Population and community ecology as a science are about 100 years old,and we discuss here our opinion of what approaches have progressed well and which point to possible future directions.The three major threads withi...Population and community ecology as a science are about 100 years old,and we discuss here our opinion of what approaches have progressed well and which point to possible future directions.The three major threads within pop-ulation and community ecology are theoretical ecology,statistical tests and models,and experimental ecology.We suggest that our major objective is to understand what factors determine the distribution and abundance of organ-isms within populations and communities,and we evaluate these threads against this major objective.Theoretical ecology is elegant and compelling and has laid the groundwork for achieving our overall objectives with useful simple models.Statistics and statistical models have contributed informative methods to analyze quantitatively our understanding of distribution and abundance for future research.Population ecology is difficult to carry out in thefield,even though we may have all the statistical methods and models needed to achieve results.Community ecol-ogy is growing rapidly with much description but less understanding of why changes occur.Biodiversity science cuts across all these subdivisions but rarely digs into the necessary population and community science that might solve conservation problems.Climate change affects all aspects of ecology but to assume that everything in pop-ulation and community ecology is driven by climate change is oversimplified.We make recommendations on how to advance thefield with advice for present and future generations of population and community ecologists.展开更多
Long-term monitoring is critical to determine the stability and sustainability of wildlife populations,and if change has occurred,why.We have followed population density changes in the small mammal community in the bo...Long-term monitoring is critical to determine the stability and sustainability of wildlife populations,and if change has occurred,why.We have followed population density changes in the small mammal community in the boreal forest of the southern Yukon for 46 years with density estimates by live trapping on 3-5 unmanipulated grids in spring and autumn.This community consists of 10 species and was responsible for 9%of the energy flow in the herbivore component of this ecosystem from 1986 to 1996,but this increased to 38%from 2003 to 2014.Small mammals,although small in size,are large in the transfer of energy from plants to predators and decomposers.Four species form the bulk of the biomass.There was a shift in the dominant species from the 1970s to the 2000s,with Myodes rutilus increasing in relative abundance by 22%and Peromyscus maniculatus decreasing by 22%.From 2007 to 2018,Myodes comprised 63%of the catch,Peromyscus 20%,and Microtus species 17%.Possible causes of these changes involve climate change,which is increasing primary production in this boreal forest,and an associated increase in the abundance of 3 rodent predators,marten(Martes americana),ermine(Mustela ermine)and coyotes(Canis latrans).Following and understanding these and potential future changes will require long-term monitoring studies on a large scale to measure metapopulation dynamics.The small mammal community in northern Canada is being affected by climate change and cannot remain stable.Changes will be critically dependent on food-web interactions that are species-specific.展开更多
Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons.First,climate change is affecting the abiotic environment(temperature,rainfall and growing season)and dr...Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons.First,climate change is affecting the abiotic environment(temperature,rainfall and growing season)and driving changes in plant productivity and predator-prey interactions.Second,simultaneously change is occurring because of mammal species reintroductions and rewilding.The key ecological question is the impact these faunal changes will have on trophic dynamics.Primary productivity in the boreal forest is increasing because of climatic warming,but plant species composition is unlikely to change significantly during the next 50-100 years.The 9-10-year population cycle of snowshoe hares will persist but could be reduced in amplitude if winter weather increases predator hunting efficiency.Small rodents have increased in abundance because of increased vegetation growth.Arctic ground squirrels have disappeared from the forest because of increased predator hunting efficiency associated with shrub growth.Reintroductions have occurred for 2 reasons:human reintroductions of large ungulates and natural recolonization of mammals and birds extending their geographic ranges.The deliberate rewilding of wood bison(Bison bison)and elk(Cervus canadensis)has changed the trophic structure of this boreal ecosystem very little.The natural range expansion of mountain lions(Puma concolor),mule deer(Odocoileus hemionus)and American marten(Martes americana)should have few ecosystem effects.Understanding potential changes will require long-term monitoring studies and experiments on a scale we rarely deem possible.Ecosystems affected by climate change,species reintroductions and human alteration of habitats cannot remain stable and changes will be critically dependent on food web interactions.展开更多
文摘Population and community ecology as a science are about 100 years old,and we discuss here our opinion of what approaches have progressed well and which point to possible future directions.The three major threads within pop-ulation and community ecology are theoretical ecology,statistical tests and models,and experimental ecology.We suggest that our major objective is to understand what factors determine the distribution and abundance of organ-isms within populations and communities,and we evaluate these threads against this major objective.Theoretical ecology is elegant and compelling and has laid the groundwork for achieving our overall objectives with useful simple models.Statistics and statistical models have contributed informative methods to analyze quantitatively our understanding of distribution and abundance for future research.Population ecology is difficult to carry out in thefield,even though we may have all the statistical methods and models needed to achieve results.Community ecol-ogy is growing rapidly with much description but less understanding of why changes occur.Biodiversity science cuts across all these subdivisions but rarely digs into the necessary population and community science that might solve conservation problems.Climate change affects all aspects of ecology but to assume that everything in pop-ulation and community ecology is driven by climate change is oversimplified.We make recommendations on how to advance thefield with advice for present and future generations of population and community ecologists.
文摘Long-term monitoring is critical to determine the stability and sustainability of wildlife populations,and if change has occurred,why.We have followed population density changes in the small mammal community in the boreal forest of the southern Yukon for 46 years with density estimates by live trapping on 3-5 unmanipulated grids in spring and autumn.This community consists of 10 species and was responsible for 9%of the energy flow in the herbivore component of this ecosystem from 1986 to 1996,but this increased to 38%from 2003 to 2014.Small mammals,although small in size,are large in the transfer of energy from plants to predators and decomposers.Four species form the bulk of the biomass.There was a shift in the dominant species from the 1970s to the 2000s,with Myodes rutilus increasing in relative abundance by 22%and Peromyscus maniculatus decreasing by 22%.From 2007 to 2018,Myodes comprised 63%of the catch,Peromyscus 20%,and Microtus species 17%.Possible causes of these changes involve climate change,which is increasing primary production in this boreal forest,and an associated increase in the abundance of 3 rodent predators,marten(Martes americana),ermine(Mustela ermine)and coyotes(Canis latrans).Following and understanding these and potential future changes will require long-term monitoring studies on a large scale to measure metapopulation dynamics.The small mammal community in northern Canada is being affected by climate change and cannot remain stable.Changes will be critically dependent on food-web interactions that are species-specific.
基金Research funding was provided by the Natural Science and Engineering Research Council of Canada(RB,CK,SB)and Environment Yukon(TJ,ST).
文摘Community and ecosystem changes are happening in the pristine boreal forest ecosystem of the Yukon for 2 reasons.First,climate change is affecting the abiotic environment(temperature,rainfall and growing season)and driving changes in plant productivity and predator-prey interactions.Second,simultaneously change is occurring because of mammal species reintroductions and rewilding.The key ecological question is the impact these faunal changes will have on trophic dynamics.Primary productivity in the boreal forest is increasing because of climatic warming,but plant species composition is unlikely to change significantly during the next 50-100 years.The 9-10-year population cycle of snowshoe hares will persist but could be reduced in amplitude if winter weather increases predator hunting efficiency.Small rodents have increased in abundance because of increased vegetation growth.Arctic ground squirrels have disappeared from the forest because of increased predator hunting efficiency associated with shrub growth.Reintroductions have occurred for 2 reasons:human reintroductions of large ungulates and natural recolonization of mammals and birds extending their geographic ranges.The deliberate rewilding of wood bison(Bison bison)and elk(Cervus canadensis)has changed the trophic structure of this boreal ecosystem very little.The natural range expansion of mountain lions(Puma concolor),mule deer(Odocoileus hemionus)and American marten(Martes americana)should have few ecosystem effects.Understanding potential changes will require long-term monitoring studies and experiments on a scale we rarely deem possible.Ecosystems affected by climate change,species reintroductions and human alteration of habitats cannot remain stable and changes will be critically dependent on food web interactions.
