Tag Archives: ecology

connectivity and corridors

From Conservation Biology:

Connecting science, policy, and implementation for landscape-scale habitat connectivity

In an increasingly fragmented world, networks of habitat corridors are critical to support movement of organisms between habitat patches and the long-term persistence of species. The science of corridor design and the policy of corridor establishment are developing rapidly, but often independently. Here we assess the links between the science and policy of habitat corridors, to better understand how corridors can be effectively implemented, with a focus on a suite of landscape-scale connectivity plans in tropical and sub-tropical Asia. Our synthesis suggests that the process of corridor designation may be more efficient if the scientific determination of optimal corridor locations and arrangement is synchronized in time with the achievement of political buy-in and policy direction for corridor designation. Land tenure and the intactness of existing habitat in the region are also critical factors –optimal connectivity strategies may be very different if there are few, versus many, political jurisdictions (including commercial and traditional land tenures) and intact versus degraded habitat between patches. We identify financing mechanisms for corridors, and also several important gaps in our understanding of effective corridor design including how corridors, particularly those managed by local communities, can be protected from habitat degradation and unsustainable hunting. Finally, we point to a critical need for quantitative, data-driven models that can prioritize potential corridors or multi-corridor networks based on their relative contributions to long-term metacommunity persistence.

the case of the missing mammals

Where would the large mammals be if humans hadn’t come along?

How would the world look if humans had never spread out across the Earth? For a start, we’d have a lot more forest, much less pollution, and the stars would look unbelievably bright. But, as a new map shows, the planet would also be absolutely teeming with large mammals, from the Serengeti to Northern Europe and all the way across the Americas. Researchers at Denmark’s Aarhus University have created a global map which shows the distribution of large mammals as it may have been if humans had never left Africa…

The Americas used to be home to 105 large mammal species, including sabre-toothed cats, mastodons, giant sloths and giant armadillos, which all disappeared in the last 100,000 years or so. A previous study by the Aarhus University research team showed that human activity was responsible for this mass extinction…

“The reason that many safaris target Africa is… that it’s one of the only places where human activities have not yet wiped out most of the large animals,” said Postdoctoral Fellow Søren Faurby, lead author on the study.

The highest levels of diversity would be in central regions of north and south America, especially parts of Texas, the U.S. Great plains and regions of Brazil and Argentina.

Unnatural Selection

Amazon description:

Gonorrhea. Bed bugs. Weeds. Salamanders. People. All are evolving, some surprisingly rapidly, in response to our chemical age. In Unnatural Selection, Emily Monosson shows how our drugs, pesticides, and pollution are exerting intense selection pressure on all manner of species. And we humans might not like the result.

Monosson reveals that the very code of life is more fluid than once imagined. When our powerful chemicals put the pressure on to evolve or die, beneficial traits can sweep rapidly through a population. Species with explosive population growth—the bugs, bacteria, and weeds—tend to thrive, while bigger, slower-to-reproduce creatures, like ourselves, are more likely to succumb.

Monosson explores contemporary evolution in all its guises. She examines the species that we are actively trying to beat back, from agricultural pests to life-threatening bacteria, and those that are collateral damage—creatures struggling to adapt to a polluted world. Monosson also presents cutting-edge science on gene expression, showing how environmental stressors are leaving their mark on plants, animals, and possibly humans for generations to come.

more on automated data synthesis

Here’s another article from Environmental Modeling and Software about automated synthesis of scattered research results:

We describe software to facilitate systematic reviews in environmental science. Eco Evidence allows reviewers to draw strong conclusions from a collection of individually-weak studies. It consists of two components. An online database stores and shares the atomized findings of previously-published research. A desktop analysis tool synthesizes this evidence to test cause–effect hypotheses. The software produces a standardized report, maximizing transparency and repeatability. We illustrate evidence extraction and synthesis. Environmental research is hampered by the complexity of natural environments, and difficulty with performing experiments in such systems. Under these constraints, systematic syntheses of the rapidly-expanding literature can advance ecological understanding, inform environmental management, and identify knowledge gaps and priorities for future research. Eco Evidence, and in particular its online re-usable bank of evidence, reduces the workload involved in systematic reviews. This is the first systematic review software for environmental science, and opens the way for increased uptake of this powerful approach.

connectivity and corridors

From Conservation Biology, here’s an article on connectivity and movement corridor models for wildlife:

Habitat corridors are important tools for maintaining connectivity in increasingly fragmented landscapes, but generally they have been considered in single-species approaches. Corridors intended to facilitate the movement of multiple species could increase persistence of entire communities, but at the likely cost of being less efficient for any given species than a corridor intended specifically for that species. There have been few tests of the trade-offs between single- and multispecies corridor approaches. We assessed single-species and multispecies habitat corridors for 5 threatened mammal species in tropical forests of Borneo. We generated maps of the cost of movement across the landscape for each species based on the species’ local abundance as estimated through hierarchical modeling of camera-trap data with biophysical and anthropogenic covariates. Elevation influenced local abundance of banded civets (Hemigalus derbyanus) and sun bears (Helarctos malayanus). Increased road density was associated with lower local abundance of Sunda clouded leopards (Neofelis diardi) and higher local abundance of sambar deer (Rusa unicolor). Pig-tailed macaque (Macaca nemestrina) local abundance was lower in recently logged areas. An all-species-combined connectivity scenario with least-cost paths and 1 km buffers generated total movement costs that were 27% and 23% higher for banded civets and clouded leopards, respectively, than the connectivity scenarios for those species individually. A carnivore multispecies connectivity scenario, however, increased movement cost by 2% for banded civets and clouded leopards. Likewise, an herbivore multispecies scenario provided more effective connectivity than the all-species-combined scenario for sambar and macaques. We suggest that multispecies habitat connectivity plans be tailored to groups of ecologically similar, disturbance-sensitive species to maximize their effectiveness.