Global hydroclimatic conditions have been significantly altered, over the past century, by anthropogenic influences that arise from warming global climate and also from local/regional anthropogenic disturbances. There has been never been an effort that has systematically analyzed how the spatio-temporal variability of land-surface fluxes vary in natural and human-altered watersheds globally....

Advancing our mechanistic understanding of ecosystem responses to climate change is critical to improve ecological theories, develop predictive models to simulate ecosystem processes, and inform sound policies to manage ecosystems and human activities. Manipulation of temperature in the field, or the “ecosystem warming experiment,” has proved to be a powerful tool to understand ecosystem...

Regional- to continental-scale paleoclimate syntheses of temperature and hydroclimate in North America are essential for understanding long-term spatiotemporal variability in climate, and for properly assessing risk on decadal and longer timescales. However, existing syntheses rely almost exclusively on tree-ring records, which are known to underestimate low-frequency variability and rarely...

Groundwater contaminated with naturally occurring arsenic is a widespread problem affecting many alluvial and deltaic aquifer systems throughout the world. The human health toll from consuming groundwater with high levels of arsenic is staggering in its proportions. Furthermore, the use of arsenic contaminated groundwater for irrigation is observed to result in diminished crop yields and thus...

The timing of breeding is constrained in Arctic ecosystems and small temporal differences in when individuals breed can have large effects on fitness. Arctic ecosystems are generally warming more rapidly than other ecosystems which, for migratory species, can cause an imbalance, or mismatch, between when they have evolved to breed versus when it is optimal to breed environmentally. Geese are...

Drylands are integral to the Earth system and the present and future of human society. Drylands encompass more than 40% of the terrestrial landmass and support 34% of the world’s human population. Biocrusts are the “living skin” of Earth’s drylands, sometimes dominating the ground cover and figuring prominently in ecosystem structure and function. Biocrusts are a biological aggregate of...

Dam decommissioning is rapidly emerging as an important river restoration strategy in the U.S., with several major removals recently completed or in progress. But few studies have evaluated the far-reaching consequences of these significant environmental perturbations, especially those resulting from removals of large (>10-15 m tall) structures during the last decade. In particular,...

Fibrous erionite, a zeolite mineral, has been designated as a human carcinogen by the World Health Organization and is believed to be the cause of extraordinarily high rates of malignant mesothelioma and other asbestos - related diseases in several villages in Central Turkey. A recent study by the University of Hawaii in collaboration with the U. S. Environmental Protection Agency in Dunn...

The impacts of nitrogen (N) deposition on plant diversity loss have been well documented across N deposition gradients in Europe, but much less so in the U.S. Published N fertilizer studies suggest losses will occur in the US, but many of these were done at levels of N input that were higher than modeled and measured N deposition, and higher than presumed N critical loads. The recent...

Nitrogen deposition is altering forest dynamics, terrestrial carbon storage, and biodiversity. However, our ability to forecast how different tree species will respond to N deposition, especially key response thresholds, is limited by a lack of synthesis across spatial scales and research approaches. To develop our best understanding of N deposition impact on tree growth and survival, we will...

Global climate change is putting unprecedented pressure on global croplands and their water use, vital for ensuring future food security for the world's rapidly expanding human population. The end of the green green revolution (productivity per unit of land) era has meant declining global per capita agricultural production requiring immediate policy responses to safeguard food security amidst...

Shale gas is a key source of onshore domestic energy for the United States and production of this resource is increasing rapidly. Development and extraction of shale gas requires hydraulic fracturing, which entails horizontal drilling, perforation of steel casing and cement grout using explosive charges, and expansion of fractures using fluids under high pressure. Concern over potential...

Groundwater storage depletion is a critical issue for many of the major aquifers in the U.S., particularly during intense droughts. The GRACE (Gravity Recovery and Climate Experiment) satellites launched in 2002, with sensors designed to measure changes in the Earth’s gravitational field at large spatial scales (≥ ~200,000 km2). These changes are primarily driven by changes in water storage on...

Despite the best monitoring networks, the highest rate of earthquakes and the longest continuous recorded history in the world, this year’s M=9.0 Tohoku, Japan, earthquake was completely unforeseen. The Japanese had expected no larger than a M=8 quake in the Japan trench, 1/30 th the size of the Tohoku temblor. This year also saw the devastating M=6.3 Christchurch, New Zealand earthquake and...

Coral reefs are massive, wave resistant structures found throughout the tropics, where they have long attracted attention for their beauty, ecological importance, and rich biological diversity. However, in recent years attention to these systems has focused on their downturn in health and the potential that they effectively could disappear within a century. Yet while many coral reefs have...

Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may disproportionally...

While it is widely recognized that microorganisms are intimately linked with every biogeochemical cycle in all ecosystems, it is not clear how and when microbial dynamics constrain ecosystem processes. As a result, it is know clear how to apply the value of increasingly detailed characterization of microbial properties to our understanding of ecosystem ecology. Several recent papers have...

Ecosystems are changing worldwide and critical decisions that affect ecosystem health and sustainability are being made every day. As ecologists, we have a responsibility to ensure that these decisions are made with access to the best available science. However, to bring this idea into practice, ecology needs to make a substantial leap forward towards becoming a more predictive science....

Biological nitrogen fixation (BNF) is a critical biogeochemical process that converts inert atmospheric N2 gas into biologically usable forms of the essential nutrient nitrogen. A variety of free-living and symbiotic organisms carry out BNF, and in most regions worldwide, BNF is the largest source of nitrogen that fuels terrestrial ecosystems. As a result, BNF has far reaching effects on...

A vast number of the world’s volcanoes are unmonitored by ground-based sensors, yet constitute an important hazard to nearby residents and infrastructure, as well as air travel and the global economy. Satellite data provide a cost-effective means of tracking activity at such volcanoes. Unfortunately, satellite acquisitions are not optimized for application to volcano hazards, in part because...

Groundwater withdrawals in the western US are a critical component of the water resources strategy for the region. Climate change already may be substantially altering recharge into groundwater systems; however, the quantity and direction (increase or decrease) of changes are relatively unknown as most climate change assessments have focused on surface water systems. We propose to conduct a...

Rivers are the veins of the landscape, providing environmental benefits that are disproportionately high relative to their aerial extent; shedding flood waters, hosting aquatic ecosystems, transporting solutes and energy-rich materials, and storing and transforming pollutants into less harmful forms. From uplands to the coasts, rivers facilitate key biogeochemical reactions that cumulatively...

The transport of dissolved organic matter (DOM) by rivers is an important component of the global carbon cycle, affects ecosystems and water quality, and reflects biogeochemical and hydrological processes in watersheds. Understanding the fundamental relationships between discharge and DOM concentration and composition reveals important information about watershed flow paths, soil flushing,...

Resilience science provides a conceptual framework and methodology for quantitatively assessing the ability of a system to remain in a particular state. Probable non-linear ecological responses to global change, including climate change, require a clear framework for understanding and managing resilience. However, much of the resilience research to date has been qualitative in nature, and...

There has been increasing attention placed on the need for water availability information at ungauged locations, particularly related to balancing human and ecological needs for water. Critical to assessing water availability is the necessity for daily streamflow time series; however, most of the rivers in the United States are ungauged. This proposal leverages over $1M currently allocated to...

Soils are a vast reservoir of organic carbon (C), rendering the fate of soil C an important control on the global climate system. Widespread changes in soil C storage capacity present a potentially strong feedback to global change. Yet, a comprehensive understanding of how soil C will respond to climate and/or land use disturbance remains illusive, resulting in major uncertainties in global...

Water in the United States is used for myriad activities on a daily basis, such as for food (irrigation, aquaculture, livestock), energy (thermoelectric power or hydropower generation), and public water supply for domestic, commercial or industrial purposes. Yet, we lack an national accounting of how and where water is used on a temporal scale more frequent than every 5 years, and a spatial...

Fresh water is arguably the most valuable resource on the planet, but human activities threaten freshwater ecosystems. For example, use of synthetic chemicals, such as pesticides, road salts, and nutrients, has led to the ubiquitous contamination of aquatic systems, jeopardizing the integrity of ecological communities. Given the importance biodiversity plays in maintaining ecosystem health and...

River ecosystems support a wide diversity of biota, including thousands of fish species, which are variously adapted to the dynamic environments provided by flowing-water habitats. One of the primary ways that human activities diminish the biological capacity of rivers is by altering the natural hydrologic variability of river systems through regulation and diversion of streamflow for other...

Our ability to effectively manage natural resources is founded in an understanding of how our actions and the environment influence populations, communities, and ecosystems. Current practices use monitoring data from the past to determine key ecological relationships and make predictions about the future with the assumption that those relationships will remain constant. However, many natural...

Plants convert carbon dioxide into sugars for food during photosynthesis, and this provides food for all animal life. However, photosynthesis is inhibited when a plant’s enzymes use oxygen instead of carbon dioxide. To avoid this use of oxygen, some plants developed a photosynthetic adaptation – called C4 photosynthesis – to concentrate carbon dioxide around the enzymes. While less than 5% of...