"Forest restoration" is a common conservation theme, often promoted as a means of repairing degraded landscapes and boosting carbon storage. But when the planting areas are poorly chosen, these initiatives have the potential to eradicate ancient grasslands, with devastating effects on biodiversity and ecosystem services. In Episode #5 of BioScience Talks, Joseph Veldman of Iowa State University describes the millions of acres of grassy biomes currently under threat from forestation and the efforts under way to protect them.

Human-caused fires have the potential to hugely alter tropical forests—and the world at large. In this episode, we talk to Dr. Jennifer Balch, of the University of Colorado–Boulder. She discusses a long-term experiment in which she and her team deliberately lit fires in the Brazilian Amazon, with the aim of simulating the fires that are often released when people use burning to clear land. The forests were resilient to initial burning, but when a major drought hit in 2007, things changed quickly. The combined effects of drought and fire have huge implications, from grassland incursion and climate change to rainforest loss at previously unmeasured levels.

The article is part of a BioScience Special Section on Tropical Forest Responses to Large-Scale Experiments.

Extracellular vesicles (EVs; article here) are one of the biggest stories in biology. These tiny "packets" are released by cells and constitute a previously misunderstood means of intracellular communication -- and their implications are huge. In humans, EVs can reveal disease, including some cancers and viral infections, and EV technology may soon replace many tissue biopsies. In addition, vesicles can be loaded with targeted treatments for a variety of diseases. The role that EVs will play in medicine is only beginning to be understood.

In this episode, I'm joined by Drs. Xandra Breakefield and Mikolaj Zaborowski, two Harvard Medical School researchers working at the forefront of the field.

Fast-growing transgenic salmonids are currently being developed for eventual human consumption. Dr. Robert Devlin and his team seek to evaluate the ecological threats posed by these GMO fish. In this discussion, he outlines the uncertainty inherent in these risk assessments and explains areas of potential future study. Read the full article: http://io.aibs.org/devful

In our first episode, we discuss the concept of coupled human and natural systems (CHANS) with Dr. Jiquan Chen, of Michigan State University, who studies CHANS on the Mongolian Plateau. The CHANS concept enables the quantification of interacting human and biophysical factors, which can help shed light on how these systems work.

This episode previews BioScience Talks' upcoming first episode on coupled human and natural systems, to be released on 10 June. Stay tuned!