No return of diversity?

In the past few decades, there has been an increasing concern and therefore research into the eutrophication of natural ecosystems caused by high levels of nitrogen addition. Some studies, such as Foster and Gross 1998 and Clark and Tilman 2008 (among others), have shown that nitrogen fertilization leads to a decrease in the diversity of communities. However, the long-term consequences of these actions are not well understood. How quickly do the nitrogen … Continue reading

All I Really Need to Know, I Learned from Aphids

In our lab, we throw around the terms “eco-evolutionary dynamics” or “eco-evolutionary feedbacks” pretty loosely to describe any interactions between ecological and evolutionary processes (two more terms that are defined pretty abstractly). But we can do a better job of defining eco-evolutionary feedbacks, and a recent paper by Martin Turcotte, Dave Reznick, and Daniel Hare reminded me of that. This is another paper from the Eco-Evo special feature in The … Continue reading

Parasitism Threatens Mutualism

Background: The world is a complicated place. Organisms typically interact with one another simultaneously and the strength of interactions can depend on what’s happening in the environment. As a number of organisms within a community increases, indirect interactions also increase exponentially (Abrahams 1992). As ecologists, we’re fascinated by the beauty of this complex world while we struggle to understand and predict how nature really works. Studying a pair-wise interaction is … Continue reading

Are invaders bigger and better in their introduced ranges?

It is hypothesized that invasive species are doing something fundamentally different in their introduced ranges – they seem to grow faster and larger, spread more aggressively, and outcompete native species, lowering biodiversity. However, these assumptions have surprisingly little evidence to back them up. In my last post, I wrote about Powell et al. 2013’s article, that found invaders may not be as bad for native biodiversity as we think. In … Continue reading

Changing world, changing interactions

When I think of how a species might be affected by global change, I tend to focus first on the abiotic: distribution maps predicting species range shifts based on temperature and precipitation come to mind. But obviously it’s more complicated than that—global change is bound to affect biotic factors as well, particularly interactions between species. This makes predicting the consequences of global change more complicated. If species A interacts with … Continue reading

Evolution isn’t so simple

To steal a line from the paper that I’m about to talk about: “Herbivores have fed on plants for more than 400 million years”. I thought this was a pretty striking way to start a paper; it suggests that these interactions might play a really important role in how plants and herbivores evolve. And indeed countless papers have discussed the effects of herbivores in driving the evolution of plant defenses … Continue reading

An Ecological Approach to Invasion Resistance – Insights from the World of Fashion

Old fashions are often recycled by new generations of young people attempting to stand out and be unique (just like everyone else!). Bell bottomed jeans, the paragon of 1970s fashion, saw a (thankfully brief) resurgence in the late 1980s. More recently, the leg warmers and popped collars of the 1980s were suddenly cool again. Strangely enough, ideas in ecology often reappear on a similar 15-20 year cycle. In the case … Continue reading

Adaptive Radiation Constrained By Niche Availability

Understanding why there are so many species is an essential question in biology that continues to generate considerable curiosity and drive evolutionary research. Moreover, people seek to understand how species that are closely related can reside in very different niches and co-occur in areas. Darwin observed such an adaptive radiation with finches in the Galapagos, where the species of birds differ in the size and shape of their beaks, allowing … Continue reading

Trade-offs are important for promoting diversity, even for microbes

Background In 2005, Science Magazine published a special issue exploring 125 big unanswered questions in science in celebration of their 125th anniversary. One of the questions that I keep thinking about (as many biologists do, I’m sure), is this question of, “what determines species diversity?“. I know: This is an overwhelmingly big and important question in biology. So I decided to focus on just one hypothesis addressing this question. That … Continue reading

Guilty as charged? Invasive species may not be that bad for biodiversity

Invasive species are accused of being one of the major causes of modern species extinctions and biodiversity loss, on par with climate change and habitat destruction. A few charismatic examples implicate invasive predators and disease in native species extinctions. For example, the brown tree snake (Boiga irregularis), introduced to Guam in 1952, is implicated in the extinction of 9 of the 11 forest bird species, 5 of which were endemic … Continue reading