Nitrate (NO₃^-) and dissolved organic carbon (DOC) concentration in stream water after clear-cutting of trees and subsequent strip-cutting of understory vegetation, dwarf bamboo (Sasa spp.) were investigated to understand the effect of these disturbances on biogeochemical processes in forested watershed in Teshio Experimental Forest, one of the JaLTER site, in northern Japan. Trees of 8 ha watershed except riparian zone were clear-cut in January?March of 2003.

Dispersal ability can affect the dynamics and composition of intertidal communities. Sandy beach ecosystems, where several key taxa have limited dispersal, are increasingly impacted by growing coastal development, and human use, while facing additional habitat loss and fragmentation from sea level rise. Implications of low dispersal rates for populations of key beach taxa, such as talitrid amphipods, include susceptibility to local extinctions and potentially lengthy recolonization times relative to lifespans/generation times.

Urban ecosystems present ecologists with the unique opportunity to study ecological communities in the context of drastic structural and environmental change unprecedented in pristine environments. Metacommunity theory organizes a suite of predictions of how species assemble locally from the regional species pool. Understanding assemblage structure in urban ecosystems requires a revised perspective embracing human behavior and decision-making.

Hurricanes are major perturbations in Caribbean forests. They result in canopy removal and deposition of pulses of litter to the forest floor, which can alter biotic and biogeochemical processes. In Puerto Rico, Hurricane Georges (1998) struck the Luquillo Mountains and caused 0.55 – 0.93 times the annual litterfall. Forest floor standing stocks were then 1.2 - 2.5 times greater than pre-Georges values. Litter standing stocks returned to normal within a year; but it was not clear if canopy opening and/or hurricane litter deposition had stimulated decomposition.

Disturbance from fire can affect the abundance and distribution of shrubs and grasses in arid ecosystems. Specifically, fire may increase grass and forb production while hindering shrub encroachment. Therefore, prescribed fires are a common management tool for maintaining grassland habitats in the southwest. However, Bouteloua eriopoda (black grama), a dominant species in Chihuahuan Desert grassland, is highly susceptible to fire resulting in death followed by slow recovery rates.

Post-fire nutrient enrichment is known to affect benthic macroinvertebrate assemblages and stream food webs in forested regions, but little is known about the impact of tundra fires. The 2007 Anaktuvuk River fire (North Slope, Alaska), the largest recorded tundra fire (≈1,000 km²), provided an opportunity to study the first-year effects of a tundra fire on stream communities. We predicted that a tundra fire would increase inorganic nutrient inputs to streams, thereby increasing primary production and in turn, increasing abundance and biomass of benthic macroinvertebrates.

Microorganisms have confounded biogeographers because of their high dispersal capability, small size, and vast diversity and abundance. Here we use pyrosequencing, bioinformatics tools, and geospatial modeling to reveal that the genetic relatedness of soil bacteria varies in a predictable pattern across a landscape. Microbial communities showed strong spatial autocorrelation to a distance of 240 meters and this pattern was driven by changes in the genetic relatedness and abundance of specific clades across the landscape.

Global change may alter the frequency and seasonality of temperate lake mixing, with unknown ecosystem consequences. Mixing disrupts vertical chemical and physical gradients, such as dissolved oxygen (DO) and temperature, which then influence biological dynamics. We conducted a mixing manipulation to observe whole lake response to episodic mixing, with a focus on the physical and chemical drivers of bacterioplankton communities. We mixed a temperate, dimictic bog lake during summer stratification.

Optical methods such as turbidimetry, UV-visible spectroscopy and fluorescence spectroscopy are alternative methods for water quality characterization. They are reagent free and can be used in-situ or off-line. These methods have been used to assess and compare the quality of various streams in the Moselle watershed. Moselle (550 km) is a major tributary of the Rhine river and is flowing through three Western European countries (France, Luxembourg and Germany).

Carbon isotopes are valuable tools for determining the overall ambient conditions under which trees incorporate seasonal growth, and can act as indicators of periods of environmental stress, including salt water intrusion and droughts. When coupled with traditional dendrochronological analyses, carbon isotopes can potentially relay a high-resolution history of localized hydrologic conditions, and highlight intervals of increased tropical cyclone activity and precipitation frequency as well as long-term trends in freshwater availability.