A5011278919- Plant Water Relations and Carbon Dynamics
- Atmospheric and Environmental Gas Dynamics
- Climate change and permafrost
- Soil Carbon and Nitrogen Dynamics
- Peatlands and Wetlands Ecology
- Cryospheric studies and observations
- Environmental and biological studies
- Forest ecology and management
- Hydrology and Watershed Management Studies
- Plant responses to elevated CO2
- Rangeland and Wildlife Management
- Remote Sensing in Agriculture
- Fire effects on ecosystems
- Geology and Paleoclimatology Research
- Ecology and Vegetation Dynamics Studies
- Soil and Unsaturated Flow
- Atmospheric chemistry and aerosols
- Soil Management and Crop Yield
- Soil erosion and sediment transport
- Soil and Water Nutrient Dynamics
- Tree-ring climate responses
- Plant responses to water stress
- Coastal wetland ecosystem dynamics
- Leaf Properties and Growth Measurement
- Solar Radiation and Photovoltaics
California State University, San Marcos
2016-2025
Universidade Federal de Mato Grosso
2004-2023
California State University System
2008-2023
Finnish Meteorological Institute
2021
Chinese University of Hong Kong
2021
Northern Arizona University
2021
University of Helsinki
2021
University of Alaska Fairbanks
2021
Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde
2018
Universidade de Cuiabá
2018
Summary Although trees have responded to global warming in the past – temperatures higher than they are now rate of change predicted 21st century is likely be unprecedented. Greenhouse gas emissions could cause a 3–6°C increase mean land surface temperature at high and temperate latitudes. Despite this, few experiments isolated effects for this scenario on forests. This review focuses tree forest responses boreal latitudes, ranging from cellular ecosystem level. Adaptation varying revolves...
We investigated the seasonal patterns of water vapor and sensible heat flux along a tropical biome gradient from forest to savanna. analyzed data network towers in Brazil that were operated within Large‐Scale Biosphere‐Atmosphere Experiment Amazonia (LBA). These tower sites included humid semideciduous forest, transitional floodplain (with physiognomies cerrado), cerrado sensu stricto. The mean annual at all ranged 20 38 Wm −2 , was generally reduced wet season increased late dry season,...
In this study, we presented the most commonly employed net photosynthetic light-response curves (P N/I curves) fitted by Solver function of Microsoft Excel. Excel is attractive not only due to its wide availability as a part Office suite but also increased level familiarity undergraduate students with tool opposed other statistical packages. explored use didactic which was built upon previously published paper presenting an for calculation photosynthetic/chloroplastic CO2-response curve....
Abstract While wetlands are the largest natural source of methane (CH 4 ) to atmosphere, they represent a large uncertainty in global CH budget due complex biogeochemical controls on dynamics. Here we present, our knowledge, first multi‐site synthesis how predictors fluxes (FCH4) freshwater vary across wetland types at diel, multiday (synoptic), and seasonal time scales. We used several statistical approaches (correlation analysis, generalized additive modeling, mutual information, random...
Recent evidence indicates that significant amounts of C may be lost as CO 2 to the atmosphere from tundra ecosystems during fall, winter and spring months. Because high latitude are particularly vulnerable climate change, contain large soil stocks, annual budget is particular interest. Significant loss were observed in arctic North Slope Alaska 1993–1994 cold season. Moist tussock approximately 0.3 gC m −2 d −1 between mid‐October late May while coastal wet sedge on average 0.08 . Efflux...
A significant difference in net ecosystem carbon balance of wet sedge ecosystems the Barrow, Alaska region was observed between CO 2 flux measurements obtained during International Biological Program 1971 and made 1991‐1992 growing seasons. Currently, high‐center polygons are sources to atmosphere ≈14 gC·m ‐ ·yr 1 , while low‐center losing ≈3.6 ice wedge habitats accumulating 4.0 . On average, moist meadow characteristic IBP‐II site currently ≈1.3 compared reported accumulation ≈25...
[1] Tropical savanna (locally known as cerrado) composes 24% of Brazil and is characterized by high climatic variation; however, patterns energy exchange are poorly understood, especially for mixed grasslands campo sujo). We used eddy covariance to measure latent (Le) sensible (H) heat flux a grassland linked meteorological remote sensing data determine the controls on these fluxes. hypothesized that (1) seasonal variations in H Le would be large due precipitation; (2) ecosystem phenology,...
The Large‐scale Biosphere–Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage, nutrient dynamics, trace gas fluxes, the prospect for sustainable land use Amazon region. Early results from ecological within emphasize variability vast region profound effects that land‐use land‐cover changes are having landscape....
Abstract In situ manipulations were conducted in a naturally drained lake on the arctic coastal plain near Prudhoe Bay, Alaska (70 °21.98′ N, 148 °33.72′ W) to assess potential short‐term effects of decreased water table and elevated temperature net ecosystem CO 2 flux. The experiments over 2‐year period, during that time, depth plots was maintained average 7 cm lower than ambient table, surface temperatures exposed increased 0.5 °C. Water drainage, lesser extent temperature, resulted...
The seasonal pattern of evapotranspiration (expressed as latent heat flux Q e ) for a 28‐ to 30‐m‐tall tropical transitional (ecotonal) forest was quantified over an annual cycle using eddy covariance measurement and micrometeorological estimation techniques. study conducted near the city Sinop, in northern Mato Grosso, Brazil, which is located within ecotone rain savanna (cerrado). Although majority net radiation ( *) consumed by (50–90%), variations were large positively correlated with...
1 Eddy covariance was used to measure landscape-scale fluxes of C02, H20 vapour and energy in moist-wet sedge tundra ecosystems coastal arctic Alaska. 2 Net radiation (Rn) partitioned equally into sensible (H) latent heat (Le), although a larger proportion Rn Le during after the early season snow-melt period, while proportionally more H as progressed. Ground flux (G) comprised an average 15% throughout growing season. 3 Interannual variation evapotranspiration (ET) negligible despite 30%...
Deforestation and climate change have the capacity to alter rainfall regimes, water availability, surface‐atmosphere flux of energy tropical forests, especially in ecotonal, semi‐deciduous forests southern Amazon Basin, which experienced rapid regional warming deforestation over last three decades. To reduce uncertainty regarding current future flux, micrometeorological measurements latent ( Q e ) sensible heat h canopy conductance G c were combined with sap density F d maximum leaf g smax...
Abstract Wetlands are important sources of methane (CH 4 ) and sinks carbon dioxide (CO 2 ). However, little is known about CH CO fluxes dynamics seasonally flooded tropical forests South America in relation to local (C) balances atmospheric exchange. We measured net ecosystem the Pantanal over 2014–2017 using tower‐based eddy covariance along with C measurements soil, biomass water. Our data indicate that potentially large for but strong , particularly during inundation when reducing...
Atmospheric nitrogen (N) deposition is enriching soils with N across biomes. Soil enrichment can increase plant productivity and affect microbial activity, thereby increasing soil organic carbon (SOC), but such responses vary Drylands cover ~45% of Earth's land area store ~33% global SOC contained in the top 1 m soil. Nitrogen fertilization could, therefore, disproportionately impact (C) cycling, yet whether dryland storage increases remains unclear. To understand how may change storage, we...
Eddy covariance was used to measure the net CO2 exchange and energy balance of a moist-tussock tundra ecosystem at Happy Valley, Alaska (69°08.54′ N, 148°50.47′ W), during 1994–1995 growing seasons (June–August). The system operated for 75–95% time, closure within 5%, indicating good performance. Daily rates evapotranspiration (ET) were on average 1.5 mm/d, while seasonal ET ranged between 100 150 mm. strongly correlated with daily fluctuations in radiation. However, "omega factor" (an index...