Carbon dioxide sequestration by forests: The importance of cation and phosphorous limitation and its relationship to landscape evolution

This interdisciplinary research will investigate how landscape processes may influence chemical weathering, which may have important impacts on the input of nutrients to forest ecosystems. This project will develop coupled numerical models of landscape evolution and chemical weathering, and test and calibrate these models in the ecosystems in Hawaii and tectonically active areas along the Pacific Rim.  In so doing, researchers intend to build predictive models that will be able to identify forests that have the greatest long-term ability to sequester CO2. One of the most significant carbon dioxide reservoirs on Earth is its forests. As anthropogenic inputs increase atmospheric CO2 levels, there is potential that an increase in total plant biomass – the ‘greening’ of the earth’s forests – might serve as a long-term sink for human-produced carbon dioxide. Such a sink will only be sustainable if the other requisite nutrients for plant growth are readily available and do not limit photosynthesis. In terrestrial ecosystems, the nutrient flux (Mg, Ca, K, and PO4 3- , Ca, K, and Mg) into the system is controlled to a large extent by the chemical weathering of the primary minerals that make up underlying bedrock. In the temperate zone, these nutrient fluxes have been severely disturbed by anthropogenic activity, such as acid rain, resulting in forest ecosystems that may be cation-limited and thus not have the ability to serve as long-term sinks of anthropogenic CO2 (Federer et al., 1989; Bailey et al., 1996; Fitcher et al., 1998; Lawrence et al., 1999; Yanai et al., 1999; DeWalle et al., 1999; Huntington et al., 1999). In many tropical forests, these nutrient fluxes are thought to be minimal, because the soils often appear highly weathered and are so deep as to preclude biotic access to unweathered bedrock. Most of the work in temperate forests has been done in the northeastern United States and western Europe, while much of the tropical work on nutrient limitation has been done in Central and South America, and Hawai’i. Many of these studies may paint an unrepresentative picture of nutrient input rates, because they are on the low end of the spectrum of tectonic activity and uplift. Preliminary investigations have demonstrated that the dominant control of chemical weathering rates is the exposure of fresh rock to the weathering zone, through such processes as rock uplift in tectonically active areas and/or hill slope stability in mountainous terrain (Waldbauer and Chamberlain, in press). These models show that chemical weathering rates may be several orders of magnitude higher in tectonically active areas such as the Pacific Rim than in relatively stable areas such as the east coast of North America or Amazon (both areas that have received considerable attention with regard to their ability to store CO2 in forests). This EVP will couple numerical models of landscape evolution (Hilley) with numerical models of chemical weathering (Chamberlain), and test and refine these models with data from terrestrial ecosystems (Porder and Vitousek). The overall goal of this research will be to build predictive models that will be able to identify forests that have the greatest long-term ability to sequester CO2. We will systematically and quantitatively determine the link between chemical weathering and landscape evolution and test these models through a series of field investigations. By quantifying rates of nutrient inputs to forests, and by understanding landscape evolution and its relationship to chemical weathering, it should be possible to identify forests that will have the ability to serve as sinks for CO2. If successful, this will aid policymakers and NGOs in select the most important CO2 sinks for management and preservation.

Forest conversion and the changing epidemiological environment in southeast Asia

Can Better Management Raise Growth and Reduce Pollution?

Geography of Food Contamination by Coal Emissions in N.W. China

Compromised Groundwater Quality Resulting from Large-Scale Damming Projects

Is Corporate Environmentalism Profitable? Experimental Investigations of the Effects of Environmental Corporate Social Responsibility on Consumption, Employment and Political Activity

Mitigating future arsenic catastrophes in Asia: An integrative study of processes controlling arsenic release induced by land use

Arsenic is having a devastating impact on human health in Asia. In Bangladesh and West Bengal alone, an estimated 57 million people are exposed to drinking water with arsenic concentrations exceeding the World Health Organization's recommended limit of 10 µg/L. It is our hypothesis that different land uses will limit arsenic exposure to tens of millions more individuals within Southeast and Sub-continental Asia. We therefore propose an interdisciplinary study focusing on how land use alters the solid-water partitioning of arsenic in Cambodia and Vietnam. Our study blends an integrative scientific investigation of chemical, biological, and hydrologic factors controlling arsenic partitioning with an evaluation of the relationship between agricultural policies and farming practices on these processes. This research is a significant departure from existing efforts, in terms of scope and geography, with the goal of understanding the relative impact land use will have on biogeochemical mechanisms responsible for arsenic liberation.

Consequences of increased global meat consumption on the global environment -- trade in virtual water, energy & nutrients

Meat production is projected to double by 2020 due to increased per capita global consumption of meat and population growth. Most of this increase in production will come through industrialized animal production systems. These trends will have major consequences on the global environment. Vast transfers of "virtual" energy, water and nutrients will occur among nations that will have large impacts on local and distant environments. A full accounting of these trends and projections will give us the capacity to propose policies to ameliorate the negative aspects of these developments and position us to address the multiple consequences of industrialized animal production systems.

Indoor air pollution and health in developing countries: An intervention study in Bangladesh

This research represents a new interdisciplinary collaboration at Stanford to investigate the behavioral underpinnings of indoor air pollution in the developing world and to estimate its impact on human health. Researchers will work with a number of public agencies, private companies and NGOs.

An interdisciplinary assessment of an agricultural-urban water market in Southern India: physical impacts, welfare consequences, and policy implications

This research project analyzes the rural-urban groundwater market in Chennai (formerly Madras, in South India), as a case study of water resources sustainability in a developing nation. The research develops a combined hydrogeological and economic framework to consider the biophysical and welfare impacts of future water demands in the region. In addition, this work examines the potential of public policies to alter the time-profiles of water supplies and demands and thereby enhance social welfare.