Open Access. Powered by Scholars. Published by Universities.®

Environmental Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Environmental Sciences

Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas Aug 2012

Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas

School of Natural Resources: Faculty Publications

Light, nutrient availability, and flow are strong factors controlling the elemental composition and biomass of epilithon in temperate stream ecosystems. However, comparatively little is known about these relationships in tropical streams. We investigated how gradients of light and nutrient availability, seasonality, and habitat influenced epilithon biomass, chlorophyll a, and nutrient ratios in montane streams of Trinidad, West Indies. We sampled 4 focal tributaries of a single river, 2 of which had canopies experimentally thinned, every other month over a 2-y period to observe temporal dynamics and light effects on epilithon. We also sampled 18 sites across Trinidad’s Northern Range Mountains …


Reconstructing Disturbance History Using Satellite-Based Assessment Of The Distribution Of Land Cover In The Russian Far East, T.V. Loboda, Z. Zhang, K.J. O'Neal, G. Sun, I.A. Csiszar, H.H. Shugart, N.J. Sherman Jan 2012

Reconstructing Disturbance History Using Satellite-Based Assessment Of The Distribution Of Land Cover In The Russian Far East, T.V. Loboda, Z. Zhang, K.J. O'Neal, G. Sun, I.A. Csiszar, H.H. Shugart, N.J. Sherman

United States Department of Commerce: Staff Publications

Russian boreal forests are the largest forested zone on Earth and a tremendous pool of organic carbon. Current limited records on forest structure, composition, successional stage and disturbances contribute to large uncertainties in estimates of carbon stocks and fluxes in this zone. Our ability to monitor ongoing changes in forest cover has improved with the influx of remotely sensed data products since 2000 from multiple satellite platforms. Here we present a method aimed at reconstructing disturbance history from a known distribution of land cover. We developed and tested the method over a biologically and topographically diverse region of the Russian …


Spatial Complexity In Fragmenting Amazonian Rainforests: Do Feedbacks From Edge Effects Push Forests Towards An Ecological Threshold?, Graeme S. Cumming, Jane Southworth, Xanic J. Rondon, Matthew Marsik Jan 2012

Spatial Complexity In Fragmenting Amazonian Rainforests: Do Feedbacks From Edge Effects Push Forests Towards An Ecological Threshold?, Graeme S. Cumming, Jane Southworth, Xanic J. Rondon, Matthew Marsik

United States Department of Commerce: Staff Publications

Deforestation and resulting landscape fragmentation are important concerns in many tropical areas. Deforestation is a complex process with many potential feedback loops, many of which are ignored in models that attempt to interpolate forest loss based on past deforestation rates. In addition, most ecological studies of the impacts of deforestation have focused on landscapes that are already fragmented. These studies ignore the fact that edge effects, such as anthropogenic fire, reach their maximum well before habitat connectivity is lost and may create positive feedbacks that result in further fragmentation. We developed a simple model to explore the potential influence of …


Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes Jan 2012

Hurricane Disturbance And Recovery Of Energy Balance, Co2 Fluxes And Canopy Structure In A Mangrove Forest Of The Florida Everglades, Jordan G. Barr, Vic Engel, Thomas J. Smith, José D. Fuentes

United States Geological Survey: Staff Publications

Eddy covariance (EC) estimates of carbon dioxide (CO2) fluxes and energy balance are examined to investigate the functional responses of a mature mangrove forest to a disturbance generated by Hurricane Wilma on October 24, 2005 in the Florida Everglades. At the EC site, high winds from the hurricane caused nearly 100% defoliation in the upper canopy and widespread tree mortality. Soil temperatures down to −50 cm increased, and air temperature lapse rates within the forest canopy switched from statically stable to statically unstable conditions following the disturbance. Unstable conditions allowed more efficient transport of water vapor and CO2 from …