Scientists around the world are collaborating to understand how deforestation, climate change, and natural processes will interact to affect one of the most productive and biodiverse ecosystems on Earth. Researchers have measured the effects of periodic forest fires on primary productivity in Amazon rain forest plots, comparing years with average precipitation and years with severe drought. Propose which controls would be necessary for such studies.

Video transcript

Hi everyone. Let's look at the next problem. It says there is significant reduction the biodiversity of tropical rainforests. The main drivers of tropical forests and biodiversity loss are and as we look over the answer choices, we notice that choice D is all of the answers above are correct. So we have the possibility that there's more than one correct answer. So choice A says deforestation and fragmentation. Um let's recall that fragmentation is when instead of having a long continuous um forest environment deforestation has led to fragmentation where you have um parts isolated from each other um broken up by areas of deforestation instead of being continuous so animals can no longer cross over easily um from one spot of rain forest to another. And deforestation and fragmentation are major causes of biodiversity loss remarked that since we could have more than one correct since the beginning of the 20th century, almost half of the tropical forest that was present at the beginning of the century has disappeared. So that's been a major driver of biodiversity loss. Choice B says invasion by species and yes, invasive species um have been a driver of biodiversity loss. They cause extinction by competing for resources and changing habitats. So we'll mark that as a possible correct answer. And then finally, see the changing climate. Um the changing climate has caused increased destruction in the rainforest by increasing the intensity and frequency of natural disasters like fires, um droughts that kill off trees in the forest and then caused this loss of biodiversity cause the loss of the animals that depend on those trees. So this is also correct. So our answer is D All of the answers above. Oops. All of the answers above are correct. So the main drivers of tropical forest biodiversity loss are Choice D. All of the above deforestation and fragmentation, invasion by species and the changing climate. See you in the next video.