Global climate change is causing multifaceted changes to earth's ecosystems. Many studies have examined the influences of changing temperature, water, and CO2 on community and ecosystem-wide dynamics. We are also starting to understand how the increasing frequency and intensity of extreme weather events, such as hurricanes, on communities and ecosystems. These studies have greatly improved our predictions about the ecological consequences of global climate change, leading to greater parameterization of predictive models. However, winter snowstorms are also changing and there has been less research empirically assessing how ecological communities and/or the ecosystems in which they are embedded respond to these changes. In the NE coast of the United States, the frequency of winter storms has remained constant, but their intensity has been increasing, likely as a consequence of climate change. Moreover, temperatures are generally increasing during the winter in this region in between these intense storms. We are studying these dynamics in the largest forest reserve on the East Coast of the United States-the NJ Pinelands Preserve. Specifically, we are assessing the short-term shifts in community composition and abundance while starting a longer term study of broader ecosystem consequences.
Results/Conclusions
The NJ Pine Barrens are characterized by a lack of detritus on the forest floor. We observed a sharp increase in fine woody detritus after intense winter storms in 2018. The following spring, we conducted an experiment to assess variation in arthropod community structure in response to this influx in fine woody detritus. We set up 6 blocks of three 5 x 5m plots which were randomly assigned to control, removal and supplement treatments. In removal plots, we manually removed all fine woody detritus. The fine woody detritus was transferred to the supplemented plots within the same block. We maintained these treatments every 2 weeks until November 2018 and then only after winter storms. We collected arthropods using Winkler sifters monthly from May (before treatment application) to November. We found that arthropod abundance increased by >200% in supplemented plots compared to removal plots. In contrast, family richness and the abundance of the most common families peaked in control plots. Overall, species composition varied significantly across the three plot types (PerMANOVA, P<0.05), with Collembola and ants contributing the most to differences in family-level composition. We will continue this experiment over longer time periods to further assess changing community dynamics and to examine changes in ecosystem-wide processes, such as nutrient cycling and decomposition.