Landscape Partnership Resources Library
Coupling of Vegetation Growing Season Anomalies and Fire Activity with Hemispheric and Regional-Scale Climate Patterns in Central and East Siberia
An 18-yr time series of the fraction of absorbed photosynthetically active radiation (fAPAR) taken in by the green parts of vegetation data from the NOAA Advanced Very High Resolution Radiometer (AVHRR) instrument series was analyzed for interannual variations in the start, peak, end, and length of the season of vegetation photosynthetic activity in central and east Siberia. Variations in these indicators of seasonality can give important information on interactions between the biosphere and atmosphere. A second-order local moving window regression model called the “camelback method” was developed to determine the dates of phenological events at subcontinental scale. The algorithm was validated by comparing the estimated dates to phenological field observations. Using spatial correlations with temperature and precipitation data and climatic oscillation indices, two geographically distinct mechanisms in the system of climatic controls of the biosphere in Siberia are postulated: central Siberia is controlled by an “Arctic Oscillation–temperature mechanism,” while east Siberia is controlled by an “El Niño–precipitation mechanism.” While the analysis of data from 1982 to 1991 indicates a slight increase in the length of the growing season for some land-cover types due to an earlier beginning of the growing season, the overall trend from 1982 to 1999 is toward a slightly shorter season for some land-cover types caused by an earlier end of season. The Arctic Oscillation tended toward a more positive phase in the 1980s leading to enhanced high pressure system prevalence but toward a less positive phase in the 1990s. The results suggest that the two mechanisms also control the fire regimes in central and east Siberia. Several extreme fire years in central Siberia were associated with a highly positive Arctic Oscillation phase, while several years with high fire damage in east Siberia occurred in El Niño years. An analysis of remote sensing data of forest fire partially supports this hypothesis VOLUME 20
Aeolian process effects on vegetation communities in an arid grassland ecosystem
Many arid grassland communities are changing from grass dominance to shrub dominance, but the mechanisms involved in this conversion process are not completely understood. Aeolian processes likely contribute to this conversion from grassland to shrubland. The purpose of this research is to provide information regarding how vegetation changes occur in an arid grassland as a result of aeolian sediment transport. The experimental design included three treatment blocks, each with a 25 × 50 m area where all grasses, semi-shrubs, and perennial forbs were hand removed, a 25 × 50 m control area with no manipulation of vegetation cover, and two 10 × 25 m plots immediately downwind of the grass-removal and control areas in the prevailing wind direction, 19◦ north of east, for measuring vegetation cover. Aeolian sediment flux, soil nutrients, and soil seed bank were monitored on each treatment area and downwind plot. Grass and shrub cover were measured on each grass-removal, control, and downwind plot along continuous line transects as well as on 5 × 10 m subplots within each downwind area over four years following grass removal. On grass-removal areas, sediment flux increased significantly, soil nutrients and seed bank were depleted, and Prosopis glandulosa shrub cover increased compared to controls. Additionally, differential changes for grass and shrub cover were observed for plots downwind of vegetation-removal and control areas. Grass cover on plots downwind of vegetation-removal areas decreased over time (2004–2007) despite above average rainfall throughout the period of observation, while grass cover increased downwind of control areas; P. glandulosa cover increased on plots downwind of vegetation-removal areas, while decreasing on plots downwind of control areas. The relationships between vegetation changes and aeolian sediment flux were significant and were best described by a logarithmic function, with decreases in grass cover and increases in shrub cover occurring with small increases in aeolian sediment flux
DO CARBON OFFSETS WORK? THE ROLE OF FOREST MANAGEMENT IN GREENHOUSE GAS MITIGATION
As forest carbon offset projects become more popular, professional foresters are providing their expertise to support them. But when several members of the Society of American Foresters questioned the science and assumptions used to design the projects, the organization decided to convene a task force to examine whether these projects can provide the intended climate benefits.The authors emphasize the carbon-storage benefits of using wood products in place of nonrenewable, energy-intensive materials and using woodbased energy instead of fossil fuels.
Adaptation: Planning for Climate Change and Its Effects on Federal Lands
National forest managers are charged with tackling the effects of climate change on the natural resources under their care. The Forest Service National Roadmap for Responding to Climate Change and the Climate Change Performance Scorecard require managers to make significant progress in addressing climate change by 2015. To help land managers meet this challenge, Forest Service scientists conducted three case studies on national forests and adjacent national parks and documented a wide range of scientific issues and solutions. They summarized the scientific foundation for climate change adaptation and made the information accessible to land managers by creating a climate change adaptation guidebookand web portal. Case study teams discovered that collaboration among scientists and land managers is crucial to adaptation planning, as are management plans targeted to the particular ecosystem conditions and management priorities of each region. Many current management practices are consistent with climate change adaptation goals. Because timely implementation is critical, strategies are in development at the national level to speed the implementation of science-based climate change adaptation processes in national forests throughout the country.
Ecosystem Service Markets 101: Supply and Demand for Nature
Establishing markets for ecosystem services—the benefits that nature provides, such as clean air, water, and wildlife habitat—has gained traction in some circles as a way to finance the conservation of these public goods. Market influences on supply and demand work in tandem to encourageecosystem protection. Jeff Kline and Trista Patterson, scientists with the Pacific Northwest (PNW) Research Station, have identified several criteria needed for ecosystem service markets to achieve their potential. These include regulatory limits on environmental damage, ecosystem services that are amenable to trading, and manageable transaction costs related to administering market programs and the necessary measuring and monitoring of marketed resources. If these criteria are not met, other conservation methods such as conservation easements, landowner incentive programs for environmental enhancement or protection, or taxes on environmental damage may be more effective. Discussions about ecosystem services often focus on increasing supply— storing more carbon or delivering more water, for example. However, net pressures on ecosystems can also be reduced by addressing consumption. Many energy efficiencies can be achieved by promoting awareness, informed choices, and behavior change. The PNW Research Station is examining both supply and demand approaches to ecosystem protection by encouraging the development of ecosystem services markets and identifying ways to reduce its own environmental footprint.
All Downhill From Here?
Biologists say climate change may already be affecting high-mountain ecosystems around the world, where plants and animals adapted to cold, barren conditions now face higher temperatures and a surge of predators and competitors
Changes in Climatic Water Balance Drive Downhill Shifts in Plant Species’ Optimum Elevations
Uphill shifts of species’ distributions in response to historical warming are well documented, which leads to widespread expectations of continued uphill shifts under future warming. Conversely, downhill shifts are often considered anomalous and unrelated to climate change. By comparing the altitudinal distributions of 64 plant species between the 1930s and the present day within California, we show that climate changes have resulted in a significant downward shift in species’ optimum elevations. This downhill shift is counter to what would be expected given 20th-century warming but is readily explained by species’ niche tracking of regional changes in climatic water balance rather than temperature. Similar downhill shifts can be expected to occur where future climate change scenarios project increases in water availability that outpace evaporative demand.
Defaunation in the Anthropocene
We live amid a global wave of anthropogenically driven biodiversity loss: species and population extirpations and, critically, declines in local species abundance. Particularly, human impacts on animal biodiversity are an under-recognized form of global environmental change. Among terrestrial vertebrates, 322 species have become extinct since 1500, and populations of the remaining species show 25% average decline in abundance. Invertebrate patterns are equally dire: 67% of monitored populations show 45% mean abundance decline. Such animal declines will cascade onto ecosystem functioning and human well-being. Much remains unknown about this “Anthropocene defaunation”; these knowledge gaps hinder our capacity to predict and limit defaunation impacts. Clearly, however, defaunation is both a pervasive component of the planet’s sixth mass extinction and also a major driver of global ecological change 25 JULY 2014 • VOL 345 ISSUE 6195
Changes in Wind Pattern Alter Albatross Distribution and Life-History Traits
Westerly winds in the Southern Ocean have increased in intensity and moved poleward. Using long-term demographic and foraging records, we show that foraging range in wandering albatrosses has shifted poleward in conjunction with these changes in wind pattern, while their rates of travel and flight speeds have increased. Consequently, the duration of foraging trips has decreased, breeding success has improved, and birds have increased in mass by more than 1 kilogram. These positive consequences of climate change may be temporary if patterns of wind in the southern westerlies follow predicted climate change scenarios. This study stresses the importance of foraging performance as the key link between environmental changes and population processes.
Coupling of CO2 and Ice Sheet Stability Over Major Climate Transitions of the Last 20 Million Years
During the Middle Miocene, when temperatures were ~3° to 6°C warmer and sea level 25 to 40 meters higher than present, pCO2 was similar to modern levels.
Carbon Market Lessons and Global Policy Outlook
Summary: Ongoing work on linking markets and mixing policies builds on successes and failures in pricing and trading carbon. Closing sentence, 1st paragraph: Are carbon markets seriously challenged or succeeding and on the rise?
Assemblage Time Series Reveal Biodiversity Change but Not Systematic Loss
The extent to which biodiversity change in local assemblages contributes to global biodiversity loss is poorly understood. We analyzed 100 time series from biomes across Earth to ask how diversity within assemblages is changing through time. We quantified patterns of temporal a diversity, measured as change in local diversity, and temporal b diversity, measured as change in community composition. Contrary to our expectations, we did not detect systematic loss of a diversity. However, community composition changed systematically through time, in excess of predictions from null models. Heterogeneous rates of environmental change, species range shifts associated with climate change, and biotic homogenization may explain the different patterns of temporal a and b diversity. Monitoring and understanding change in species composition should be a conservation priority.
Climate Change Conversations
THE THOUSANDS OF PRESENTATIONS AT NEXT WEEK’S MEETING OF THE AMERICAN CHEMICAL SOCIETY (ACS) in New Orleans exemplify one of the many ways scientists converse among themselves about the most recent advances in science. Science and technology continue to reshape the world we live in, and appreciating how these changes, both intended and unintended, come about is a necessity for all citizens in a democratic society. Scientists have a responsibility to help their fellow citizens understand what science and technology can and cannot do for them
Monsoon Melee
The rhythms of life across South Asia depend on the Indian monsoon. Climate scientists are locking horns over the cause of the summer deluges
Hell and High Water: PracticeRelevant Adaptation Science
Adaptation requires science that analyzes decisions, identifies vulnerabilities, improves foresight, and develops options
A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
Enhanced Seasonal Exchange of CO2 by Northern Ecosystems Since 1960
Seasonal variations of atmospheric carbon dioxide (CO2) in the Northern Hemisphere have increased since the 1950s, but sparse observations have prevented a clear assessment of the patterns of long-term change and the underlying mechanisms. We compare recent aircraft-based observations of CO2 above the North Pacific and Arctic Oceans to earlier data from 1958 to 1961 and find that the seasonal amplitude at altitudes of 3 to 6 km increased by 50% for 45° to 90°N but by less than 25% for 10° to 45°N. An increase of 30 to 60% in the seasonal exchange of CO2 by northern extratropical land ecosystems, focused on boreal forests, is implicated, substantially more than simulated by current land ecosystem models. The observations appear to signal large ecological changes in northern forests and a major shift in the global carbon cycle.
Biotic Multipliers of Climate Change
A focus on species interactions may improve predictions of the effects of climate change on ecosystems.
Carbon Storage with Benefits
Biochar—a material related to charcoal—has the potential to benefit farming as well as mitigate climate change.
Climate Outlook Looking Much The Same, or Even Worse
Climate scientists have been feverishly preparing analyses for inclusion in the fifth climate assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) due out in 2013. At the meeting, they gave colleagues a peek at where climate science stands 5 years after their last push to inform the authoritative international evaluation . The climate models are bigger and more sophisticated than ever, speakers reported, but they are yielding the same wide range of possible warming and precipitation changes as they did 5 years ago. But when polled on other areas of concern, researchers say they see more trouble ahead than the previous IPCC assessment had, though less than some scientists had feared
