyotes (C. latrans) and greater use by foxes (Vulpes vulpes, Urocyon cinereoargentus) that consume a greater proportion of small mammals, wolf territories may be areas of reduced small‐mammal granivory. Using large‐scale, multiyear field trials at 22 sites with high‐ and low‐wolf occupancy in northern Wisconsin, we evaluated whether removal of seeds of four tree species was lower in wolf territories. Consistent with the hypothesized consequences of wolf occupancy, seed removal of three species was more than 25% lower in high‐wolf‐occupancy areas across 2 years and small‐mammal abundance was more than 40% lower in high‐wolf areas during one of two study years. These significant results, in conjunction with evidence of seed consumption in situ and the absence of significant habitat differences between high‐ and low‐wolf areas, suggest that top‐down effects of wolves on small‐mammal granivory and seed survival may occur. Understanding how interactions among carnivores create spatial patterns in interactions among lower trophic levels may allow for more accurate predictions of large‐scale patterns in seed survival and forest composition.     

Quantifying disturbance resistance in an ecologically dominant species: a robust design analysis

Disturbance is now recognized as a key ecosystem process but few studies have examined its indirect effects on individuals in a population or its relationship to ecological dominance in a community. Using an ecologically dominant small mammal population in experimentally burned habitat as a model, I empirically tested the effect of disturbance on survival, abundance and fecundity and investigated whether recently burned habitat is a population sink. I also examined the effect of fire on community diversity, particularly how fire influenced dominance by bushveld gerbils Tatera leucogaster (Peters 1852). Live trapping in the first year post-fire yielded a total of 4,774 captures of 1,076 individual bushveld gerbils in a tropical savanna in southern Africa. The robust design allowed for an investigation of the effects of fire, sex and temporal variation on survival while controlling for potential differences in detection and temporary emigration. Although there were fewer individuals in burned savanna during the first 6 months post-fire, their apparent monthly survival was not significantly lowered compared with the control, with males and females surviving equally well. Fecundity, represented by proportion of females lactating, was unaffected by fire and, overall, recently burned habitat does not appear to be sink habitat. The disturbance resistance exhibited by this species is likely a contributing factor to its ecological dominance in the area, which is subject to relatively frequent fires. Results of this study highlight the need to consider disturbance regimes when evaluating patterns of species richness and evenness in an ecosystem.     

Influence of woodland remnant edges on small skinks (Richmond,New South Wales)

Abstract Habitat fragmentation due to clearing often results in an increase in edge areas compared with overall remnant size, but there are limited data on the influence of increased edge areas on generalist species. Therefore, the abundance of small (<55 mm) generalist scinid lizards in small woodland remnants of the Cumberland Plain (western Sydney, Australia) was compared. Using pitfall trapping and points of transect survey techniques, three species were encountered: Lampropholis guichenoti, Lampropholis delicata and Cryptoblepharus virgatus. The abundance and diversity of these skinks differed significantly between edge and core areas; fewer individuals were encountered on the edge of the remnants than in core sites. Cryptoblepharus virgatus was only observed in edge sites where L. guichenoti made up the greatest skink abundance. In contrast, L. delicata abundance was greatest at core sites. There was also a significant difference between the edge and core with respect to the size structure of the L. guichenoti population. Larger numbers of subadults were observed in the edge sites, whereas there were significantly fewer adults and juveniles in these areas. Habitat characteristics did not account for the skink distribution observed.     

Factors Affecting the Small Mammal Community Inside and Outside Katavi National Park, Tanzania1

Small mammal trapping showed that a minimum of 12 species live in and around Katavi National Park in western Tanzania. Species richness and abundance were greater outside the park than inside, extending results of an earlier study. Species richness and abundance were not significantly associated with vegetation cover or plant biomass but were negatively correlated with seed diversity, seed biomass, and possibly small carnivore abundance. Unfortunately, small mammal diets are unknown in this ecosystem and it can be argued that carnivores are unlikely to reduce species diversity, casting doubt on the importance of these variables. While the factors causing small mammals to fare poorly in this protected area are not yet understood, reduced food availability remains the best candidate.     

Habitat preferences and biomasses of small mammals in Swaziland

This paper describes the distribution and abundance of small mammals in Swaziland in relation to quantified habitat features. Eighteen habitat sites were sampled at seven different locations in all four geographical regions of Swaziland. Small mammal diversity (as described by the Shannon diversity index) was positively correlated with vegetation density. A total of twelve species of rodents and seven species of shrews were captured; however, only six species were caught at more than three sites. Small mammal biomasses and densities were highest at the highveld and middleveld sites. Tall grassland at all elevations supported a high diversity of small mammals. Highveld montane forest supported a high biomass and diversity of species, while no species were captured in moist forest in the Lubombo mountains.     

The abundance and diversity of Odonata along an altitudinal gradient in East Java,Indonesia

Odonate diversity in East Java was surveyed, and samplings were made during 2 years in ten sites along an altitudinal gradient. The characteristics of odonate assemblages in East Java were analyzed regarding of the number of individuals, the number of species, and Shannon's diversity index. The differences in abundance, species richness, and diversity between study sites were analyzed by an independent t‐test. There were 3270 individuals of Odonata belong to 30 species, 7 families and 2 suborders identified from all study sites. The abundance, species richness and diversity of Odonata varied between study sites. The greatest abundance of Odonata was found in Malang Coban Talun (MCT) (148.8 ± 9.5), while the lowest was in South Beach Forest (SBF) (14.4 ± 3.6). The highest species richness and diversity was found in Malang Paddy Field (MPF) (richness =14.4 ± 0.8 and H′ = 2.4 ± 0.1), while the lowest was found in South Coastal Area (SCA) (richness =2.8 ± 0.1 and H′ = 0.4 ± 0.1). A significant positive correlation was detected between the elevation and overall odonate abundance (P < 0.05), while there was not significant correlation between that and odonate species richness and diversity.     

The effect of habitat fragmentation on finescale population structure of wood frogs (Rana sylvatica)

We examined the impact of recent anthropogenic habitat fragmentation on the genetic structure of wood frog (Rana sylvatica) breeding sites in Wellington County of Ontario, Canada. In addition to geographic distance (average pairwise distance ~22 km, greatest distance ~50.22 km), four landscape features hypothesized to contribute to genetic differentiation between breeding sites were considered: road density, a major highway (highway 401), canopy cover, and watershed discontinuity. Analysis of data from 396 samples across nine breeding sites using eight microsatellite DNA loci, revealed a small degree of significant genetic structure between breeding sites. The presence of highway 401 and road density were correlated with small but statistically significant structure observed between several groups of sites. One outlier breeding site outside of Wellington County located within the city of Toronto, had significantly lower allelic richness and much larger population differentiation with the Wellington sites. Our data suggest that recent fragmentation has had an effect on wood frog population structure and also demonstrate the importance of dispersal for this species in maintaining levels of genetic diversity.     

湖南壶瓶山国家级自然保护区哺乳动物多样性的时空格局

正对生物多样性的定量分析,是生态学、生物地理学和保护生物学的中心议题之一(Purvis and Hector,2000; Brooks et al.,2006; Pavoine and Bonsall,2011)。自然保护地(protected area)不仅是地球生物多样性的"诺亚方舟",更应该是探索人与自然和谐共存方式、维持地球可持续发展的示范地(Higgins et al.,2004)。     

Butterfly community ecology: the influences of habitat type,weather patterns,and dominant species in a temperate ecosystem

We compared variation in butterfly communities across 3 years at six different habitats in a temperate ecosystem near Boulder, Colorado, USA. These habitats were classified by the local Open Space consortium as Grasslands, Tallgrass, Foothills Grasslands, Foothills Riparian, Plains Riparian, and Montane Woodland. Rainfall and temperature varied considerably during these years. We surveyed butterflies using the Pollard‐Yates method of invertebrate sampling and compared abundance, species richness, and diversity across habitats and years. Communities were most influenced by habitat, with all three quantitative measures varying significantly across habitats but only two measures showing variation across years. Among habitats, butterfly abundance was higher in Plains Riparian sites than in Montane Woodland or Grassland sites, though diversity was lowest in Plains Riparian areas. Butterfly species richness was higher in Foothills Riparian sites than it was in all but one other habitat (Tallgrass). Among years, butterfly abundance and species richness were lower during the year of least rainfall and highest temperatures, suggesting a substantial impact of the hot, dry conditions. Across habitats and years, butterfly abundance was consistently high at Plains Riparian and Foothills Riparian sites, and richness and diversity were consistently high in Foothills Riparian areas. These two habitats may be highly suitable for butterflies in this ecosystem, regardless of weather conditions. Generally low abundance and species richness in Montane Woodlands sites, particularly in 2002, suggested low suitability of the habitat to butterflies in this ecosystem, and this may be especially important during drought‐like conditions. Finally, to examine the effect that the presence of the very abundant non‐native species Pieris rapae L. (Lepidoptera: Pieridae) has on these communities, we re‐analyzed the data in the absence of this species. Excluding P. rapae dramatically reduced variation of both butterfly abundance and diversity across habitats, highlighting the importance of considering community membership in analyses like ours.     

Community assembly of Diptera following restoration of mined boreal bogs: taxonomic and functional diversity

Peat mining causes major degradation to bogs and natural regeneration of these sites is slow and often incomplete. Thus, restoration is an important tool for re-establishing natural ecosystem properties (although perhaps not the original species pool) in mined bogs. Because faunal recovery cannot be taken for granted following plant restoration, we assessed community assembly of higher flies (Diptera: Brachycera) in previously mined bogs 7 years after restoration. Species assemblages in restored sites were compared to those in nearby natural and abandoned mined sites. The three treatment types did not differ significantly in overall species composition, suggesting high resilience to disturbance. However, species richness and evenness were generally lower in abandoned sites than restored and natural sites, which had similar abundance distributions, indicating that restoration enhanced recovery of species diversity and community structure. Functional traits (trophic group, body size) provided a different insight into the status of restored sites. Trophic and small size-class (<5 mm) composition in restored sites were similar to those in abandoned sites. However, high species richness estimates indicated that predators and saprophages successfully colonized restored sites. Species assemblages were mostly affected by coverage of bare peat, Sphagnum mosses and ericaceous shrubs; trophic assemblages were affected by variables directly linked to feeding habits. Our results suggest that active restoration is needed for the renewal of high species and trophic diversity, although it is clear from environmental conditions and functional traits that the restored sites are not yet fully functioning peatlands 7 years after restoration.     

More long‐unburnt forest will benefit mammals in Australian sub‐alpine forests and woodlands

The composition of mammalian communities in Australia's Eucalyptus forests and woodlands is known to be affected by fire. However, there are few published studies that compare mammal assemblages in recently burnt and long‐unburnt forests because there are few areas with long‐term fire history data. Understanding the value of long‐unburnt forest is important because it is becoming rare in fire‐prone regions of the world, such as south‐eastern Australia, partly because of the widespread use of prescribed burning. We deployed wildlife cameras for 28 trap‐nights at each of 81 sites that ranged from 0.5 to at least 96 years since the last fire. We recorded a total of 15 native mammal species. At least one mammal species was recorded at 80 of the 81 sites. Significantly more species were detected at long‐unburnt sites (>96 years since fire) than sites 0.5–12 years since the last fire. Species composition varied significantly between sites 0.5–12 years and >96 years since the last fire but did not vary between sites 0.5–2 years and 6–12 years since the last fire. Although there was not one category of time since fire (i.e. 0.5–2 years, 6–12 years and >96 years) in which all 15 native mammal species were recorded, long‐unburnt sites were significantly more important for the occurrence of seven mammal species; intermediate and recently burnt sites were significantly more important for one species. Our results suggested that, while a diversity of fire ages is important for conserving mammalian diversity, long‐unburnt forests and woodlands (which comprised only 8% of our study area) are disproportionately important for mammal conservation. Our results add to a growing body of the literature from south‐eastern Australia, suggesting that remaining long‐unburnt forest should be afforded protection from fire and more forest should be transitioned to long unburnt.     

Influence of Forest Fragmentation on the Winter Abundance of Mammals in Mt. Chirisan National Park,South Korea

Abstract: We examined the influence of both local habitat and landscape variables on mammal species abundance in a forest fragmented by road construction and in continuous forest in 8 study sites in Mt. Chirisan National Park, South Korea, from 2001 to 2004. We recorded tracks of 8 species of mammals, Siberian weasels (Mustela sibirica), yellow-throated martens (Martes flavigula), Bengal cats (Felis bengalensis), wild boars (Sus scrofa), water deer (Hydropotes inermis), roe deer (Capreolus capreolus), Korean hares (Lepus coreanus), and red squirrels (Sciurus vulgaris), on the snow on 8 2-km transects in our study areas. There were significant differences in density of snags, mean tree basal area, and in shrub coverage between the fragmented and unfragmented forest areas. We found significant differences in abundance index of tracks between the fragmented and unfragmented areas for 5 mammal species; the others had even distributions. Of the 8 mammal species analyzed, 5 species related to landscape and local vegetation variables in a stepwise approach with repeated measures. Landscape variables are significant predictors of abundance for many mammal species. Forest managers should consider multiple measures of forest fragmentation sensitivity when making forest management decisions.     

Effects of alien pine plantations on small mammal community structure in a southern African biodiversity hotspot

Commercial plantations and alien tree invasions often have substantial negative impacts on local biodiversity. The effect of plantations on faunal communities in the fire‐adapted fynbos vegetation of the Cape Floristic Region biodiversity hotspot is not yet well quantified. We studied small mammal community structure in alien Pinus radiata plantations and adjacent fynbos regenerating after clear‐felling of plantations on the Cape Peninsula, South Africa. Small mammal sampling over 1,800 trap‐nights resulted in 480 captures of 345 individuals (excluding recaptures) representing six species. Significantly more species, individuals (12 X) and biomasses (29 X) of small mammals occurred on recovering fynbos sites compared to plantations. This was commensurate with a higher diversity of plant growth forms, vegetation densities and live vegetation biomass. Only one small mammal species, the pygmy mouse (Mus minutoides), was consistently trapped within plantations. Fynbos sites were dominated by three small mammal species that are ecological generalists and early successional pioneer species, rendering the recovering fynbos slightly depauperate in terms of species richness and evenness relative to other studies done in pristine fynbos. We make three recommendations for forestry that would facilitate the restoration of more diverse natural plant communities and progressively more diverse and dynamic small mammal assemblages in a key biodiversity hotspot.