18 January 2018

Rainforests: The Year in Review 2017


2017 was a rough year for tropical rainforests, but there were some bright spots.  This is Mongabay’s annual year-in-review on what happened in the world of tropical rainforests, summarizing some of the more notable developments and trends for tropical forests in 2017.

Read More: https://news.mongabay.com/2018/01/rainforests-the-year-in-review-2017/

Forests Have Another Climate-Protection Superpower

Scientists looked at reactive gases emitted by trees and other vegetation, finding they have an overall cooling effect on the atmosphere globally. As forests are cleared, emissions of these cooling reactive gases are reduced. The researchers estimate the loss of this function this may contribute 14 percent towards deforestation-caused global warming. The authors write that effective climate policies will require a “robust understanding” of the relationship between land-use change like deforestation and climate, and urge more research be done toward this goal.

Read More: https://news.mongabay.com/2018/01/study-reveals-forests-have-yet-another-climate-protection-superpower/

Artificial Barriers Prevent Genetic Recovery of Small Isolated Populations of a Low-Mobility Freshwater Fish


"Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45–120 years ago. We found evidence of small-scale (<13 km) genetic structure within reaches unimpeded by barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (FST = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (<100). Our study highlights that, in structured populations, the ability to detect short-term genetic effects from barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies."

Read More: https://www.nature.com/articles/s41437-017-0008-3

Contribution of Predators and Scavengers to Human Well-Being

IUCN global distribution of some species that are known to provide important services to humans over some portion of their range.

Abstract: "Predators and scavengers are frequently persecuted for their negative effects on property, livestock and human life. Research has shown that these species play important regulatory roles in intact ecosystems including regulating herbivore and mesopredator populations that in turn affect floral, soil and hydrological systems. Yet predators and scavengers receive surprisingly little recognition for their benefits to humans in the landscapes they share. We review these benefits, highlighting the most recent studies that have documented their positive effects across a range of environments. Indeed, the benefits of predators and scavengers can be far reaching, affecting human health and well-being through disease mitigation, agricultural production and waste-disposal services. As many predators and scavengers are in a state of rapid decline, we argue that researchers must work in concert with the media, managers and policymakers to highlight benefits of these species and the need to ensure their long-term conservation. Furthermore, instead of assessing the costs of predators and scavengers only in economic terms, it is critical to recognize their beneficial contributions to human health and well-being. Given the ever-expanding human footprint, it is essential that we construct conservation solutions that allow a wide variety of species to persist in shared landscapes. Identifying, evaluating and communicating the benefits provided by species that are often considered problem animals is an important step for establishing tolerance in these shared spaces."

Read More: https://www.nature.com/articles/s41559-017-0421-2