Plant Community Responses to Global Change Drivers

Global change will alter resources, which are predicted to change the composition and functioning of plant communities. Here, I present the results of several projects studying plant community changes in response to resource manipulations. First, I present data from an experiment at Konza Prairie Biological Station in Manhattan Kansas. In this experiment, nutrient additions (nitrogen and phosphorus) turned the tallgrass prairie from being dominate by C4 grasses to C3 forbs. Next, I detail plant community responses to resource manipulations across ~100 experiments world-wide. This data synthesis found that when 5 factors are simultaneously manipulated, there are drastic changes in the plant community. Additionally, the greater number of factors that are manipulated, the greater the change in productivity. Lastly, I review my current postdoctoral work, focused on developing new ways to study patterns of community change using rank abundance curves.


Photo of the phosphorus plots experiment at Konza Prairie Biological Station. Photo Credit: Melinda Smith

Challenges of scale when examining plant-interactions in arid ecosystems: micro, local, & regional [Wed. May 18]

In high stress environments, such as deserts, positive interactions among plants maintain biodiversity and productivity.  However, the role and mechanism of these positive interactions changes depending on the context of spatial scale.
I will discuss how positive plant-interactions in deserts change at the micro, local, and regional scale.  I also discuss the challenges associated with examining plant interactions at different spatial scales as a researcher, such as sampling techniques, community structure, and interacting factors.
Typically studies examining positive plant-interactions focus on local gradients, thereby neglecting micro or regional scales.  All spatial scales share similarities in that each have gradients that modifies the mechanism, magnitude, and direction of plant interactions.  Drawing parallels among different spatial scales and considering all three simultaneously as a response surface can provide a better understanding of positive interactions.  This can assist conservation biologist and restoration ecologists make better informed decisions when managing desert ecosystems in support of global biodiversity.

Alex Filazzola
PhD Student
York University
Toronto, Canada