Transforming ecological science at primarily undergraduate institutions through collaborative networks

Ecologists at primarily undergraduate institutions (PUIs) are well positioned to form collaborative networks and make transformative contributions to the study and teaching of ecology. The spatial and temporal complexity of ecological phenomena rewards a collaborative research approach. A network of PUI ecologists can incorporate closely supervised data collection into undergraduate courses, thereby generating data across spatial gradients to answer crucial questions. These data can offer unprecedented insight into fine-and large-scale spatial processes for publications, resource management, and policy decisions. Undergraduate students benefit from the collaborative research experience as they gain experiential learning in team building, project design, implementation, data collection, and analysis. With appropriate funding, collaborative networks make excellent use of the intellectual and experiential capital of PUI faculty for the benefit of science, pedagogy, and society. © 2011 by American Institute of Biological Sciences. All rights reserved

Stoichiometry of soil enzyme activity at the global scale

Extracellular enzymes are the proximate agents of organic matter decomposition and measures of these activities can be used as indicators of microbial nutrient demand. We conducted a global-scale meta-analysis of the seven-most widely measured soil enzyme activities, using data from 40 ecosystems. The activities of β-1,4-glucosidase, cellobiohydrolase, β-1,4-N-acetylglucosaminidase and phosphatase g−1 soil increased with organic matter concentration; leucine aminopeptidase, phenol oxidase and peroxidase activities showed no relationship. All activities were significantly related to soil pH. Specific activities, i.e. activity g−1 soil organic matter, also varied in relation to soil pH for all enzymes. Relationships with mean annual temperature (MAT) and precipitation (MAP) were generally weak. For hydrolases, ratios of specific C, N and P acquisition activities converged on 1 : 1 : 1 but across ecosystems, the ratio of C : P acquisition was inversely related to MAP and MAT while the ratio of C : N acquisition increased with MAP. Oxidative activities were more variable than hydrolytic activities and increased with soil pH. Our analyses indicate that the enzymatic potential for hydrolyzing the labile components of soil organic matter is tied to substrate availability, soil pH and the stoichiometry of microbial nutrient demand. The enzymatic potential for oxidizing the recalcitrant fractions of soil organic material, which is a proximate control on soil organic matter accumulation, is most strongly related to soil pH. These trends provide insight into the biogeochemical processes that create global patterns in ecological stoichiometry and organic matter storage