Warming of the global climate is now unequivocal and its impact on Earth' functional units has become more apparent. Here, we show that marine ecosystems are not equally sensitive to climate change and reveal a critical thermal boundary where a small increase in temperature triggers abrupt ecosystem shifts seen across multiple trophic ...

... 08-232.1 Climate-Driven Interannual Variability in Net Ecosystem Exchange in the Northern Great Plains GrasslandsLi Zhang1, Bruc...

Desiccation of the Sahara since the middle Holocene has eradicated all but a few natural archives recording its transition from a "green Sahara" to the present hyperarid desert. Our continuous 6000-year paleoenvironmental reconstruction from northern Chad shows progressive drying of the regional terrestrial ecosystem in response to weakening insolation forcing of the African ...

... their carbon stock. Climate-Driven Interannual Variability in Net Ecosystem Exchange in the Northern Great Plains Grasslands Li Zhang, ... From Flux-Tower MeasurementsClimate-Driven Interannual Variabili...

Climate changes characterized as global warming can lead to irreversible effects on regional and global scales, such as drought, pest attacks, diseases, excessive forest fires, and climate driven extinction of numerous animal and plant species. We assess the issues that the development of forestry in Armenia faces, where the climate change is causing the ...

as methane hydrate in the sea floor and permafrost soils and (2) climate-driven changes in methane emissions from northern high-latitude and tropical wetlands. � The size of the methane hydrate reservoir-latitude hydrates and wetlands resulting from increasing Arctic temperatures. � Catastrophic release of methane

Climate change is known to affect the carbon balance of Arctic tundra ecosystems by influencing plant growth and decomposition. Less predictable climate-driven biotic events, such as disease outbreaks, are now shown to potentially shift these ecosystems from net carbon sinks to sources.

We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern Atlantic. Results show that deep-sea benthic community �collapses� occur with faunal turnover of up to 50% during major climatically driven ...

We investigated high-resolution deep-sea sediment core records of benthic ostracodes during periods of rapid climate and oceanographic change of the last 20,000 years in the Ocean Drilling Program Hole 1055B, western subtropical North Atlantic (32� 47.041'N, 76�17.179'W; 1798 m water depth). Age control was established with radiocarbon and oxygen isotope. Results show that deep-sea benthic ...

... Knapp and Smith 2001), and carbon cycling and net ecosystem exchange are influenced by interannual variability in precipitation (Chou ... L. Tiezen. 2010. Climate-driven interannual variability in net eco...

Net ecosystem exchange of CO2 (NEE) of terrestrial ecosystems varies seasonally and inter-annually partly because of climatic variability. If we are to predict climate-driven variation in NEE, we must understand how climatic anomalies at different temporal scales influence NEE and its components, ...

Phenology is the study of cyclic biological events and its relationship to abiotic factors. Timing of flowering, fruiting and leafing is highly correlated to environmental factors such as temperature, precipitation, irradiance and isolation. Accordingly, any change in these factors may have a direct effect on the initiation, intensity and duration of different phenophases. Tropical phenology has ...

into the atmosphere because of the green house gas accumulation in the atmosphere. Therefore warming will mainly occur, Roskilde, Denmark January 2000 #12;#12;RIS� �R�1167(EN) 2 Abstract Emission of green house gases, partly investigates the potential effects of warming and drought on heath and moorland ecosystems at four European

Consensus exists that U.S. coastal ecosystems are severely degraded due to a variety of human-factors requiring large financial expenditures to restore and manage. Yet, even as controversy surrounds human factors in ecosystem degradation in the Gulf of Mexico, Chesapeake Bay, an...

... will most likely not return to its previous state," said USGS Associate Director for Biology Susan Haseltine. "The ... ...

U.S. Geological Survey (USGS) scientists who study trends in climate change will be presenting the results from new studies at a workshop held in Pacific ... ...

Fifty-five paleolimnological records from lakes in the circumpolar Arctic reveal widespread species changes and ecological reorganizations in algae and invertebrate communities since approximately anno Domini 1850. The remoteness of these sites, coupled with the ecological characteristics of taxa involved, indicate that changes are primarily driven by climate warming through lengthening of the ...

Reconstructions from sedimentary records and climate modelling results show an overall drying in the African Sahara and Sahel during the Holocene. Was this change abrupt or gradual, and amplified or not through vegetation change and feedbacks to the atmosphere is still the subject of debate. For instance, while [deMenocal et al. 2000] show from oceanic sediments off the ...

This report is an attempt to describe what is known about abrupt climate changes and their impacts, based on paleoclimate proxies, historical observations, and modeling. Large, abrupt climate changes have repeatedly affected much or all of the earth, locally reaching as much as 10 Celsius degrees change in 10 years. Available evidence suggests that ...

... Subsurface Point-Source Watershed-and Regional Scale Methods Development Crosscutting ... Climate-Driven Ocean Changes Affect Estuaries ...

Global climate change is driving rapid distribution shifts in marine ecosystems; these are well established for lower trophic levels, but are harder to quantify for migratory top predators. By analysing a 25-year sightings-based dataset, we found evidence for rapid northwards range expansion of the critically endangered Balearic shearwater Puffinus mauretanicus in northeast ...

Lake Yoa is a perennial lake entirely fed by groundwater and located in the Saharan desert of Northern Chad. It contains a unique continuous and high-resolution record of the climate history of the eastern Sahara for the last 6000 years (Kr�pelin et al. 2008). Analyses of aquatic and terrestrial paleoecosystems revealed a slow and progressive drying of the region since mid-Holocene (Kr�pelin ...

In the past three decades, climate change has become a pronounced driver of ecosystem change. Changes in phenology, range shift of species, and increases in disturbances such as wildfires have all reflected ecosystem scales responses to a warming biosphere. There have also been abrupt, nonlinear cha...

). Catastrophic thresholds are of tremendous relevance to ecology and ecosystem management because they signify for understanding gradual and abrupt behavior in both terrestrial and aquatic ecosystems (Scheffer 2009). Lockwood and effectiveness of resilience- based ecosystem management. This will require

Recent ecological research has uncovered examples of ecosystems that suddenly and sometimes catastrophically change in their composition and in their dynamics in response to incremental changes in external pressure. The possibility of such abrupt changes can have dire consequence...

... of alternating transgressive and highstand systems tracts. Moderate amplitude 4th-order cyclicity generated numerous 3�10 m cycles with repetitive gradual and abrupt facies transitions, which result in a c...

Tropical montane biome migration patterns in the northern Andes are found to be coupled to glacial-induced mean annual temperature (MAT) changes; however, the accuracy and resolution of current records are insufficient to fully explore their magnitude and rates of change. Here we present a ~60-year resolution pollen record over the past 284 000 years from Lake F�quene (5� N) in Colombia. This ...

We report new archeointensity results from Iranian and Syrian archeological excavations dated from the second millennium BC. These high-temperature magnetization data were obtained using a laboratory-built triaxial vibrating sample magnetometer. Together with our previously published archeointensity results from Mesopotamia, we constructed a rather detailed geomagnetic field intensity variation ...

Because individual species can play key roles, the loss of species through extinction or their gain through colonization can cause major changes in ecosystems. For almost 20 years after kangaroo rats were experimentally removed from a Chihuahuan desert ecosystem in the United States, other rodent species were unable to compensate and use the available ...

In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for events in the remote past, and it is even more difficult to predict if and ...

In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for events in the remote past, and it is even more difficult to predict if and ...

Records of past climates contained in ice cores, ocean sediments, and other archives show that large, abrupt, widespread climate changes have occurred repeatedly in the past. These changes were especially prominent during the cooling into and warming out of the last ice age, but persisted into the modern warm interval. Changes have especially affected water availability in ...

Ecosystems can alternate suddenly between contrasting persistent states due to internal processes or external drivers. It is important to understand the mechanisms by which these shifts occur, especially in exploited ecosystems. There have been several abrupt marine ecosystem shifts attributed either to fishing, ...

Ecosystems can alternate suddenly between contrasting persistent states due to internal processes or external drivers. It is important to understand the mechanisms by which these shifts occur, especially in exploited ecosystems. There have been several abrupt marine ecosystem shifts attributed either to fishing, ...

During the 21st century, climate-driven changes in fire regimes are expected to be a key agent of change in forest ecosystems of the western USA. Carbon (C) sequestration is an ecosystem service that is sensitive to increases in fire area, and C losses from fire create a positive feedback on the climate system. Identifying forest ...

Mountain regions are uniquely sensitive to changes in climate, and are especially vulnerable to climate effects acting on many biotic systems and the physical settings. Because mountain regions serve as sources of needed natural resources (e.g., water, forests) and as foundations for desired human activities (e.g., tourism, places to live), changes in mountain systems cascade into issues of ...

Current global patterns of terrestrial ecosystem form and process are now predominantly anthropogenic as a result of land use and other direct human interactions with ecosystems. This study investigates anthropogenic transformation of the terrestrial biosphere over the course of the industrial revolution by mapping and characterizing global transitions ...

Abrupt and rapid ecosystem shifts (where major reorganizations of food-web and community structures occur), commonly termed regime shifts, are changes between contrasting and persisting states of ecosystem structure and function. These shifts have been increasingly reported for exploited marine ecosystems around ...

Large, deep lakes offer a unique resource for the study of the interaction of the atmosphere and aquatic biogeochemical cycles. The remarkable properties of Crater Lake result in the vertical stratification of the ecosystem reminiscent of pelagic marine systems. This ultraoligotrophic lake provides a powerful natural laboratory to study the coupling of biological processes, ...

One goal of interdisciplinarity is to develop a more holistic understanding of a set of interlinked, complex system processes. Studies rarely couple both a mechanistic understanding of individual processes with their coupled influence on the entire system structure, yet the prospects for climate driven changes in western river systems provide justification ...

Northern South America presents a diverse array of nonforest or savanna-like ecosystems that are patchily distributed. The distribution of these open habitats has been quite dynamic during Quaternary glacial-interglacial cycles; yet, the relevance of climatically driven vicariance events to the diversification of nonforest Amazonian ...

The Great Plains landscape is less topographically complex than most other regions within North America, but diverse aquatic ecosystems, such as playas, pothole lakes, ox-bow lakes, springs, groundwater aquifers, intermittent and ephemeral streams, as well as large rivers and wetlands, are highly dynamic and responsive to extreme climatic fluctuations. We review the evidence ...

High-resolution seismic reflection records and well logs from the Santa Barbara Channel suggest that large parts of the Pleistocene succession records climate variability on orbital to sub-orbital scales with remarkable sensitivity, much like the well-studied sediments of the last glacial cycle (ODP Site 893). Spectral analysis of seismic reflection data and gamma ray logs from stratigraphically ...

Climate variation affects surface ocean processes and the production of organic carbon, which ultimately comprises the primary food supply to the deep-sea ecosystems that occupy ?60% of the Earth's surface. Warming trends in atmospheric and upper ocean temperatures, attributed to anthropogenic influence, have occurred over the past four decades. Changes in upper ocean ...

Coral reef ecosystems, often referred to as �marine rainforests,� concentrate the most diverse life in the oceans. Red Sea reef dwellers are adapted in a very warm environment, fact that makes them vulnerable to further and rapid warming. The detection and understanding of abrupt temperature changes is an important task, as ...

We present a high-resolution and independently dated multiproxylake sediment record from the paleolake at Les �chetsin southeastern France that displays synchronous changes inindependent limnic and terrestrial ecosystem proxies, in concertwith millennial-scale climate oscillations during the last glacialperiod. Distinct lake-level fluctuations, low lake organic ...

Ecosystem stewardship is an action-oriented framework intended to foster the social-ecological sustainability of a rapidly changing planet. Recent developments identify three strategies that make optimal use of current understanding in an environment of inevitable uncertainty and abrupt change: reducing the magnitude of, and exposure and sensitivity to, ...

Validation study of the daily time-step SEVER-DGVM fire module, at global and regional scale, over the 1997-2006 period is presented. Model-estimated burned areas and emissions are compare to the Global Fire Emission Database version 2 (GFED), derived from satellite observations. SEVER-Fire reproduces the main features of climate driven inter-annual fire ...

The major nutrients nitrate and phosphate have one of the strongest correlations in the sea, with a slope similar to the average nitrogen (N) to phosphorus (P) content of plankton biomass (N/P = 16:1). The processes through which this global relationship emerges despite the wide range of N/P ratios at the organism level are not known. Here we use an ocean circulation model and observed nutrient ...

The issue-focused, peer-reviewed article explains how the environment plays a major role in the evolution of species by: dramatic environmental changes triggering extinction as well as speciation, species arising after splitting from an ancestral species when they acquire new adaptations to a changing environment, and species stabilizing for millions of years followed by ...

followed by an abrupt and persistent biomass decline. The series from Tampa Bay suggests patterns Chesapeake Bay 8.1C Ringk�bing Fjord Tampa Bay 8 Fig. 1 Examples of Chl-a time series in estuarine.aspx); Ringk�bing Fjord (data provided by J.K. Petersen (Petersen et al. 2008)); and Tampa Bay site 8 (data provided

: Forest carbon cycling in northern lower Michigan Mixed-deciduous forests, such as those at UMBS ecosystems to young,mixed deciduous forests, abruptly changing their successional status. We now con- sider pattern of net C uptake and loss has been well documented in temperate deciduous forests (Schmid et al

Center, Reston, VA 20192; �Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964). Assemblage structure and diversity are clearly disturbed during centennial�millennial scale cooling events cooling events (HCE) 0�8 defined by Bond et al. (22, 23), the Younger Dryas (YD), the Inter-Aller�d Cold

The palynologically defined Cretaceous-Tertiary boundary in the western interior of North America occurs at the top of an iridium-rich clay layer. The boundary is characterized by the abrupt disappearance of certain pollen species, immediately followed by a pronounced, geologically brief change in the ratio of fern spores to angiosperm pollen. The occurrence of these changes ...

Recent research on deep-sea sediment cores suggests that the structure and diversity of deep-sea ecosystems exhibit greater instability over millennial and centennial timescales than previously realized. Centennial scale ecosystem shifts during the last deglaciation (Termination 1, 18-11.5 ka) and the Holocene (11.5 ka to recent) have been discovered using ...