scholarly journals Influence of variable retention harvests on forest ecosystems. II. Diversity and population dynamics of small mammals

2001 ◽  
Vol 38 (6) ◽  
pp. 1234-1252 ◽  
Author(s):  
Thomas P. Sullivan ◽  
Druscilla S. Sullivan
Keyword(s):  
Population Dynamics ◽  
Small Mammals ◽  
Forest Ecosystems ◽  
Variable Retention

Effects of Tree Island Size and Water on the Population Dynamics of Small Mammals in the Everglades

2002 ◽  
pp. 429-444 ◽  
Author(s):  
Michael S. Gaines ◽  
Christopher R. Sasso ◽  
James E. Diffendorfer ◽  
Harald Beck
Keyword(s):  
Population Dynamics ◽  
Small Mammals ◽  
Island Size ◽  
Tree Island

scholarly journals Lightning Damage Facilitates Beetle Colonization of Tropical Trees

2020 ◽  
Author(s):  
Brady P Parlato ◽  
Evan M Gora ◽  
Stephen P Yanoviak
Keyword(s):  
Population Dynamics ◽  
Tropical Forest ◽  
Forest Ecosystems ◽  
Tropical Trees ◽  
Pine Forests ◽  
Forest Trees ◽  
Beetle Population ◽  
Tree Diameter ◽  
Crown Dieback ◽  
The Relationship

Abstract Lightning is a common agent of disturbance in many forest ecosystems. Lightning-damaged trees are a potentially important resource for beetles, but most evidence for this association is limited to temperate pine forests. Here, we evaluated the relationship between lightning damage and beetle colonization of tropical trees. We recorded the number of beetle holes on the trunks of trees from 10 strike sites (n = 173 lightning-damaged trees) and 10 matching control sites (n = 137 control trees) in Panama. The trunks of lightning-struck trees had 370% more beetle holes than control trees. The abundance of beetle holes increased with increasing total crown dieback among both control and lightning-damaged trees, and with larger tree diameter among lightning-struck trees. Beetle holes also were more abundant in trunk sections of lightning-damaged trees located directly below a damaged section of the crown. The results of this study suggest that lightning damage facilitates beetle colonization in tropical forest trees and provide a basis for investigations of the effects of lightning-caused disturbance on beetle population dynamics and assemblage structure.

Comparative population dynamics of large and small mammals in the Northern Hemisphere: deterministic and stochastic forces

Ecography ◽  
2011 ◽  
Vol 36 (4) ◽  
pp. 439-446 ◽  
Author(s):  
Guiming M. Wang ◽  
N. Thompson Hobbs ◽  
Norman A. Slade ◽  
Joseph F. Merritt ◽  
Lowell L. Getz ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Northern Hemisphere ◽  
Small Mammals ◽  
Stochastic Forces ◽  
Comparative Population

Novel introductions and epidemic dynamics of the sudden oak death pathogen Phytophthora ramorum in Oregon forests

2020 ◽  
Author(s):  
Nicholas C Carleson ◽  
Hazel Daniels ◽  
Paul Reeser ◽  
Alan Kanaskie ◽  
Sarah Navarro ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Population Dynamics ◽  
Microsatellite Loci ◽  
Forest Ecosystems ◽  
Principal Component ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Clonal Lineage ◽  
Epidemic Dynamics ◽  
One Year

Sudden oak death caused by Phytophthora ramorum has been actively managed in Oregon since the early 2000’s. To date, this epidemic has been driven mostly by the NA1 clonal lineage of P. ramorum, but an outbreak of the EU1 lineage has recently emerged. Here we contrast the population dynamics of the NA1 outbreak first reported in 2001 to the outbreak of the EU1 lineage first detected in 2015. We tested if any of the lineages were introduced more than once. Infested regions of the forest were sampled between 2013-2018 (n = 903) and strains were genotyped at 15 microsatellite loci. Most genotypes observed were transient, with 272 of 358 unique genotypes emerging one year and disappearing the next. Diversity of EU1 was very low and isolates were spatially clustered (< 8 km apart), suggesting a single EU1 introduction. Some forest isolates are genetically similar to isolates collected from a local nursery in 2012, suggesting introduction of EU1 from this nursery or simultaneous introduction to both the nursery and latently into the forest. In contrast, the older NA1 populations were more polymorphic and spread over 30 km2. Principal component analysis supported two to four independent NA1 introductions. The NA1 and EU1 epidemics infest the same area but show disparate demographics owing to initial introductions of the lineages spaced 10 years apart. Comparing these epidemics provides novel insights into patterns of emergence of clonal pathogens in forest ecosystems.

scholarly journals Testing predator - prey theory by studying fluctuating populations of small mammals.

1995 ◽  
Vol 22 (1) ◽  
pp. 89 ◽  
Author(s):  
S. Boutin
Keyword(s):  
Population Dynamics ◽  
Small Mammals ◽  
Limit Cycles ◽  
Functional Responses ◽  
Predator Satiation ◽  
Linear Type ◽  
Small Component ◽  
Wide Range ◽  
Fluctuating Populations

Fluctuating populations of small mammals provide an excellent opportunity to study the functional and numerical responses of predators because of the wide range in prey density that occurs. I reinterpret data from six studies that have examined the role of predation in the population dynamics of voles in California, southern Sweden and western Finland, of snowshoe hares in northern Canada, and of house mice and rabbits in Australia. Most studies have measured functional responses by relying on changes in diet as reflected by scat or stomach contents. These methods are probably biased toward showing predator satiation. Contrary to previous conclusions I find that there is little evidence for non-linear (Type 111) functional-response curves or predator satiation at high prey densities. Recent studies indicate that the functional and numerical responses of predators can be rapid and strong enough to initiate cyclic declines, dampen fluctuations, or even cause stable numbers. The exception to this appears to be the irruptions of mice and rabbits in Australia. I propose a general explanation for the role of predation whereby the effect of predation is largely dependent on the entire prey community. When potentially cyclic prey are a small component of the overall prey biomass, generalist predators are able to prevent fluctuations by strong functional or numerical responses. As the prey community becomes dominated by a few species that fluctuate, limit cycles predominate. Limit cycles turn into irruptive population dynamics when seasonal prey reproduction is eliminated because of extended periods of vegetation growth (vegetation flushes following drought). In the future we must test assumptions underlying the way we study predation by telemetric monitoring of prey mortality and by experimentally manipulating predation.

scholarly journals Giardia and Other Parasites of Small Mammals in Grand Teton National Park

1989 ◽  
Vol 13 ◽  
pp. 125-127
Author(s):  
William O'Dell ◽  
Raychel Watkins ◽  
Aelita Pinter
Keyword(s):  
Population Dynamics ◽  
Small Mammals ◽  
Small Mammal ◽  
National Park ◽  
Grand Teton National Park ◽  
Microtus Spp

The objectives of this study are to document the effects of parasitism on vole (Microtus spp.) population dynamics and to determine the potential of small mammals in Grand Teton National Park to serve as reservoirs of human parasites. Immediate goals for 1989 were to (1) continue the documentation of the incidence and prevalence of small mammal parasites, (2) determine the age at which Giardia infections are contracted by the Microtus host, (3) identify ticks associated with small mammals, and (4) survey small mammals for Babesia infections.

scholarly journals Effects of Different Soils on the Biomass and Photosynthesis of Rumex nepalensis in Subalpine Region of Southwestern China

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 73
Author(s):  
Heliang He ◽  
Lan Yu ◽  
Xiaocheng Yang ◽  
Lin Luo ◽  
Jia Liu ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Forest Ecosystems ◽  
Soil Microbes ◽  
Extracellular Enzymes ◽  
Nitrogen Concentration ◽  
Southwestern China ◽  
Shoot Biomass ◽  
Soluble Nitrogen ◽  
Total Biomass ◽  
Picea Asperata

The performance of Rumex nepalensis, an important medicinal herb, varies significantly among subalpine grasslands, shrublands and forest ecosystems in southwestern China. Plant–soil feedback is receiving increasing interest as an important driver influencing plant growth and population dynamics. However, the feedback effects of soils from different ecosystems on R. nepalensis remain poorly understood. A greenhouse experiment was carried out to identify the effects of different soil sources on the photosynthesis and biomass of R. nepalensis. R. nepalensis was grown in soils collected from the rooting zones of R. nepalensis (a grassland soil, RS treatment), Hippophae rhamnoides (a shrub soil, HS treatment), and Picea asperata (a forest soil, PS treatment). The chlorophyll contents, net photosynthetic rates, and biomasses of R. nepalensis differed significantly among the three soils and followed the order of RS > HS > PS. After soil sterilization, these plant parameters followed the order of RS > PS > HS. The total biomass was 16.5 times higher in sterilized PS than in unsterilized PS, indicating that the existence of soil microbes in P. asperata forest ecosystems could strongly inhibit R. nepalensis growth. The root to shoot biomass ratio of R. nepalensis was the highest in the sterilized PS but the lowest in the unsterilized PS, which showed that soil microbes in PS could change the biomass allocation. Constrained redundancy analysis and path analysis suggested that soil microbes could impact the growth of R. nepalensis via the activities of soil extracellular enzymes (e.g., β-1,4-N-acetylglucosaminidase (NAG)) in live soils. The soil total soluble nitrogen concentration might be the main soil factor regulating R. nepalensis performance in sterilized soils. Our findings underline the importance of the soil microbes and nitrogen to R. nepalensis performance in natural ecosystems and will help to better predict plant population dynamics.

Small Mammals: Their Productivity and Population Dynamics

1976 ◽  
Vol 13 (3) ◽  
pp. 991
Author(s):  
J. R. Flowerdew ◽  
F. B. Golley ◽  
K. Petrusewicz ◽  
L. Ryszkowski
Keyword(s):  
Population Dynamics ◽  
Small Mammals
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