-
Genetic diversity in widespread species is not congruent with species richness in alpine plant communities
-
The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation plan- ning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.
Keywords
alpine vascular plants, Alps, biodiversity conservation, Carpathians, genetic diversity, species richness.
Located in
Resources
/
Climate Science Documents
-
How does climate change influence demographic processes of widespread species? Lessons from the comparative analysis of contrasted populations of roe deer
-
How populations respond to climate change depends on the interplay between life history, resource avail- ability, and the intensity of the change. Roe deer are income breeders, with high levels of allocation to reproduction, and are hence strongly constrained by the availability of high quality resources during spring. We investigated how recent climate change has influenced demographic processes in two populations of this widespread species. Spring began increasingly earlier over the study, allowing us to identify 2 periods with contrasting onset of spring. Both populations grew more slowly when spring was early. As expected for a long-lived and iteroparous species, adult survival had the greatest potential impact on population growth. Using perturbation analyses, we measured the relative contribution of the demographic parameters to observed variation in population growth, both within and between periods and populations. Within peri- ods, the identity of the critical parameter depended on the variance in growth rate, but variation in recruit- ment was the main driver of observed demographic change between periods of contrasting spring earliness. Our results indicate that roe deer in forest habitats cannot currently cope with increasingly early springs. We hypothesise that they should shift their distribution to richer, more heterogeneous landscapes to offset energetic requirements during the critical rearing stage.
Keywords
Age-structured populations, demographic change, income breeding, perturbation analysis, population growth, Recruitment, Stochastic environment, Survival.
Located in
Resources
/
Climate Science Documents
-
Global shifts towards positive species interactions with increasing environmental stress
-
The study of positive species interactions is a rapidly evolving field in ecology. Despite decades of research, controversy has emerged as to whether positive and negative interactions predictably shift with increasing environmental stress as hypothesised by the stress-gradient hypothesis (SGH). Here, we provide a synthesis of 727 tests of the SGH in plant communities across the globe to examine its generality across a variety of ecological factors. Our results show that plant interactions change with stress through an outright shift to facilitation (survival) or a reduction in competition (growth and reproduction). In a limited number of cases, plant interactions do not respond to stress, but they never shift towards competition with stress. These findings are consistent across stress types, plant growth forms, life histories, origins (invasive vs. native), climates, ecosystems and methodologies, though the magnitude of the shifts towards facilitation with stress is dependent on these factors. We suggest that future studies should employ standardised defini- tions and protocols to test the SGH, take a multi-factorial approach that considers variables such as plant traits in addition to stress, and apply the SGH to better understand how species and communities will respond to environmental change.
Keywords
Biotic interactions, community ecology, ecosystems and climates, environmental stress, facilitation, invasive species, meta-analysis, plant traits, the stress-gradient hypothesis.
Located in
Resources
/
Climate Science Documents
-
Persistent reduced ecosystem respiration after insect disturbance in high elevation forests
-
Amid a worldwide increase in tree mortality, mountain pine beetles (Dendroctonus ponderosae Hopkins) have led to the death of billions of trees from Mexico to Alaska since 2000. This is predicted to have important carbon, water and energy balance feedbacks on the Earth system. Counter to current projections, we show that on a decadal scale, tree mortality causes no increase in ecosystem respiration from scales of several square metres up to an 84 km2 valley. Rather, we found comparable declines in both gross primary productivity and respiration suggesting little change in net flux, with a transitory recovery of respiration 6–7 years after mortality associated with increased incorporation of leaf litter C into soil organic matter, followed by further decline in years 8–10. The mechanism of the impact of tree mortality caused by these biotic disturbances is consistent with reduced input rather than increased output of carbon.
Keywords
Carbon balance, disturbance, ecosystem respiration, gross primary productivity, insect outbreak, lodgepole pine, mountain pine beetle, mountain West, subalpine forest.
Located in
Resources
/
Climate Science Documents
-
Alleles underlying larval foraging behaviour influence adult dispersal in nature
-
The dispersal and migration of organisms have resulted in the colonisation of nearly every possible habitat and ultimately the extraordinary diversity of life. Animal dispersal tendencies are commonly heterogeneous (e.g. long vs. short) and non-random suggesting that phenotypic and genotypic variability between individuals can contribute to population-level heterogeneity in dis- persal. Using laboratory and field experiments, we demonstrate that natural allelic variation in a gene underlying a foraging polymorphism in larval fruit flies (for), also influences their dispersal tendencies as adults. Rover flies (forR; higher foraging activity) have consistently greater dispersal tendencies and are more likely to disperse longer distances than sitter flies (fors; lower foraging activity). Increasing for expression in the brain and nervous system increases dispersal in sitter flies. Our study supports the notion that variation in dispersal can be driven by intrinsic variation in food-dependent search behaviours and confirms that single gene pleiotropic effects can contrib- ute to population-level heterogeneity in dispersal.
Located in
Resources
/
Climate Science Documents
-
Rapid growth in CO2 emissions after the 2008–2009 global financial crisis.pdf
-
1st paragraph: Global carbon dioxide emissions from fossil-fuel combustion and cement production grew 5.9% in 2010, surpassed 9 Pg of carbon (Pg C) for the first time, and more than offset the 1.4% decrease in 2009. The impact of the 2008–2009 global financial crisis (GFC) on emissions has
been short-lived owing to strong emissions growth in emerging economies, a return to emissions growth in developed economies, and an increase in the fossil-fuel intensity of the world economy.
Located in
Resources
/
Climate Science Documents
-
Citizen Involvement in the U.S. Endangered Species Act
-
Data on listed species refute critiques of citizen involvement in the U.S. Endangered Species Act.
Located in
Resources
/
Climate Science Documents
-
Elevated Eocene Atmospheric CO2 and Its Subsequent Decline
-
Closing paragraph: Estimates of early Eocene atmospheric CO2 from Green River sodium carbonates are in the same range as those predicted by geochemical models (7). By È20 Ma, all available data (8) suggest ECO2^atm was at or near modern concentrations.
Located in
Resources
/
Climate Science Documents
-
The False Spring of 2012, Earliest in North American Record
-
2nd paragraph: As global climate warms, increasingly warmer springs may combine with the random climatological occurrence of advective freezes, which result from cold air moving from one region to another, to dramatically increase the future risk of false springs, with profound ecological and economic consequences [e.g., Gu et al., 2008; Marino et al., 2011; Augspurger, 2013]. For example, in the false spring of 2012, an event embedded in long-term trends toward earlier spring [e.g., Schwartz et al., 2006], the frost damage to fruit trees totaled half a billion dollars in Michigan alone, prompting the federal government to declare the state a disaster area [Knudson, 2012].
Located in
Resources
/
Climate Science Documents
-
The Latest on Volcanic Eruptions and Climate
-
2nd paragraph: It is well known that large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with a life- time of several months to about 2 years. The radiative effects of these aerosol clouds produce global cooling and are an important natural cause of climate change. Regional responses include winter warming of Northern Hemisphere continents and weakening of summer Asian and African monsoons. Even though there has not been a large eruption since the eruption of Mount Pinatubo in the Philippines on 15 June 1991, research contin- ues to produce interesting results.
Located in
Resources
/
Climate Science Documents
