(RCN) Terrestrial Ecosystem Response to Atmospheric and Climatic Change

Future changes in the global carbon balance and associated feedbacks to climate will depend on ecosystem responses to multiple, interacting drivers of global change, such as elevated CO2, temperature, N deposition and changes in the amount and timing of precipitation. Efforts to predict these interactions with modeling approaches have been limited by a lack of relevant experimental data, as well as the absence of mechanisms for rapid communication between modelers and experimentalists. This grant will establish a network of global change scientists in an initiative on Terrestrial Ecosystem Responses to Atmospheric and Climatic Change (TERACC), with the aim to (1) integrate and synthesize existing whole-ecosystem research on ecosystem responses to individual global change drivers, (2) foster new research on whole-ecosystem responses to the combined effects of elevated atmospheric CO2, warming, and other aspects of global change, and (3) promote better communication and integration between experimentalists and modelers. TERACC activities will focus primarily on a series of directed, interactive workshops, but will also include database management and educational activities

A Symposium on \u27Controls on Soil Resoration: Implications for Climate Change\u27; October 27-28, 1997; Anaheim, CA

The potential disruption of global C cycles by human activity in both developed and developing counties is one of the key environmental issues facing human populations as we move into the 21st century. Deforestation of tropical rainforests, changes in land-use, and continued burning of fossil fuels have resulted in an unprecedented increase in atmospheric CO2 concentrations over the last half century. This has raised concerns about potential global warming and climate change, and consequences for further disruptions of the global C cycle. Soil respiration, which represents the combined respiration of roots and soil micro- and macro- biota, represents one of the major pathways of flux in the global C cycle. Thus, a slight increase in soil respiration could significantly exacerbate atmospheric CO2 increases with consequent positive feedback to global climate change, whereas a decrease could offset further anthropogenic CO2 emissions. As such, it is imperative that a better understanding of the factors that control soil respiration is gained and that include consideration of soil carbon storage and flux in discussions of emissions trading and greenhouse gas mitigation efforts is included. In order to define the current state-or-knowledge on soil respiration, provide insight on critical directions for future research, and enhance scientific input to environmental decision-making, this project will assist in the implementation of a Symposium entitled: Controls on Soil Respiration: Implications for Climate Change which will be held at the annual meetings of the Soil Science Society of America in Anaheim, CA, October 27-28, 1997

Workshop: A Cross-Biome Synthesis of Ecosystem Response to Global Warming; October 1998 in Santa Barbara, CA

Greenhouse gas emissions are expected to increase mean global temperature by 3-5 C in the next 50-100 years. The consequences of this warming for primary ecosystem processes are not yet understood, and have become tile focus of an emergent field of ecological research. This project will bring together a multi-disciplinary, international group of scientists representing 22 soil/air warming sites from seven countries to synthesize the current knowledge on the effects of elevated temperature on terrestrial ecosystems. In addition, the participants will use this forum to discuss and launch a new GCTE Ecosystem Warming Consortium, which will have far reaching effects in supporting and promoting future information exchange, technology transfer, and synthesis efforts in ecosystem warming research

LTREB: Forest Ecosystem Response to Changes in Atmospheric Chemistry and Climate at the Bear Brook Watershed in Maine (BBWM)

The Bear Brook Watershed in Maine (BBWM) is a long-term paired, forested watershed research site with each watershed drained by a first order stream through a v-notch weir. One watershed (West Bear) has been treated bimonthly for 12 years with N and S by aerial helicopter applications, with the second watershed (East Bear) serving as the reference watershed. The objectives of this LTREB proposal are to: 1. Study the response of the calibrated East Bear Watershed to long-term patterns of ambient S, N, and base cation deposition. This will be accomplished by maintaining high quality deposition and stream export data from the reference watershed in support of research on ecosystem processes and change over time funded by this project and others. 2. Study the temporal progression of N saturation at the West Bear Watershed. This will be accomplished by continuing the decadal-scale whole ecosystem N & S addition experiment ongoing at the West Bear Watershed. 3. Determine if a definable relationship exists between short and longer-term climate and the biogeochemical and hydrologic processes currently under study at both watersheds. This will be accomplished by establishing an air and soil temperature measurement program across major ecosystem compartments at BBWM. Studies will focus on the relationships between temperature, N dynamics (mineralization, nitrification), and surface water N export in both the reference and treated watersheds, and we will evaluate the efficacy of using heat units to predict ecosystem behavior with respect to these processes. 4. Provide support to strengthen the data management efforts at the BBWM, thereby making this long-term record more accessible to the scientific community with an interpretive interface to be used by educators and policy makers through an expansive web presence. A major emphasis of this LTREB proposal is the development of a layered web presence on the BBWM project that provides access to data and highlights for policy makers, educators and researchers. 5. Provide support for graduate student training and undergraduate student experiences in research. Findings from this research have proven to be turnkey to date in regional and national debates on the effects of acid deposition and the risk of N saturation to forests and surface waters of New England. The compelling justification for supporting the long-term program of research at BBWM is that changes in response to changing ambient deposition of N and S (East Bear), long-term chemical manipulations (West Bear), and seasonal and inter-annual climate variation after 11+ years are showing mechanisms of response that were not discernable within the first 2-3 years of the study. These long-term mechanisms of response are frequently overlooked when research is conducted on short-term funding cycles. The long-term and unique responses being investigated at BBWM will be critical for adequately assessing policy and management options regarding air pollution and climate change in the 21st century

LTREB: Biogeochemical Mechanisms of Response in the Third Decade of Whole-Ecosystem Experimental Manipulations at the Bear Brook Watershed in Maine (BBWM)

This grant will support the Bear Brook Watershed in Maine (BBWM) where research has been conducted for approximately 20 years on the effects of atmospheric sulfur and nitrogen deposition on forests. The research is conducted on two watersheds, each drained by a first order stream. One is treated bimonthly by helicopter to simulate atmospheric deposition of sulfur and nitrogen. Over the past 20 years, this research has identified and verified key factors governing forest response to air pollution, and also revealed major gaps in our understanding that are critical to determining the success of current and potential future regulations under the Clean Air Act and its amendments of 1990. Recent research is also studying how climate interacts with other air pollutants to determine water quality and forest health. This grant will support the project into the third decade where new ecological response mechanisms are emerging that can only be investigated by long-term, multi-decadal research.The broader impacts of this project include the training of undergraduate and graduate students who will be the scientific leaders of tomorrow. This research provides direct evidence of whole-ecosystem responses to chemical treatments that simulate air pollutants providing results not possible from controlled laboratory studies. The issue of acid deposition remains a concern for forest ecosystem health and water quality. There are also direct interactions between climate and acid deposition that few field research sites in the world are prepared to study. This research directly addresses those information needs for today and the future

Does Elevated Nitrogen and Sulfur Deposition Lead to Net Base Cation Losses in Northern New England Forest Soils?

The aims of this research are to continue treatment and monitoring of a paired watershed experiment at Bear Brook in northern Maine, with an emphasis on changes in soil base cations, particularly calcium. Base cation depletion is well-recognised as a potential problem in soils that have been subjected to acidic N deposition but few data exist from well-controlled, long-term experiments. The Bear Brook watershed has been periodically treated with ammonium sulfate since the fall of 1989 and is believed to be approaching N saturation. Since 1993 the relationship between base cations and strong acid anions has changed, such that labile Ca and Mg may be depleted in the soils as Al losses increase. Continued monitoring will allow tests of a series of hypotheses about controls and mechanisms of cation retention and leaching in temperate forest soils

TB196: Temperature, Soil Moisture, and Streamflow at the Bear Brook Watershed in Maine (BBWM)

The Bear Brook Watershed in Maine is a whole-ecosystem chemical manipulation initiated in 1987 to study the effects of acid deposition on forests and surface waters. The focus of this research was to understand the biogeochemical response of watersheds with emphasis on chemistry and hydrology. In 2001 a program was initiated to provide more detailed measurements of temperature and moisture to examine critical linkages amongst chemical, biological, and physical processes that ultimately work together to define ecosystem function. The purpose of this publication is to provide data from the initial phase of soil temperature, air temperature, and soil moisture measurements at the site. In addition, the authors have incorporated aspects of relevant precipitation and streamflow characteristics available for the full project period.https://digitalcommons.library.umaine.edu/aes_techbulletin/1001/thumbnail.jp

TB178: Methods for Evaluating Carbon Fractions in Forest Soils: A Review

This publication was developed as part of an effort to evaluate the existing methodologies for determining carbon fractions in soils that might be applied to the question of forest soil C sequestration. A great deal of research has been done on this topic although often focused on agronomic soils. Forest land managers will be increasingly interested in identifying methods to monitor and to evaluate the effects of forest practices on soil C reserves. As well researchers are interested in this and the logical linkages to N cycling. Ultimately practical methods that can be widely utilized will be needed; these may come from current methods or be developed through research. This review offers a framework for this area of investigation.https://digitalcommons.library.umaine.edu/aes_techbulletin/1030/thumbnail.jp

Long-Term Integrated Studies Show Complex and Surprising Effects of Climate Change in the Northern Hardwood Forest

Evaluations of the local effects of global change are often confounded by the interactions of natural and anthropogenic factors that overshadow the effects of climate changes on ecosystems. Long-term watershed and natural elevation gradient studies at the Hubbard Brook Experimental Forest and in the surrounding region show surprising results demonstrating the effects of climate change on hydrologic variables (e.g., evapotranspiration, streamflow, soil moisture); the importance of changes in phenology on water, carbon, and nitrogen fluxes during critical seasonal transition periods; winter climate change effects on plant and animal community composition and ecosystem services; and the effects of anthropogenic disturbances and land-use history on plant community composition. These studies highlight the value of long-term integrated research for assessments of the subtle effects of changing climate on complex ecosystems

A new generation of sensors and monitoring tools to support climate-smart forestry practices

Climate-smart forestry (CSF) is an emerging branch of sustainable adaptive forest management aimed at enhancing the potential of forests to adapt to and mitigate climate change. It relies on much higher data requirements than traditional forestry. These data requirements can be met by new devices that support continuous, in situ monitoring of forest conditions in real time. We propose a comprehensive network of sensors, i.e., a wireless sensor network (WSN), that can be part of a worldwide network of interconnected uniquely addressable objects, an Internet of Things (IoT), which can make data available in near real time to multiple stakeholders, including scientists, foresters, and forest managers, and may partially motivate citizens to participate in big data collection. The use of in situ sources of monitoring data as ground-truthed training data for remotely sensed data can boost forest monitoring by increasing the spatial and temporal scales of the monitoring, leading to a better understanding of forest processes and potential threats. Here, some of the key developments and applications of these sensors are outlined, together with guidelines for data management. Examples are given of their deployment to detect early warning signals (EWS) of ecosystem regime shifts in terms of forest productivity, health, and biodiversity. Analysis of the strategic use of these tools highlights the opportunities for engaging citizens and forest managers in this new generation of forest monitoring.Peer reviewe