Graduate Student - Daniel S. Song [cv]songdan [at] sas [dot] upenn [dot] edu
I'm now a 2nd year grad student in the eco-evo program. This is an excerpt from a description of my research interests.
The stark reality of human activity is the drastic rate of species loss and altered ecosystem functioning (1). Humans rely on ecosystem goods and services: pollination, sustenance, and countless others for our well-being (2). Alarming trends in the perturbation of ecosystems by anthropogenic activity have driven ecologists to examine its effect on ecosystem functioning (3). One area of intense interest is the relationship between biodiversity and ecosystem functioning (BEF). The BEF hypothesis posits that decreases in biodiversity will result in corresponding decreases ecosystem functioning, which is defined here as the combination of processes, properties, and maintenance of both (4).
Advances in BEF research now lead ecologists to focus not on whether biodiversity affects ecosystem functioning but how it affects it (5). There is also a shift in focus away from phylogenetic diversity towards functional trait diversity. The “biological insurance” hypothesis relates functional traits and biodiversity (6). It states that the biodiversity loss causes voids in function and is detrimental to ecosystems. Functional traits are critical, quantifiable components of ecosystems that help us to understand functioning. While considerable attention has been paid to single trophic levels, vertical linkages between levels have been overlooked (7). Furthermore, not much is known about the role plant-pollinator networks in maintaining ecosystem services. I propose to examine how anthropogenic activities affect plant and pollinator assemblages and the interaction between them.
The International Long Term Ecological Research (ILTER) site at Lake Hövsgöl, Mongolia is the ideal system in which to conduct my graduate research for several reasons:  Northern Mongolia is predicted to see some of the largest increases in temperature worldwide and has already experienced a significant increase, Fig. 1.  There is increased grazing pressure due to changes in the behavior of nomadic herders. In Mongolia, nomadic herding is an important source of disturbance and is a practice that spans centuries. In the past, herders have roamed the steppe grasslands, visiting different grazing lands. But recently, herders have become more sedentary.  Lastly, at the ILTER site there is an interesting ecological boundary where taiga forests and steppe grasslands come together.
My aim is to establish basic understanding of plant and pollinator networks and their functional traits in northern Mongolia. I will investigate how change in grazing patterns and climate are altering functional characteristics of pollinator and plant assemblages.
(1) Vitousek, P. M. et al. Science. 277, 494 (1997). (2) Daily, G. C. Washington, DC: Island Press (1997). p. 3. (3) Hopper, D. U. et al. Ecol. Monogr. 75(1), 3-35 (2005). (4) Naeem, S. and J. P. Wright. Ecol. Lett. 6, 567-579 (2003). (5) Rosenfeld, J. S. Conserv. Biol., 16, 837-839 (2002). (6) Folke, C. et al. Ecol. Appl. 6(4), 1018-1024 (1996). (7) Reiss. J. et al. Trends. Ecol. Evolut. 24(9), 505-514 (2009).