Strategies for Preventing Climate Change Induced Extinction

by Alexander Birk

Climate change is an increasingly problematic obstacle in slowing the rate of species extinction and has been widely accepted as the major threat to biodiversity. With this threat rising, there needs to be a better strategy to protect species. Identifying a species as in danger of extinction is the key to saving them, the current system to detect potential extinctions does not give enough time to effectively save some species once they have been deemed endangered. According to Stanton et al. (2014) it would be much more effective to put species into more specific categories leading up to extinction. This would allow for a more visible pattern of endangerment over the years leading to a trajectory of where the species is headed. Stanton et al. (2014) Continue reading

Analyzing the Vulnerability of Rainforest Birds to Deforestation

by Maithili Joshi

In South East Queensland, Australia Pavlacky et al.(2014) conducted a study on the vulnerability of birds, rainforest ecosystems, and the biological impacts in response to deforestation in local and regional areas. The central idea is the to investigate the life history and forest structure to rank the vulnerability of avian species, while also looking at species loss along different kinds of forest structure and landscape change. The objectives are evaluating the effects of life history traits on the patch occupancy and vulnerability of rainforest birds, determining the relative effects of stand, landscape, and patch structure on species richness, and evaluating the relative contributions of deforestation and fragmentation to species richness. Continue reading

Effects of Alternative sets of Climate Predictors on Species Distribution Models and Estimates of Extinction Risk

by Kyle Jensen

As arid ecosystems have been recognized as being especially sensitive to climate change, they thus provide an appropriate system to assess the use of SDMs in estimating the threat of climate change to various species. Species distribution models (SDMs) can quantify relationships between species and environmental factors, and use this data to predict spatial distributions. SDMs are thus widely used to derive projections of species distribution under conditions of climate change. These models are correlative however, and as such are unable to identify causal species-environment relationships. They can only be used as supporting evidence for an existing hypothesis on factors affecting species distribution; as such the factors must be chosen as inputs for the SDM to function. Identifying the important climatic factors involved in determining the range of a given species is a key factor in assessing the potential effects of climate change on species distribution and extinction risk. Little research however has been done investigating the effects using alternative sets of climate predictor variables may have on the projections of SDMs. Pliscoff et al (2014) seek to examine this area of potential uncertainty, addressing the potential variability of SDM spatial projections and determination of extinction risks through the creation and analysis of several sets of environmental predictors. They found that by adjusting climate predictor variables they were able to significantly affect predictions of spatial distribution as well as, for the first time, extinction risk estimates. This implies greater variability in such studies than previously thought. Continue reading

The Endangered Species Act: Conservation-Reliant Species

by Alexander Birk

The United States Endangered Species Act (ESA) is responsible for the protection of species and their habitats. The ESA maintains a list of the species at risk; the ultimate goal is to get these species off of the list. In order to get an endangered species removed (delisted) the ESA must regard that species as self-sustaining. The definition of a self-sustaining species becomes difficult as the ESA looks at conservation-reliant species. A conservation-reliant species is defined as a species that has been delisted; however it requires management in order to prevent it from once again being at risk. Continue reading

Comets, Climate Change, and Extinctions—2

 

by Emil Morhardt

When a large meteorite struck the earth 65 million years ago, it killed off the dinosaurs by abrupt climate change; the energy of the strike sharply raised global temperatures, ignited massive wildfires, and filled the atmosphere both with smoke from the fires and dust ejected from the crater which presumably prevented plants from thriving for a long enough time to starve all but the smallest animals (allowing, as it happened, the evolution of humans.) That’s a different cause of climate change than now, and most of us, if we worry about climate change at all, don’t much worry about it being caused by another meteorite strike. But, on August 16, I wrote about a paper published in 2007 that proposed a similar, though not so severe, extraterrestrial impact and abrupt climate change about 12,800 years ago—the initiation of the Younger Dryas (YD) cooling episode that stopped the Continue reading

Disequilibrium between Tree Species Distributions and Regional Temperatures

by Cortland Henderson

Correlations between geographic distributions of plant species and the current climate have been identified, suggesting that species ranges will shift upwards if global temperatures rise. These links, however, are based on models that do not establish whether or not plant species are at equilibrium with the current climate, and are incapable of differentiating between naturally occurring shifts and climate-induced shifts. García-Valdés et al. (2013) examine the ten most common tree distributions throughout the Iberian Peninsula by creating a new species distribution model that relaxes built-in assumptions that tree species and climate are currently at equilibrium. Their model successfully removed previous biases and found that tree species are not at equilibrium Continue reading

Mass-flowering Crops Positively Affect Wild Bee Brood Numbers

 

by Lia Metzger

The expansion of mass-flowering crops has been linked to the loss of biodiversity of farmlands because they escape into natural and semi-natural habitats. However, these mass-flowering crops have a higher density of flowers than non-crop species, and thus produce more food resources with more access to nectar and pollen, so they may enhance the abundance of wild foraging bees. Holzschuh et al. (2013) investigated how oilseed rape, a mass-flowering crop, affects the abundance of the solitary and polylectic Red Mason Bee Osmia bicornis, a generalist bee species that nests in both natural and semi-natural habitats. Using data from 67 sites in Germany, they compared the abundance of Osmia bicornic in grasslands adjacent to oilseed rape fields and isolated from oilseed rape fields and vice versa. Artificial nests were assessed for Continue reading