scholarly journals Predicting the Effects of Hemlock Woolly Adelgid on Microhabitat Structure and Small Mammal Communities

2018 ◽  
Author(s):  
Allyson L. Degrassi

AbstractHemlock woolly adelgid (HWA) invasion and preemptive logging practices alter the habitat structure of New England forests and may indirectly affect associated small mammal communities. Microhabitat structure was measured and small mammals were censused in eight large experimental plots to quantify and predict these effects. The Harvard Forest Long-Term Ecological Research experiment is a replicated two-block design that includes four 0.81-ha canopy treatments: 1) Hemlock Control, 2) Hardwood Control, 3) Girdled Treatment, in which hemlock trees were killed by girdling in 2005 and left standing to simulate HWA invasion, and 4) Logged Treatment, in which trees were removed to simulate preemptive logging management practices. Nine microhabitat characteristics were measured from plot photos revealing differences among microhabitat structure. Small mammals were censused with arrays of 49 Sherman traps per plot and population sizes of common species were estimated with mark-recapture analysis. Between 6 and 8 mammal species were recorded in all treatments and species composition varied slightly. Populations of two common rodents (Peromyscus spp.) were not affected by treatment, but the southern red-backed vole population was greatest in the Girdled treatment. Estimated species richness was greater in the Girdled treatment than the Hemlock control, but richness did not differ between Girdled and Logged treatments, which suggests preemptive logging is as detrimental to some small mammal species as HWA invasion. Overall, nine years post disturbance, there is little evidence of a major shift in small mammal community structure in response to woolly adelgid invasion, with only minor changes in relative abundance.


Author(s):  
R. Moore ◽  
M. Wood

As part of the National Park Service's goal of maintaining an area in as natural condition as possible, Yellowstone National Park in 1972 developed a fire policy whereby natural fires were allowed to burn in wilderness areas of the park. Several investigators have studied the relationship between small mammals and fire due to timber management practices (Gashwiler, 1970 and Tevis, 1956) but few studies have investigated the changes in abundance and composition of species of small mammals after recent natural fires (Bendell 1974). The purpose of this ongoing study is to quantify the effects that recent natural fires have had upon small mammal communities. Two burn sites were studies, the Divide fire which burned in 1976 on the south arm of Yellowstone Lake, and the Trail Creek Fire which burned in 1974 on the southeast arm of the lake.



Animals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 334 ◽  
Author(s):  
Linas Balčiauskas ◽  
Laima Balčiauskienė ◽  
Vitalijus Stirkė

Small mammals are not only pests but also an important part of agricultural ecosystems. The common vole is a reference species for risk assessment of plant protection products in the European Union, but no data about the suitability of the species in the Baltic countries are present so far. Using the snap-trap line method, we evaluated species composition, abundance, and diversity of small mammal communities in commercial orchards and berry plantations in Lithuania, testing the predictions that (i) compared with other habitats, small mammal diversity in fruit farms is low, and (ii) the common vole is the dominant species. The diversity of small mammals was compared with control habitats and the results of investigations in other habitats. Out of ten small mammal species registered, the most dominant were common vole and striped field mouse. Small mammal diversity and abundance increased in autumn and decreased in line with the intensity of agricultural practices but were not dependent on crop type. In the most intensively cultivated fruit farms, small mammals were not found. The diversity of small mammal communities in fruit farms was significantly higher than in crop fields and exceeded the diversities found in most types of forests except those in rapid succession.



2007 ◽  
Vol 16 (6) ◽  
pp. 728 ◽  
Author(s):  
Karl W. Larsen ◽  
Ian T. Adams ◽  
Diane L. Haughland

We studied the small mammal community across a mosaic of habitats created by a large wildfire in the mixed-wood boreal forest of Alberta, Canada, 5 years after the fire occurred. We focussed on four habitat types within this landscape mosaic, namely burnt stands, stands of unburnt forest within the burn, unburnt forest on the periphery of the fire, and areas harvested before the fire (and subsequently burnt). The abundance of the two most common species – red-backed voles (Clethrionomys gapperi) and deer mice (Peromyscus maniculatus) – often differed inside v. outside the burn’s perimeter; however, reproduction, survival and abundance showed little to no correlation with habitat. Year-to-year changes in the relative abundance of these two species appeared greater within the burn’s periphery; the heterogeneity of the burnt landscape also supported a higher diversity of small mammal species than seen at the periphery. Comparison of our results with those collected by a coincidental study of forest harvesting suggests that the responses of the communities and populations of the animals to the two disturbance types were relatively similar. The value of long-term and chronosequence studies notwithstanding, detailed study of the wildlife communities shaped by individual wildfires improves our overall understanding of the ecological effects of natural and anthropogenic disturbances.



Biologia ◽  
2012 ◽  
Vol 67 (6) ◽  
Author(s):  
Linas Balčiauskas ◽  
Laima Balčiauskienė ◽  
Agnė Janonytė

AbstractThe influence of the annual spring floods on small mammal communities was studied in the Nemunas River Delta, SW Lithuania. The aim of the investigation was to compare the diversity of small mammals inhabiting spring-flooded meadows, meadows not subjected to flooding and spring-flooded forest in years characterized by differing heights and durations of spring flood. In the years of the high flood, the number of species and diversity index were higher, while index of dominance was less than in the years of low flood. Significantly, the highest proportions of Apodemus agrarius were recorded in spring-flooded meadows in years of high flood (41.7%), while Microtus oeconomus occurred in the highest proportions in spring-flooded meadows in years of low flood (66.8%) and in meadows not subjected to flooding (47.1%). In non-flooded areas, M. Oeconomus is not expelled by the floods and outcompetes other species. After high levels of flooding, during the process of re-population, the voles may be outcompeted by A. agrarius. In the absence of dominant species, greater opportunities existed for the establishment of more species (13 species in flooded meadows). Micromys minutus accounted for up to 19.5–30.1% in the years of high flood. We concluded that the annual spring floods in the Nemunas Delta had no long-term negative effects, the number of small mammal species and their abundance had been restored in just a few months. The worst consequences of the high flood were recorded in forest habitat. Spring floods, and especially the higher floods, are natural environmental agents, maintaining the high diversity of small mammals in meadows and reed-beds.



2014 ◽  
Vol 36 (1) ◽  
pp. 35 ◽  
Author(s):  
T. L. Moore ◽  
L. E. Valentine ◽  
M. D. Craig ◽  
G. E. St J. Hardy ◽  
P. A. Fleming

Loss of mammal species in Australia in the last 200 years has been attributed to many factors including habitat removal and altered fire regimes. Decline in tree condition could contribute further to the ongoing decline of mammals. Eucalyptus wandoo trees are currently undergoing a decline in condition that can result in a loss of canopy and other changes to the habitat. This paper examines the relationships between E. wandoo tree condition, habitat characteristics and small mammal species richness and abundance. Live-capture trapping was conducted at 24 E. wandoo sites at Dryandra State Forest and Wandoo Conservation Park, Western Australia. Condition and microhabitat variables of E. wandoo were recorded for each site. Generalised additive mixed models revealed a range of habitat and tree condition characteristics that influenced small mammal abundance and species richness, including site litter cover, crown dieback, understorey vegetation cover and tree density. The availability of coarse woody debris played a large role in explaining the abundance of Cercartetus concinnus and Antechinus flavipes, along with other microhabitat and tree condition variables, such as tree leaf litter and crown dieback. Epicormic growth, crown density and the distance to the drift fence from E. wandoo trees were the common variables in the best model for the abundance of Sminthopsis griseoventer. The decline in condition of E. wandoo and the subsequent modifications to the microhabitat are correlated with changes in the small mammal community. A better understanding of how the decline of E. wandoo impacts small mammal communities could improve management practices in E. wandoo woodlands.



1983 ◽  
Vol 61 (5) ◽  
pp. 970-980 ◽  
Author(s):  
Arthur M. Martell

Changes in small mammal communities following logging were monitored in clear-cut and strip-cut upland black spruce (Picea mariana) stands and in selectively cut mixed wood stands in north-central Ontario. Clear-cutting and subsequent scarification essentially eliminated the vegetative cover. Much of the ground cover recovered within 5 years and shrubs within 12 years, but mosses and lichens took much longer. The small mammal community in both clear-cut and strip-cut stands changed over the first three years after logging from one dominated by southern red-backed voles (Clethrionomys gapperi) to one dominated by deer mice (Peromyscus maniculatus) and then remained relatively stable for up to 13 years after harvest. That shift was not apparent in selectively cut mixed wood stands where the composition of the small mammal community was similar between uncut stands and stands 4–23 years after harvest. There was relatively little change in total numbers of small mammals after logging. In general, the diversity and evenness of small mammals increased or remained stable in the first 1–3 years following harvest, decreased on older (3–16 years) cuts, and then increased to values similar to those in uncut stands on the oldest (19–23 years) cuts.



Author(s):  
Jon Forde ◽  
Norman Sloan

Specifically, the objectives of this research project were to: 1) Census burned and unburned grassland areas for breeding populations of birds and small mammals. Population censuses have been made on areas prescribed burned between 1973 and 1978 as well as the areas burned in the spring of 1981; 2) Analyze study transect vegetation to determine the impact of burning treatments on prairie vegetation and its relationship to bird and small mammal densities; 3) Provide usable management recommendations that will aid not only in vegetation maintenance but also with the animal populations associated with the grasslands.



Author(s):  
Eric Adjei Lawer ◽  
Anne-Christine Mupepele ◽  
Alexandra-Maria Klein

AbstractLogging and mining are widespread in most West African countries and considering their socio-economic importance, little is known about their ecological impacts. In this study, we investigated the effects of chainsaw milling (logging) and artisanal mining on terrestrial small mammal communities in a tropical forest in Ghana. For this, we compared abundance, diversity measures and community composition of small mammals active at the forest floor in logged, mined and undisturbed forest sites. We found that abundance was higher in logged and undisturbed forest sites than in mined sites. Small mammal species richness, Shannon diversity and Pielou’s evenness did not differ significantly among the three forest disturbance categories. Community composition of small mammals varied between mined and undisturbed sites as well as between mined and logged sites, suggesting differential species responses to altered environments. This may be due to the presence of pits in mined forest sites, hence a reduction in exploitable ground habitat structures for shelter, nesting or food. Overall, our results suggest that artisanal mining has strong impacts on community composition of forest floor small mammals in tropical forests while the effect of logging by chainsaw milling activities is minimal, especially when practiced at low intensity. This effect was moderated by elevation and distance to streams that equally shaped small mammal communities. More research on the effects of specific forms of logging and mining activities on small mammals are urgently needed to better protect species in forests impacted by logging and mining.



Author(s):  
E.M. Luchnikova ◽  
◽  
V.B. Ilyashenko ◽  
N.S. Teplova ◽  
A.V Kovalevskiy ◽  
...  

The paper is devoted to studying the influence of agricultural lands on the formation of small mammal communities in the pine forests of the Tom River Valley. For the analysis, we took sites of natural and artificial pine forests of different areas experiencing various anthropogenic pressures. A relationship was found between the size of the pine forest and its resistance to invasive species. The creation of artificial pine forests in the forest-steppe does not lead to the formation of typical forest communities of small mammals, due to their limited ability to resettle.



2011 ◽  
Vol 76 (3) ◽  
pp. 397-400 ◽  
Author(s):  
J. Tyler Faith ◽  
James F. O'Connell

AbstractTight Entrance Cave (TEC) in southwestern Australia provides a Pleistocene sequence documenting the extinction of 14 large mammal species. This record has been interpreted as indicating that extinctions did not occur during or before the penultimate glacial maximum (PGM) and that humans played a primary role in the extinctions. However, it remains possible that the majority of extinct megafauna persisted no later than the PGM. The TEC extinctions correspond with vegetation change, a cooling/drying trend, increased biomass burning, and increasingly unstable small mammal communities. The initiation of these trends predates human arrival on the continent and implies environmentally mediated extinctions.



Sign in / Sign up

Export Citation Format

Share Document