EnvironmentalManagemtn

A research technician samples greenhouse gases on the KBS LTER Main Cropping Systems Experiment Kurt Stepnitz

ConsumersExpress

Late fall switchgrass harvest at the GLBRC / KBS LTER biofuels scale-up site; Photo Credit: J.E.Doll, Michigan State University J.E. Doll- Michigan State University

Big_Data

Organ Mountains-Desert Peaks National Monument Curtis Monger

Groundwater_Recharge

Researchers conduct fieldwork in the Chihuahuan Desert of New Mexico. ASU

Connectivity

Connectivity modifying structures (ConMods) trap and retain wind-transported seeds and organic material, reducing connectivity and facilitating local recruitment. Jornada LTER

Insight_Into_Veg_Change

2004 mesquite dunelands without grasses and 2008 mesquite dunelands with perennial grasses. Jornada LTER

songbird pops

Hubbard Brook researchers have been studying bird populations for over 50 years. This graph shows the number of birds breeding on a 10-hectare forest plot from 1969-2013. Neotropical migrants show a marked decline early in the record, followed by a stabilization of population more recently. Populations of hort-distance migrants and permanent residents have been stable throughout this period. Holmes, R.T. and Likens, G.E. 2016

Patterns

The streams at Hubbard Brook are closely interconnected with the forests around them. Ecological theory led us to expect that in the period that we have been measuring the stream chemistry (1963-present), stream nitrate concentrations should have increased because of the continuing deposition of air pollutant nitrogen on the ecosystem, and because the forests have matured and are no longer accumulating nitrogen. In contrast to those expectations, stream nitrate concentrations have declined in the last several decades, leading us to delve deeper into the nitrogen cycle of the forest to explain this surprising finding. Clare Nemes

climate change

View of the greening-up canopy of the Bartlett Experimental Forest, a sister site to Hubbard Brook, from the top of a tower where carbon dioxide exchange in measured by the eddy covariance technique. The instrument in the foreground is a sonic anemometer. These measurements of the exchange of carbon dioxide between the forest and the atmosphere provide a direct measurement of forest productivity. Year-to-year variation in how much carbon dioxide the forest removes from the atmosphere is strongly related to the timing of the start and end of the growing season, with early spring leaf-out and delayed autumn senescence both tending to increase carbon uptake. Andrew Richardson Andrew Richardson