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Life history and spatial traits predict extinction risk due to climate change
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There is an urgent need to develop effective vulnerability assessments for evaluating the conservation status of species in a changing climate1. Several new assessment approaches have been proposed for evaluating the vulnerability of species to climate change 2–5 based on the expectation that established assessments such as the IUCN Red List6 need revising or superseding in light of the threat that climate change brings. However, although previous studies have identified ecological and life history attributes that characterize declining species or those listed as threatened7–9, no study so far has undertaken a quantitative analysis of the attributes that cause species to be at high risk of extinction specifically due to climate change. We developed a simulation approach based on generic life history types to show here that extinction risk due to climate change can be predicted using a mixture of spatial and demographic variables that can be measured in the present day without the need for complex forecasting models. Most of the variables we found to be important for predicting extinction risk, including occupied area and population size, are already used in species conservation assessments, indicating that present systems may be better able to identify species vulnerable to climate change than previously thought. Therefore, although climate change brings many new conservation challenges, we find that it may not be fundamentally different from other threats in terms of assessing extinction risks.
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Life history predicts risk of species decline in a stochastic world
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Understanding what traits determine the extinction risk of species has been a long-standing challenge. Natural populations increasingly experience reductions in habitat and population size concurrent with increasing novel environmental variation owing to anthropogenic disturbance and climate change. Recent studies show that a species risk of decline towards extinction is often non-random across species with differ- ent life histories. We propose that species with life histories in which all stage-specific vital rates are more evenly important to population growth rate may be less likely to decline towards extinction under these pressures. To test our prediction, we modelled declines in population growth rates under simulated stochas- tic disturbance to the vital rates of 105 species taken from the literature. Populations with more equally important vital rates, determined using elasticity analysis, declined more slowly across a gradient of increas- ing simulated environmental variation. Furthermore, higher evenness of elasticity was significantly correlated with a reduced chance of listing as Threatened on the International Union for Conservation of Nature Red List. The relative importance of life-history traits of diverse species can help us infer how natural assemblages will be affected by novel anthropogenic and climatic disturbances.
Keywords: International Union for Conservation of Nature Red List; extinction; life history; stage-based; elasticity; stochasticity
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Lillie 1895 Cell Lineage.pdf
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LEW-MAR
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Lillie Embryology.pdf
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LEW-MAR
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Limits to adaptation
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An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society’s responses to climate change.
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Linked in: Connectiong Riparian areas to support Forest Biodiversity
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Many forest-dwelling species rely on both
terrestrial and aquatic habitat for their
survival. These species, including rare and
little-understood amphibians and arthropods,
live in and around headwater streams and
disperse overland to neighboring headwater
streams. Forest management policies that
rely on riparian buffer strips and structurebased
management—practices meant to
preserve habitat—address only some of
these habitat needs. They generally do not
consider the overland connectivity necessary
for these species to successfully move across
a landscape to maintain genetically diverse
populations.
Management in headwater areas also can
affect downstream salmon habitat. Landslides
and debris flows initiated in these areas can
severely degrade habitat by dumping too
much sediment and not enough large wood
into the stream. Carefully managing sensitive
headwater areas can aid not only amphibians
and arthropods, but also threatened salmon
populations and other forest organisms.
Pacific Northwest Research Station scientists
are exploring scenarios for protecting
headwaters by extending riparian buffers
and connecting them over ridgelines to
neighboring drainages. A range of management
practices designed to achieve multiple
objectives may be appropriate in these
protected areas to facilitate cost-effective,
ecologically integrated management plans.
Headwater links could piggyback on lands
that are already protected and could consider
such factors as sensitivity to debris flows and
landslides, land ownerships and objectives,
and climate change.
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Linking climate change to lemming cycles
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The population cycles of rodents at northern latitudes have puzzled
people for centuries1,2
, and their impact is manifest throughout the
alpine ecosystem2,3
. Climate change is known to be able to drive
animal population dynamics between stable and cyclic phases
4,5
,
and has been suggested to cause the recent changesin cyclic dynamics
of rodents and their predators
3,6–9
. But although predator–rodent
interactions are commonly argued to be the cause of the
Fennoscandian rodent cycles
1,10–13
, the role of the environment in
the modulation of such dynamics is often poorly understood in
natural systems
8,9,14
. Hence, quantitative links between climatedriven
processes and rodent dynamics have so far been lacking.
Here we show that winter weather and snow conditions, together
with density dependence in the net population growth rate, account
for the observed population dynamics of the rodent community
dominated by lemmings (Lemmus lemmus) in an alpine Norwegian
core habitat between 1970 and 1997, and predictthe observed absence
of rodent peak years after 1994. These local rodent dynamics are
coherentwith alpine bird dynamics both locally and over all ofsouthern
Norway, consistent with the influence of large-scale fluctuations
in winter conditions. The relationship between commonly available
meteorological data and snow conditions indicates that changes in
temperature and humidity, and thus conditions in the subnivean
space, seem to markedly affect the dynamics of alpine rodents and
their linked groups. The pattern of less regular rodent peaks, and
corresponding changes in the overall dynamics of the alpine ecosystem,
thusseemslikely to prevail over a growing area under projected
climate change.
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Linking forest fires to lake metabolism and carbon dioxide emissions in the boreal region of Northern Quebec
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Natural fires annually decimate up to 1% of the forested area in the boreal region of Que ́bec, and represent a major structuring force in the region, creating a mosaic of watersheds characterized by large variations in vegetation structure and composition. Here, we investigate the possible connections between this fire-induced watershed heterogeneity and lake metabolism and CO2 dynamics. Plankton respiration, and water–air CO2 fluxes were measured in the epilimnia of 50 lakes, selected to lie within distinct watershed types in terms of postfire terrestrial succession in the boreal region of Northern Que ́ bec. Plankton respiration varied widely among lakes (from 21 to 211lgCL1day1), was negatively related to lake area, and positively related to dis- solved organic carbon (DOC). All lakes were supersaturated in CO2 and the resulting carbon (C) flux to the atmosphere (150 to over 3000 mg C m2 day1) was negatively related to lake area and positively to DOC concentration. CO2 fluxes were positively related to integrated water column respiration, suggesting a biological component in this flux. Both respiration and CO2 fluxes were strongly negatively related to years after the last fire in the basin, such that lakes in recently burnt basins had significantly higher C emissions, even after the influence of lake size was removed. No significant differences were found in nutrients, chlorophyll, and DOC between lakes in different basin types, suggesting that the fire-induced watershed features influence other, more subtle aspects, such as the quality of the organic C reaching lakes. The fire-induced enhancement of lake organic C mineralization and C emissions represents a long-term impact that increases the overall C loss from the landscape as the result of fire, but which has never been included in current regional C budgets and future projections. The need to account for this additional fire-induced C loss becomes critical in the face of predictions of increasing incidence of fire in the circumboreal landscape.
Keywords: boreal, carbon dioxide flux, climate, forest fire, lakes, organic carbon, plankton respiration,
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Linking forest fires to lake metabolism and carbon dioxide emissions in the boreal region of Northern Quebec
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Natural fires annually decimate up to 1% of the forested area in the boreal region of Que ́bec, and represent a major structuring force in the region, creating a mosaic of watersheds characterized by large variations in vegetation structure and composition. Here, we investigate the possible connections between this fire-induced watershed heterogeneity and lake metabolism and CO2 dynamics. Plankton respiration, and water–air CO2 fluxes were measured in the epilimnia of 50 lakes, selected to lie within distinct watershed types in terms of postfire terrestrial succession in the boreal region of Northern Que ́ bec. Plankton respiration varied widely among lakes (from 21 to 211lgCL1day1), was negatively related to lake area, and positively related to dis- solved organic carbon (DOC). All lakes were supersaturated in CO2 and the resulting carbon (C) flux to the atmosphere (150 to over 3000 mg C m2 day1) was negatively related to lake area and positively to DOC concentration. CO2 fluxes were positively related to integrated water column respiration, suggesting a biological component in this flux. Both respiration and CO2 fluxes were strongly negatively related to years after the last fire in the basin, such that lakes in recently burnt basins had significantly higher C emissions, even after the influence of lake size was removed. No significant differences were found in nutrients, chlorophyll, and DOC between lakes in different basin types, suggesting that the fire-induced watershed features influence other, more subtle aspects, such as the quality of the organic C reaching lakes. The fire-induced enhancement of lake organic C mineralization and C emissions represents a long-term impact that increases the overall C loss from the landscape as the result of fire, but which has never been included in current regional C budgets and future projections. The need to account for this additional fire-induced C loss becomes critical in the face of predictions of increasing incidence of fire in the circumboreal landscape.
Keywords: boreal, carbon dioxide flux, climate, forest fire, lakes, organic carbon, plankton respiration, watershed
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Linking primary production, climate and land use along an urban–wildland transect: a satellite view
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Variation of green vegetation cover influences local climate dynamics, exchange of water–heat between land and atmosphere, and hydrological processes. However, the mechanism of interaction between vegetation and local climate change in subtropical areas under climate warming and anthropogenic disturbances is poorly understood. We analyzed spatial–temporal trends of vegetation with moderate-resolution imaging spectroradiometer (MODIS) vegetation index datasets over three sections, namely urban, urban–rural fringe and wildland along an urban–wildland transect in a southern mega-city area in China from 2000–2008. The results show increased photosynthetic activity occurred in the wildland and the stable urban landscape in correspondence to the rising temperature, and a considerable decrease of vegetation activity in the urban–rural fringe area, apparently due to urban expansion. On analyzing the controlling factors of climate change and human drivers of vegetation cover change, we found that temperature contributed to vegetation growth more than precipitation and that rising temperature accelerated plant physiological activity. Meanwhile, human-induced dramatic modification of land cover, e.g. conversion of natural forest and cropland to built-up areas in the urban–rural fringe, has caused significant changes of green vegetation fraction and overall primary production, which may further influence local climate.
Keywords: vegetation greenness, environmental gradients, urban, transect, climate change, remote sensing, rural
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