Impact of Carbon Storage Through Restoration of Drylands on the Global Carbon Cycle

   Using estimates of land suitable for restoration in woodlands, grasslands, and deserts, as well as estimates of the rate at which restoration can proceed, we estimate that carbon storage in these biomes can range up to 0.8 billion tons of carbon per year (Gt C/yr), for a combination of land management strategies. This corresponds to a reduction in atmospheric buildup of 0.5 Gt C/yr, which represents up to 15% of the average annual atmospheric carbon buildup in the next century, 3.5 Gt C/yr, assuming the IPCC 92d scenario. A global strategy for reducing atmospheric carbon dioxide concentration will require the implementation of multiple options. The advantage of carbon storage in restored drylands is that it comes as a side benefit to programs that are also justifiable in terms of land management.     

Mapping Grazing-Induced Degradation in a Semi-Arid Environment: A Rapid and Cost Effective Approach for Assessment and Monitoring

Improved techniques for measuring and monitoring the state of biodiversity are required for reporting on national obligations to international and regional conservation institutions. Measuring the extent of grazing-related degradation in semi-arid ecosystems has proved difficult. Here we present an accurate and cost-effective method for doing this, and apply it in a South African semi-arid region that forms part of a globally significant biodiversity hotspot. We grouped structurally and functionally similar vegetation units, which were expert-mapped at the 1:50,000 scale, into four habitat types, and developed habitat-specific degradation models. We quantified degradation into three categories, using differences between dry and wet season values of the Normalized Difference Vegetation Index (NDVI) for the three succulent karoo habitats, and the difference between maximum and mean NDVI values for the subtropical thicket habitat. Field evaluation revealed an accuracy of 86%. Overall, degradation was high: 24% of the study area was modeled as severely degraded, and only 9% as intact. Levels of degradation were highest for bottomland habitats that were most exposed to grazing impacts. In sharp contrast to our methods, a widely used, broad-scale and snapshot assessment of land cover in South Africa was only 33% accurate, and it considerably underestimated the extent of severely degraded habitat in the study area. While our approach requires a multidisciplinary team, and in particular expert knowledge on the characteristics and spatial delimitation of vegetation types, it is repeatable, rapid, and relatively inexpensive. Consequently, it holds great promise for monitoring and evaluation programs in semi-arid ecosystems, in Africa, and beyond.     

Land Use Change and Land Degradation in Southeastern Mediterranean Spain

The magnitude of the environmental and social consequences of soil erosion and land degradation in semiarid areas of the Mediterranean region has long been recognized and studied. This paper investigates the interrelationship between land use/cover (LULC) changes and land degradation using remotely sensed and ancillary data for southeastern Spain. The area of study, the Xaló River catchment situated in the north of the Alicante Province, has been subjected to a number of LULC changes during the second half of the 20th century such as agricultural abandonment, forest fires, and tourist development. Aerial photographs dating back to 1956 were used for the delineation of historic LULC types; Landsat ETM+ data were used for the analysis and mapping of current conditions. Two important indicators of land degradation, namely, susceptibility to surface runoff and soil erosion, were estimated for the two dates using easily parametrizable models. The comparison of 1956 to 2000 conditions shows an overall “recuperating” trend over the catchment and increased susceptibility to soil erosion only in 3% of the catchment area. The results also identify potential degradation hot-spots where mitigation measures should be taken to prevent further degradation. The readily implemented methodology, based on modest data requirements demonstrated by this study, is a useful tool for catchment to regional scale land use change and land degradation studies and strategic planning for environmental management.     

Land use change and carbon exchange in the tropics: II. Estimates for the entire region

Determining the effect of tropical land use on the carbon dioxide (CO₂) content of the atmosphere requires: (a) estimates of the rates of land use change, (b) estimates of the difference between the carbon stored in forests and that stored in pastures and cultivated fields, and (c) a consideration of the fate of carbon stored in the cleared vegetation. The first article of this series analyzed land use in four tropical countries and estimated the carbon released to the atmosphere as a consequence of changes in land use. This article estimates the carbon released from the entire tropical region based on the two published studies of land use change for the tropics as a whole that distinguish between temporary and permanent land use: Seiler and Crutzen (1980) and Lanly (1982). We combine these estimates with two estimates of the difference in carbon storage between forests and fields derived from Whittaker and Likens (1975) and Brown and Lugo (1982), and the two scenarios of the fate of cleared vegetation, developed in the previous article, to produce several complete sets of data describing the necessary parameters to calculate carbon exchange. These data sets, entered into our model, produce a range of estimates of the annual release of carbon from tropical vegetation in 1980 of from 0.6 to 1.8 BMT/year, with the more likely range being 0.9–1.2 BMT/year. Our preliminary analysis suggests that the release from tropical soils due to land use change adds about an additional 0.3 BMT C/year, so that the total release is probably between 1.2 and 1.5 BMT C/year. Peng and others (1983) reported that new models of the oceanic carbon cycle can accommodate at least 1.2 BMT C/year in 1980 from forests and soils. Our results indicate that, given the uncertainties in the size of both the biotic release and oceanic uptake, the global carbon budget may be balanced if there is no significant release from nontropical ecosystems due to land use change and all mature ecosystems are in collective equilibrium with the atmosphere.     

A land management history for central Queensland,Australia as determined from land-holder questionnaire and aerial photography

Features of the land management history over a 125,755 km(2) area of central Queensland, Australia were determined from a variety of sources. A random sample of 205 site locations provided the basis for determining trends in land use. Trends in vegetation clearing were determined using sequential aerial photography for the sample sites, revealing a steady rate averaging nearly 1% of the region per annum over 41 years. This measure of sustained clearing over a large region is higher than recently published clearing rates from South America. Land types have been selectively cleared with over 90% of the Acacia on clay land type having been cleared. A land-holder questionnaire pertaining to the random sites yielded a response rate of 71% and provided information on vegetation clearing, ploughing, tree killing (ring-barking or tree poisoning), and fire frequency, season and intensity. The land-holder responses were compared with independent data sources where possible and revealed no mis-information. However, land-holders may have been marginally less likely to respond if the sample area had been cleared, although this effect was not statistically significant. Ploughing and tree killing are variable depending on land type, but the former has affected about 40% of the Acacia on clay land type, effectively eliminating options for natural regrowth. The proportion of decade-site combinations that were reported as having no fires increased from 22% in the 1950s to an average of 42% for subsequent decades, although the reporting of more than one fire per decade has been relatively constant through the study period. The reporting of at least one fire per decade varies from 46% for the Acacia on sand land type to 77% for the Eucalypt on sand land type for decade-site combinations. Fires are more intense when associated with clearing than in uncleared vegetation, but the proportion of cool and hot fires is relatively constant between land types in uncleared vegetation. Nearly all fires reported were either in spring or summer and this seasonally restricted regime is probably at variance with Aboriginal fire regimes. This study describes the rapid transformation of central Queensland. This has yielded substantially increased agricultural production but may also result in a range of negative impacts and these are discussed.     

Changes in Soil Aggregate,Carbon, and Nitrogen Storages Following the Conversion of Cropland to Alfalfa Forage Land in the Marginal Oasis of Northwest China

Maintenance of soil organic carbon (SOC) is important for sustainable use of soil resources due to the multiple effects of SOC on soil nutrient status and soil structural stability. The objective of this study was to identify the changes in soil aggregate distribution and stability, SOC, and nitrogen (N) concentrations after cropland was converted to perennial alfalfa (Medicago sativa L. Algonguin) grassland for 6 years in the marginal oasis of the middle of Hexi Corridor region, northwest China. Significant changes in the size distribution of dry-sieving aggregates and water-stable aggregates, SOC, and N concentrations occurred after the conversion from crop to alfalfa. SOC and N stocks increased by 20.2% and 18.5%, respectively, and the estimated C and N sequestration rates were 0.4 Mg C ha⁻¹ year⁻¹ and 0.04 Mg N ha⁻¹ year⁻¹ following the conversion. The large aggregate (>5 mm) was the most abundant dry aggregate size fraction in both crop and alfalfa soils, and significant difference in the distribution of dry aggregates between the two land use types occurred only in the >5 mm aggregate fraction. The percentage of water-stable macroaggregates (>2, 2–0.25 mm) and aggregate stability (mean weight diameter of water-stable aggregates, WMWD) were significantly higher in alfalfa soils than in crop soils. There was a significant linear relationship between total SOC concentration and aggregate parameters (mean weight diameter) for alfalfa soils, indicating that aggregate stability was closely associated with increased SOC concentration following the conversion of crops to alfalfa. The SOC and N concentrations and the C/N ratio were greatest in the >2 mm water-stable aggregates and the smallest in the 0.25–0.05 mm aggregates in crop and alfalfa soils. For the same aggregate, SOC and N concentrations in aggregate fractions increased with increasing total SOC and N concentrations. The result showed that the conversion of annual crops to alfalfa in the marginal land with coarse-texture soils can significantly increase SOC and N stocks, and improve soil structure.     

Forest Cover Change,Physiography, Local Economy,and Institutions in a Mountain Watershed in Nepal

This study assessed changes in forest cover in a mountain watershed in central Nepal between 1976 and 2000 by comparing classified satellite images coupled by GIS analyses, and examined the association of forest change with major physiographic, economic, and local forest governance parameters. The results showed an increase in forested area (forest plus shrublands) by 7.6% during 1976–2000. Forest dynamism (changes including improvement, deterioration, gain, and loss) was highest in low-elevation, south-facing and less-steep slopes that were closer to roads. Proportionately the highest net improvement and gain to forested area also took place in those locations. Forest degradation occurred at twice the rate of improvement in high elevation areas (> 2300 m). Forests located in urban and semiurban areas (i.e., a market-oriented economy) experienced a proportionately higher amount of net improvement and gain than forests in rural areas (i.e., a subsistence economy). Among the three governance arrangements, proportionately the highest net improvement and gain took place in semigovernment forests (forested area legally under the forest department but with de facto control and claim of ownership by local communities and/or municipality) followed by formalized community forests (including leasehold). Government forests, which were mostly found in the southern high mountains and had virtually open access, remained relatively stable during the study period. Over 50% of the watershed forests have not come under community-based management despite favorable policy and more than two decades of government intervention with continuous donor support. The findings indicate that the present one size fits all approach of community forest handover policy in Nepal needs rethinking to accommodate biophysical and socioeconomic variations across the country.     

Degradation–environment–society spiral: A spatial auto‐logistic model in Thailand

In this contemporary interpretation of the widespread land degradation problem in Southeast Asia, it is hypothesized that spatial interplay of environmental and socioeconomic predictors determines the occurrence of land degradation. Village surveys, remote sensing and spatial auto‐logistic modelling of the relationship between degradation and land use dynamics in Lam Phra Phloeng watershed of Thailand enabled 80.2% of land to be classified correctly in terms of the presence or absence of erosion and explained 53.2% of the total variation. Cultivation and dependence on agriculture for livelihood positively and significantly affect degradation. Lack of access to institutional credit and land titles significantly increased the probability of occurrence of degradation. On the other hand, education and social cohesion are negatively associated with the occurrence of degradation. The Relative Operating Characteristic (ROC) curve was used to measures the performance of the model. The calculated area under the curve (0.879) suggests that significant predictor variables in the model can be confidently used to forecast the likelihood of occurrence of degradation and thus to identify priority areas for intervention. Policies to reduce land degradation should include measures to reduce pressure on the land, including alternative income sources. Policies could mobilize capital to invest in encouraging nature‐based tourism and other off‐farm income options.     

Land use and management in the People's Republic of China

Widespread disregard for essential principles of sound environmental management and protection during the three decades of Communist rule prior to 1980 have exacerbated traditional shortages of good arable land and productive forest cover in the People's Republic of China. The government's policies have also drastically reduced valuable freshwater surfaces, caused extensive grassland deterioration and soil erosion, and brought about many local and regional climatic changes. However, new policies put into effect recently are attempting to reverse these trends with a sound ecosystemic approach to land management.     

Status and management of watersheds in the Upper Pokhara Valley,Nepal

Contributing to the debate on the causes of Himalayan environmental degradation, the status and management of four watersheds in the Upper Pokhara Valley were studied using information available from land use analysis, household surveys conducted in 1989 and 1992, deliberations held with villagers, and field observations. Accordingly, areas under forests and grazing lands were found being depleted at relatively high rates between 1957 and 1978 due mainly to the government policy of increasing national revenue by expansion of agricultural lands, nationalization of forests, steadily growing population, and dwindling household economy. Despite the steady growth of population, this process had remarkably slackened since 1978, owing primarily to remaining forests being located in very, steep slopes and implementation of the community forestry program. Forests with relatively sparase tree density, however, and grazing lands in the vicinity of settlements have been undergoing degradation due to fuelwood and fodder collection and livestock grazing. In many instances, this is aggravated by weak resource management institutions. Being particularly aware of the economic implication of land degradation, farmers have adopted assorted land management practices. Still a substantial proportion ofbari lands in the hill slopes is vulnerable to accelerating degradation, as the arable cropping system is being practiced there as well. The perpetuation of the local subsistence economy is certain to lead, to a further deterioration of the socioeconomic and environmental conditions of watersheds. To facilitate environmental conservation and ecorestructuring for sustainable development, a broad watershed management strategy is outlined with focus on alleviating pressure on natural resources.     

Changes in flood-plain vegetation and land use along the Missouri River from 1826 to 1972

Changes in vegetation and land use since 1826 were evaluated along the 800 kilometer portion of the Missouri River flood-plain that extends across the State of Missouri using County Land Office Survey records for 1826 and aerial photos for 1937, 1958, and 1972. The combined results show a decline in flood-plain forest coverage from 76% in 1826 to 13% in 1972; cultivated land increased from 18% to 83% during the same time. Uncultivated-unforested areas increased from 6% in 1826 to 27% in 1937, then declined to 1% in 1972; these changes occurred coincident with extensive bank-stabilization and channelization activities initiated in 1912 by the U.S. Army Corps of Engineers. Riverbank stabilization activity since that time may account for the increased rate of decline in flood-plain forests from 0.25% per year between 1826 and 1937 to 1.6% per year between 1937 and 1972.The overall species composition of the 1826 flood-plain forests was found to be most similar to mature forest stands evaluated in 1972; similar frequencies in 1826 and 1972 occurred for hackberry (Celtis occidentalis; 80% in 1826, 83% in 1972), elm (Ulmus spp.; 80% and 83%), and sycamore (Platanus occidentalis; 57% and 50%). Pawpaw (Asimina triloba), found only in mature flood-plain forests in 1972, was recorded along 54% of the 1826 section lines.These combined data indicate (1) that pre-settlement flood-plain forests were extensive and included frequent, mature stands, (2) that in certain areas substantial portions of the flood-plain were in cultivation prior to extensive riverbank stabilization and channelization, and (3) that increased flood-plain forest clearing occurred coincident with increased bank-stabilization activities.     

Land-cover change in upper Barataria Basin estuary,Louisiana, 1972-1992: increases in Wetland area

The Barataria Basin, Louisiana, USA, is an extensive wetland and coastal estuary system of great economic and intrinsic value. Although high rates of wetland loss along the coastal margin of the Barataria Basin have been well documented, little information exists on whether freshwater wetlands in the upper basin have changed. Our objectives were to quantify land-cover change in the upper basin over 20 years from 1972–1992 and to determine land-cover transition rates among land-cover types. Using 80-m resolution Landsat MSS data from the North American Landscape Characterization (NALC) data archive, we classified images from three time steps (1972, 1985, 1992) into six land-cover types: agriculture, urban, bottomland hardwood forest, swamp forest, freshwater marsh, and open water. Significant changes in land cover occurred within the upper Barataria Basin over the study period. Urban land increased from 8% to 17% of the total upper basin area, primarily due to conversions from agricultural land, and to a lesser degree, bottomland forest. Swamp forest increased from 30% to 41%, associated with conversions from bottomland hardwood forest and freshwater marsh. Overall, bottomland forest decreased 38% and total wetland area increased 21%. Within the upper Barataria, increases in total wetland area may be due to land subsidence. Based on our results, if present trends in the reduction of bottomland forest land cover were to continue, the upper Barataria Basin may have no bottomland hardwood forests left by the year 2025, as it is subjected to multiple stressors both in the higher elevations (from urbanization) and lower elevations (most likely from land subsidence). These results suggest that changes in the upper freshwater portions of coastal estuaries can be large and quite different from patterns observed in the more saline coastal margins.     

Snowmelt Runoff and Water Yield Along Elevation and Temperature Gradients in California’s Southern Sierra Nevada1

Hunsaker, Carolyn T., Thomas W. Whitaker, and Roger C. Bales, 2012. Snowmelt Runoff and Water Yield Along Elevation and Temperature Gradients in California’s Southern Sierra Nevada. Journal of the American Water Resources Association (JAWRA) 48(4): 667‐678. DOI: 10.1111/j.1752‐1688.2012.00641.x Abstract: Differences in hydrologic response across the rain‐snow transition in the southern Sierra Nevada were studied in eight headwater catchments – the Kings River Experimental Watersheds – using continuous precipitation, snowpack, and streamflow measurements. The annual runoff ratio (discharge divided by precipitation) increased about 0.1 per 300 m of mean catchment elevation over the range 1,800‐2,400 m. Higher‐elevation catchments have lower vegetation density, shallow soils with rapid permeability, and a shorter growing season when compared with those at lower elevations. Average annual temperatures ranged from 6.8°C at 2,400 m to 8.6 at 1,950 m elevation, with annual precipitation being 75‐95% snow at the highest elevations vs. 20‐50% at the lowest. Peak discharge lagged peak snow accumulation on the order of 60 days at the higher elevations and 20 to 30 days at the lower elevations. Snowmelt dominated the daily streamflow cycle over a period of about 30 days in higher elevation catchments, followed by a 15‐day transition to evapotranspiration dominating the daily streamflow cycle. Discharge from lower elevation catchments was rainfall dominated in spring, with the transition to evapotranspiration dominance being less distinct. Climate warming that results in a longer growing season and a shift from snow to rain would result in earlier runoff and a lower runoff ratio.     

Changes in Land Cover and Subsequent Effects on Lower Fraser Basin Ecosystems from 1827 to 1990

/ European settlement began in the Lower Fraser Basin (LFB) inwestern British Columbia in 1827 and has impacted the basin ecosystem in anumber of ways, especially affecting the vegetation. Using previouslypublished data, air photos, and other historical material for the area,estimates of land cover were made for the years prior to 1827 and for 1930and 1990. The area of coniferous forest changed from 71% prior to 1827to 50% in 1930 to 54% in 1990. However, prior to 1827, only27% of the forest would have been immature (<120 years old), while40% would have been immature in 1930 and 73% of the forest wasimmature in 1990. The amount of wetland area decreased from 10% to1% of the study area while urban and agricultural area increased to26% of the study area by 1990. The changes in land cover have hadadverse effects on soil, water, and air quality; aquatic life; and plant andanimal populations. Estimates of changes in net primary production andorganic soil carbon suggest a decline over the past 170 years, although thelatter rate of decrease has slowed since 1930. As human populations in theLower Fraser Basin continue to increase, the quality of air, water, and soilwill continue to decline unless measures are taken.KEY WORDS: Human impact; Land cover; Net primary productivity; Organiccarbon in soil     

Earthworms: nature’s chemical managers and detoxifying agents in the environment: an innovative study on treatment of toxic wastewaters from the petroleum industry by vermifiltration technology

Earthworms are justifying the beliefs of Great Russian scientist Dr. Anatoly Igonin who said they are????disinfecting, detoxifying, neutralizing, protective and productive??. Studies indicate that some species of earthworms can ??bio-accumulate, biodegrade or bio-transform?? any toxic chemicals including ??heavy metals??, ??organochlorine pesticide??, ??herbicides??, and the lipophilic organic micro-pollutants like ??polycyclic aromatic hydrocarbons?? (PAHs). Worm vermicasts, due to the presence of ??hydrophilic?? groups in the ??lignin contents?? and ??humus??, also provide wonderful sites for ??adsorption?? of heavy metals and chemical pollutants in wastewater. Vermifiltration of wastewater using waste-eater earthworms is a newly conceived novel technology with several economic and environmental advantages. The earthworm??s body and the their ??vermicast?? work as a ??biofilter?? removing BOD₅ by over 90?%, COD by 60?C80?%, TDSS by 90?C95?%, and toxic chemicals and pathogens from wastewater. This was a pioneering work done on an extremely ??toxic wastewater?? from the petroleum industry. It contained mixture of ??aliphatic?? and ??aromatic?? volatile petroleum hydrocarbons (C 10?CC 36) and ??organochlorines?? originating from the cooling liquids, waste engine and gear oil, waste transmission and brake fluid, grease, spilled petrol, and diesel oil. The aliphatic fraction contained cycloalkanes as well as a complex mixture of saturated toxic hydrocarbons. The aromatic fraction mainly consisted of PAHs, which are more toxic and persistent than the aliphatic part. The chemicals of concern were the total petroleum hydrocarbons (TPH), dichloromethane (DCM), dichloroethane (DCE), and t-butyl methyl ether (tBME). The tBME compound has raised global concern recently due to its high mobility and persistence in the environment and possible carcinogenicity. About 1,000 earthworms (species Eisenia fetida) were released in the soil of vermifilter bed. They not only tolerated and survived in the toxic petroleum environment but also bio-filtered and bio-remediated the dark-brown petroleum wastewater with a pungent smell into pale-yellow and odorless water indicating disappearance of all toxic hydrocarbons. The hydrocarbons C 10?CC 14 were reduced by 99.9?%, the C 15?CC 28 by 99.8?%, and the C 29?CC 36 by 99.7?% by earthworms.     

Remote sensing for land management and planning

The primary role of remote sensing in land management and planning has been to provide information concerning the physical characteristics of the land which influence the management of individual land parcels or the allocation of lands to various uses These physical characteristics have typically been assessed through aerial photography, which is used to develop resource maps and to monitor changing environmental conditions These uses are well developed and currently well integrated into the planning infrastructure at local, state, and federal levels in the United States.Many newly emerging uses of remote sensing involve digital images which are collected, stored, and processed automatically by electromechanical scanning devices and electronic computers Some scanning devices operate from aircraft or spacecraft to scan ground scenes directly; others scan conventional aerial transparencies to yield digital images. Digital imagery offers the potential for computer-based automated map production, a process that can significantly increase the amount and timeliness of information available to land managers and planners.Future uses of remote sensing in land planning and management will involve geographic information systems, which store resource information in a geocoded format. Geographic information systems allow the automated integration of disparate types of resource data through various types of spatial models so that with accompanying sample ground data, information in the form of thematic maps and/ or aerially aggregated statistics can be produced Key issues confronting the development and integration of geographic information systems into planning pathways are restoration and rectification of digital images, automated techniques for combining both quantitative and qualitative types of data in information-extracting procedures, and the compatibility of alternative data storage modes     

Land use change and population growth in the Morobe Province of Papua New Guinea between 1975 and 2000

The relation between human population growth and land use change is much debated. Here we present a case study from Papua New Guinea where the population has increased from 2.3 million in 1975 to 5.2 million in 2000. Since 85% of the population relies on subsistence agriculture, population growth affects agricultural land use. We assessed land use change in the Morobe province (33,933 km2) using topographic maps of 1975 and Landsat TM images of 1990 and 2000. Between 1975 and 2000, agricultural land use increased by 58% and population grew by 99%. Most new agricultural land was taken from primary forest and the forest area decreased from 9.8 ha person(-1) in 1975 to 4.4 ha person(-1) in 2000. Total population change and total land use change were strongly correlated. Most of the agricultural land use change occurred on Inceptisols in areas with high rainfall (>2500 mm year(-1)) on moderate to very steep slopes (10-56%). Agricultural land use changes in logged-over areas were in the vicinity of populated places (villages), and in close proximity to road access. There was considerable variation between the districts but districts with higher population growth also had larger increases in agricultural areas. It is concluded that in the absence of improved farming systems the current trend of increased agriculture with rapid population growth is likely to continue.     

Temporal Trends in the Spatial Distribution of Impervious Cover Relative to Stream Location

Use of impervious cover is transitioning from an indicator of surface water condition to one that also guides and informs watershed planning and management, including Clean Water Act (33 U.S.C. §1251 et seq.) reporting. Whether it is for understanding surface water condition or planning and management, impervious cover is most commonly expressed as summary measurement (e.g., percentage watershed in impervious cover). We use the National Land Cover Database to estimate impervious cover in the vicinity of surface waters for three time periods (2001, 2006, 2011). We also compare impervious cover in the vicinity of surface waters to watershed summary estimates of impervious cover for classifying the spatial pattern of impervious cover. Between 2001 and 2011, surface water shorelines (streams and water bodies) in the vicinity of impervious cover increased nearly 10,000 km. Across all time periods, approximately 27% of the watersheds in the continental United States had proximally distributed impervious cover, i.e., the percentage of impervious cover in the vicinity of surface waters was higher than its watershed summary expression. We discuss how impervious cover spatial pattern can be used to inform watershed planning and management, including reporting under the Clean Water Act.     

Using Satellite Fire Detection to Calibrate Components of the Fire Weather Index System in Malaysia and Indonesia

Vegetation fires have become an increasing problem in tropical environments as a consequence of socioeconomic pressures and subsequent land-use change. In response, fire management systems are being developed. This study set out to determine the relationships between two aspects of the fire problems in western Indonesia and Malaysia, and two components of the Canadian Forest Fire Weather Index System. The study resulted in a new method for calibrating components of fire danger rating systems based on satellite fire detection (hotspot) data. Once the climate was accounted for, a problematic number of fires were related to high levels of the Fine Fuel Moisture Code. The relationship between climate, Fine Fuel Moisture Code, and hotspot occurrence was used to calibrate Fire Occurrence Potential classes where low accounted for 3% of the fires from 1994 to 2000, moderate accounted for 25%, high 26%, and extreme 38%. Further problems arise when there are large clusters of fires burning that may consume valuable land or produce local smoke pollution. Once the climate was taken into account, the hotspot load (number and size of clusters of hotspots) was related to the Fire Weather Index. The relationship between climate, Fire Weather Index, and hotspot load was used to calibrate Fire Load Potential classes. Low Fire Load Potential conditions (75% of an average year) corresponded with 24% of the hotspot clusters, which had an average size of 30% of the largest cluster. In contrast, extreme Fire Load Potential conditions (1% of an average year) corresponded with 30% of the hotspot clusters, which had an average size of 58% of the maximum. Both Fire Occurrence Potential and Fire Load Potential calibrations were successfully validated with data from 2001. This study showed that when ground measurements are not available, fire statistics derived from satellite fire detection archives can be reliably used for calibration. More importantly, as a result of this work, Malaysia and Indonesia have two new sources of information to initiate fire prevention and suppression activities.     

Agricultural Land Use Effects on Sediment Loading and Fish Assemblages in Two Minnesota (USA) Watersheds

We examined the relationship between water quality and fish communities within two agricultural areas using a computer simulation model. Our analyses focused on a coolwater stream, Wells Creek in southeastern Minnesota, and a warmwater stream, the Chippewa River in western Minnesota. We used the Agricultural Drainage and Pesticide Transport (ADAPT) model in relation to land use to calculate instream suspended sediment concentrations using estimates of sediment delivery, runoff, baseflow and streambank erosion, and quantified the effects of suspended sediment exposure on fish communities. We predicted the effects of agricultural practices on stream fish communities under several possible land use scenarios, with reference to current conditions. Land use changes led to reductions in sediment loading of up to 84% in Wells Creek and 49% in the Chippewa River. The reduction in sediment loading across scenarios may be directly related to a reduction in runoff by about 35% in both study areas. We found a 98% decrease in lethal concentrations of suspended sediment on fish in Wells Creek with an increase in conservation tillage, riparian buffers, and permanent vegetative cover. However, the effects of suspended sediment did not significantly decrease in the Chippewa River. This difference between study areas was likely due to differences in tolerance to suspended sediment between coolwater and warmwater fish communities and differences in topography, runoff and bank erosion between the two streams. The Minnesota Cooperative Fish and Wildlife Research Unit is jointly sponsored by the US Geological Survey, the University of Minnesota, the Minnesota Department of Natural Resources, and the Wildlife Management Institute.