Since the launch of the first earth resources monitoring satellite, remote sensing imagery has been used to provide information on the progress of urbanization, and land cover and land use change. The launch of the first SPOT satellite marked a significant improvement in spatial and spectral resolution for discriminating individual targets and increased the potential to acquire more information regarding land cover and land use. This study aims to investigate the capability of using SPOT digital imagery for monitoring land use change in the urbanised catchment of Tuggeranong Creek in the Australia Capital Territory, and assess its effects on catchment hydrology. SPOT multispectral and panchromatic imagery was acquired over the study area for January 1987 and September 1990. This imagery was digitally processed and analysed using microBRIAN (MB) V3.01 software to derive information on land cover and land use within the catchment. Multi-temporal imagery was co-registered to a base map with sub-output pixel accuracy. In order to improve spatial resolution, the multispectral imagery was merged with panchromatic imagery acquired on the same day using HIS and HPF techniques. The HPF technique retained more integrity of the original multispectral data than did the HIS technique. Both HPF merged and unmerged (original) image sets were used to assess the possibility of using higher spatial resolution imagery in subsequent classification and change detection analysis. On the basis of statistical calculation, non-vegetation classification results were found to be consistent between merged and un-merged imagery, but not consistent for vegetation classes. The inconsistency was found to be the result of seasonal differences in phenology and sun angle. However more small sub-pixel sized features such as houses and lawns were identified using merged imagery. Regression differencing and post classification comparisons were performed on both merged and unmerged image sets to detect temporal changes which had occurred between both image dates. As expected, merged imagery led to more sub-pixel sized examples of change being highlighted using both the HPF and HIS techniques. However, errors associated with multi-temporal image registration, compounded by classification errors arising viI from seasonal differences, meant that the reliability of all identified incidences of change could not be validated. Nevertheless, post classification change detection was found to be the most useful approach for identifying the nature of change from one type of land use to another. The results of classification and change detection techniques were used to diagnose likely changes in catchment hydrology attributable to changes in land use. Preliminary hydrologic analyses found that catchment yield is more sensitive to changes in land use than runoff volume or peak flood discharge. This study confirms that SPOT imagery can be used for mapping and monitoring land use change in urban areas. SPOT imagery was found to be suitable for providing information on land use and land cover changes and assessing the likely hydrologic consequences of such change. The use of imagery from anniversary dates would further improve the reliability of hydrologic assessments based on remote sensing of land use change.

Water resources, in terms of quantity and quality, are significantly influenced by environmental changes, especially by climate and land use changes. The main objective of the present study is to project climate change impacts on the seasonal dynamics of water fluxes, spatial changes in water balance components as well as the future flood and low flow conditions in Germany. This study is based on the modeling results of the process-based eco-hydrological model SWIM (Soil and Water Integrated Model) driven by various regional climate scenarios on one hand. On the other hand, it is supported by statistical analysis on long-term trends of observed and simulated time series. In addition, this study evaluates the impacts of potential land use changes on water quality in terms of NO3-N load in selected sub-regions of the Elbe basin. In the context of climate change, the actual evapotransipration is likely to increase in most parts of Germany, while total runoff generation may decrease in south and east regions in the scenario period 2051-2060. Water discharge in all six studied large rivers (Ems, Weser, Saale, Danube, Main and Neckar) would be 8 – 30% lower in summer and autumn compared to the reference period (1961 – 1990), and the strongest decline is expected for the Saale, Danube and Neckar. The 50-year low flow is likely to occur more frequently in western, southern and central Germany after 2061 as suggested by more than 80% of the model runs. The current low flow period (from August to September) may be extended until the late autumn at the end of this century. Higher winter flow is expected in all of these rivers, and the increase is most significant for the Ems (about 18%). No general pattern of changes in flood directions can be concluded according to the results driven by different RCMs, emission scenarios and multi-realizations. An optimal agricultural land use and management are essential for the reduction in nutrient loads and improvement of water quality. In the Weiße Elster and Unstrut sub-basins (Elbe), an increase of 10% in the winter rape area can result in 12-19% more NO3-N load in rivers. In contrast, another energy plant, maize, has a moderate effect on the water environment. Mineral fertilizers have a much stronger effect on the NO3-N load than organic fertilizers. Cover crops, which play an important role in the reduction of nitrate losses from fields, should be maintained on cropland. The uncertainty in estimating future high flows and, in particular, extreme floods remain high due to different RCM structures, emission scenarios and multi-realizations. In contrast, the projection of low flows under warmer climate conditions appears to be more pronounced and consistent. The largest source of uncertainty related to NO3-N modelling originates from the input data on the agricultural management. / Wasserressourcen werden in Quantität und Qualität von Veränderungen in der Umwelt, insbesondere von Änderungen des Klimas und der Landnutzung, in signifikantem Maße beeinflusst. In dieser Arbeit wurden die Auswirkungen von Klimavariabilität und Klimawandel auf die Wasserressourcen und Extremereignisse wie Hoch- und Niedrigwasser in Deutschland untersucht. Die Analyse erfolgte auf der einen Seite modellgestützt, wobei die Ergebnisse aus verschiedenen regionalen Klimamodellen durch ein ökohydrologisches Modell in Änderungen in den hydrologischen Prozessen transformiert wurden, zum anderen aber auch datengestützt, z.B. durch die statistische Interpretation von beobachteten und simulierten Zeitreihen. Zusätzlich wurden die Auswirkungen von Landnutzungsänderungen auf Umsatz von Stickstoff in der Landschaft und im Wasser untersucht, wobei dasselbe ökohydrologische Modell zum Einsatz kam. Im Rahmen des Klimawandels wird zur Mitte dieses Jahrhunderts die aktuelle Evapotranspiration in den meisten Teilen Deutschlands mit großer Wahrscheinlichkeit zunehmen. Die täglichen Abflussmengen der fünf größten Flussgebiete in Deutschland (Ems, Weser, Elbe, Obere Donau und Rhein) werden dieser Untersuchung zur Folge im Sommer und Herbst um 8%-30% geringer sein als in der Referenzperiode (1961-1990). 80% der Szenariensimulationen stimmen darin überein, dass die 50-jährigen Niedrigwasserereignisse zum Ende dieses Jahrhunderts mit großer Wahrscheinlichkeit häufiger in den westlichen, den südlichen und den zentralen Teilen Deutschlands auftreten werden. Die gegenwärtige Niedrigwasserperiode (August-September) könnte sich zudem dann bis in den späten Herbst ausweiten. Für alle Flüsse werden höhere Winterabflüsse erwartet, wobei diese Zunahme für die Ems am stärksten ausfällt (ca. 18%). Mit größerer Unsicherheit sind dagegen die Aussagen zur Entwicklung der Hochwasser behaftet. Aus den Ergebnissen, die durch unterschiedliche regionale Klimamodelle und Szenarien getrieben wurden, kann jedoch kein allgemeingültiges Muster für die Änderungen der 50-jährigen Hochwässer ausgemacht werden. Eine optimierte Landnutzung und ein optimiertes Landmanagement sind für die Reduzierung der NO3-Einträge in die Oberflächengewässer essentiell. In den Einzusgebieten der Weißen Elster und der Unstrut (Elbe) kann eine Zunahme von 10% in der Anbaufläche von Winterraps zu einer 12-19% höheren NO3 Fracht führen. Mais, eine weitere Energiepflanze, hat hingegen einen mäßigeren Effekt auf die Oberflächengewässer. Die Höhe der Gabe von mineralischen Düngern beeinflußt zudem in starkem Maße die Nitratbelastung von Flüssen. Zwischenfrüchte können den NO3-Austrag im Sommer zusätzlich erheblich verringern. Insgesamt bleibt die Unsicherheit in der Vorhersage von Spitzenabflüssen und im Besonderen von Extrem-Hochwässern als Folge unterschiedlicher regionaler Klimamodelle, Emissionsszenarien und Realisationen sehr hoch. Im Gegensatz dazu erscheinen die Projektionen zu den Niedrigwasserereignissen unter wärmeren Bedingungen sehr viel deutlicher und einheitlicher. Die größte Unsicherheit in der Modellierung von NO3 dagegen sind die Eingangsdaten z.B. für das lokale landwirtschaftliche Management.

Based on a meta-study, the paper describes the existing options, areal extents, and Swedish farmers' conditions for energy crop production promoted by the governments to mitigate and adapt to climate change. The drivers of and barriers to cultivating various energy crops are described in terms of a variety of motivational factors. The approach used peer-reviewed and gray literature using three Internet sources. Questions addressed include the energy crops available to Swedish farmers and how well established they are in terms of areal extent. What drivers of and barriers to growing energy crops do farmers perceive? How do various motivational factors for these drivers and barriers correspond to the adoption of certain energy crops? The results indicate that 13 energy-related crops are available, of which straw (a residue), oil crops, and wheat are the most extensively produced in terms of cultivated area. Results confirm earlier research findings that converting from annual to perennial crops and from traditional crops or production systems to new ones are important barriers. Economic motivations for changing production systems are strong, but factors such as values (e.g., esthetic), knowledge (e.g., habits and knowledge of production methods), and legal conditions (e.g., cultivation licenses) are crucial for the change to energy crops. Finally, there are knowledge gaps in the literature as to why farmers decide to keep or change a production system. Since the Swedish government and the EU intend to encourage farmers to expand their energy crop production, this knowledge of such motivational factors should be enhanced. / Ett konkurrenskraftigt jordbruk – kommunikation kring klimatförändring och nya möjligheter (K3), Stiftelsen Lantbruksforskning

Although semi-natural grasslands in Europe are declining there is often a time delay in the local extinction of grassland species due to development of remnant populations, i.e., populations with an extended persistence despite a negative growth rate. The objectives of this study were to examine the occurrence of remnant populations after abandonment of semi-natural grasslands and to examine functional traits of plants associated with the development of remnant populations. We surveyed six managed semi-natural grasslands and 20 former semi-natural grasslands where management ceased 60-100 years ago, and assessed species response to abandonment, assuming a space-for-time substitution. The response of species was related to nine traits representing life cycle, clonality, leaf traits, seed dispersal and seed mass. Of the 67 species for which data allowed analysis, 44 species declined after grassland abandonment but still occurred at the sites, probably as remnant populations. Five traits were associated with the response to abandonment. The declining but still occurring species were characterized by high plant height, a perennial life form, possession of a perennial bud bank, high clonal ability, and lack of dispersal attributes promoting long-distance dispersal. Traits allowing plants to maintain populations by utilizing only a part of their life cycle, such as clonal propagation, are most important for the capacity to develop remnant populations and delay local extinction. A considerable fraction of the species inhabiting semi-natural grasslands maintain what is most likely remnant populations after more than 60 years of spontaneous succession from managed semi-natural grasslands to forest. / <p>authorCount :3</p>

Land deals are common in resource-rich countries and have increased during the past years. Contributing factors to the augmentation of land investments in agriculture and forestry are known to be climate change, rising global food prices, rising income levels and changing diets. The international debate on the topic points at the fact that these types of investments create not only great opportunities but also risks and challenges to the host countries, which often have high poverty rates. In order for land deals to be beneficial for all involved actors there is a voiced need for information about the performances and processes of large-scale land deals already at early stages. The objective of this study is to identify and understand the complexities at household level in relation to a new land deal and to explain how these complexities might hinder positive impacts on rural development that this land deal can entail. This thesis draws on a field study of one particular new land deal, Rainbow Oil, in Madagascar where the phenomenon has become substantial during the past few years. The material has been collected through semi-structured interviews and observations as part of an ethnographic approach. Interviews have been made with the investor and authorities at multiple levels but mainly with peasants in the concerned villages. The findings of the study have been analyzed using the sustainable livelihoods framework which permits the analysis to be both holistic and people-centered. Results from the study indicate that hopes for rural development due to the land deal of Rainbow Oil are evident but that certain factors in the peasants’ access to livelihood assets seem to hinder them from engaging in the land use change. Concluding remarks from the results of the study demonstrate that the investor might not have recognized the necessary prerequisites for a successful involvement of the local populations. Deficiencies in the communication between the actors seem to have created uncertainties and skepticism that can further impede both the development of the land use change itself and in turn also the possible development of particularly the concerned villages.

No description available.

<p>The Piedmont region of the southeastern United States has undergone considerable land-use change since settlement by Europeans and Africans. Forests were cleared for agriculture, followed centuries later by land abandonment. Following abandonment, natural recruitment, plantings for erosion control, and plantation forestry have resulted in a large area of the region covered by loblolly pine, Pinus taeda. Today, the Piedmont is a mosaic of farm fields, pastures, pine forests, and relic woodlots. The Calhoun Experimental Forest, located in Union County, SC, has provided a unique history of land use change's alteration of soil properties and processes, the ability of reforestation to restore or deplete soil fertility, and provided insights into the effects this change has on biological diversity.</p><p>In this work, the diversity of fungi living in soil is examined in the context of land-use change and soil biogeochemical change in and around the Calhoun Forest. This study uses molecular tools to identify fungal species from soil and to identify mycorrhizal associates of loblolly pine in a bioassay of propagule diversity, and proposes a novel use of quantitative PCR to quantify the relative abundance of major fungal families affected by land-use change.</p><p>Fungal diversity in soils is high in all land uses, but fungal communities shift from agricultural field communities largely comprised of unicellular ascomycetes and basal lineages to forest communities dominated by saprophytic and symbiotic basidiomycetes. In addition to this shift across a land use gradient, fungal communities are also responding to changes in carbon quantity and quality, biologically available nitrogen and phosphorus, pH, acidity and texture.</p><p>ECM propagule communities also differ across a land use gradient of cultivated fields, grasslands, pine forests, and mixed hardwood stands. There are few ECM propagules able to associate with loblolly pine in cultivated and grassland soils. There is a trend towards higher ECM diversity in the hardwood and pine soils, and both of those soil communities are distinct from each other as well as from soils from field treatments.</p><p>Quantitative PCR, coupled with a nested set of taxon-specific, fungal primers, is a potential way to estimate the abundance of the given taxon relative to all fungi in an environmental DNA. Primers specific to several taxonomic level of fungi were tested to confirm amplification in PCR, then were tested for taxonomic specificity by generating clone libraries with environmental DNA. Several of the successful primers were tested with soil DNA extracts in QPCR and the calculated ratios of fungal abundance varied widely by method of analysis. The results suggest that many repeated measurements and many replicates are required for a robust estimate of the relative abundance of a specific taxon.</p> / Dissertation

Environmental flows are important to maintain the ecological integrity of the estuary. In a watershed, it is influenced by land use land cover (LULC) change, climate variability, and water regulations. San Antonio, Texas, the 8th largest city in the US, is likely to affect environmental flows to the San Antonio Bay/Guadalupe Estuary, due to rapid urbanization. Time series analysis was conducted at several stream gauging stations to assess trends in hydrologic variables. A bootstrapping method was employed to estimate the critical value for global significance. Results suggested a greater number of trends are observed than are expected to occur by chance. Stream gauging stations present in lower half of the watershed experienced increasing trend, whereas upper half experienced decreasing trends. A similar spatial pattern was not observed for rainfall. Winter season observed maximum number of trends. Wavelet analysis on hydrologic variables, suggested presence of multi-scale temporal variability; dominant frequencies in 10 to 15 year scale was observed in some of the hydrologic variables, with a decadal cycle. Dominant frequencies were also observed in 17 to 23 year scale with repeatability in 20 to 30 years. It is therefore important to understand various ecological processes that are dominant in this scale and quantify possible linkages among them. Genetic algorithm (GA) was used for calibration of the Hydrologic Simulation Program in FORTRAN (HSPF) model. Although, GA is computationally demanding, it is better than manual calibration. Parameter values obtained for the calibrated model had physical representation and were well within the ranges suggested in the literature. Information from LANDSAT images for the years 1987, 1999, and 2003 were introduced to HSPF to quantify the impact of LULC change on environmental flows. Modeling studies indicated, with increase in impervious surface, peak flows increased over the years. Wavelet analysis pointed, that urbanization also impacted storage. Modeling studies quantified, on average about 50% of variability in freshwater inflows could be attributed to variation in precipitation, and approximately 10% of variation in freshwater inflows could be attributed to LULC change. This study will help ecologist, engineers, scientist, and politicians in policy making pertinent to water resources management.

The development of natural grass/scrubland for agricultural use within the Trans-Pecos basins has altered recharge mechanisms and raised questions about groundwater sustainability. Past efforts focused on recharge in arid basin systems used three main assumptions: there is minimal modern recharge, no widespread recharge on basin floors, and no recharge from anthropogenic sources. However, in the Trans-Pecos, nitrate (NO₃-) concentrations have increased in basin groundwater (up by 3-4 mg/l as NO₃- in 40 yrs), refuting the “classic” model and posing water quality risks. Grazing and irrigated agriculture have impacted basin hydrology by altering vegetation regime and the magnitude and spatial distribution of infiltration. This has increased recharge, Cl⁻, and mobile N flux to basin groundwater. A series of spatially-distributed net infiltration models were used to estimate potential recharge from natural and anthropogenic sources. Between 7-20% of potential recharge results from widespread recharge on the basin floors. Additionally, from 1960-2000, irrigation return flow may have contributed 3.0 × 10⁷ - 6.3 × 10⁷ m³ of recharge. These results are supported by field observations. Cores collected beneath agricultural land document changes in water content and pore water chemistry that imply increased downward flux of moisture and solute, and NO₃- and Cl- inventories beneath irrigated land are distinct in amount and profile from those in natural areas. There are significant implications for sustainability based upon the trends in groundwater NO₃- concentrations, core results, and net infiltration models: more recharge may enter the basins than previously estimated and there is a potential long-term concern for water quality. Due to thick unsaturated zones in the basins, long travel times are anticipated. It is unknown if NO3- and Cl⁻ flux has peaked or if effects will continue for years to come. Further study should be undertaken to examine anthropogenic impacts on basin water quality. Additionally, these impacts may occur in similar systems globally and there is considerable evidence for the re-evaluation of the validity of the “classic” model of recharge in arid basin systems. Future studies and management plans should incorporate potential impacts of changes in vegetation and land use on recharge processes and water budgets in arid basins. / text

Species distribution models must balance the need for model generality with that for precision and accuracy. This is critical when modelling range-expanding species such as invasive species. Given the increased use of species distribution models to study invasive species-landscape relationships, a better understanding of the effect of spatial scales, sampling biases, model transferability and discrepancies between different models’ future predictions is necessary. This dissertation addresses these knowledge gaps using mute swans (Cygnus olor) as a case study species. I specifically examine mute swan’s distributions in parts of their native range of Britain and their non-native range of Ontario, Canada. I first investigate which environmental variables at which spatial scales best explain mute swan’s distribution in its non-native range. Second, I perform a sample selection bias study to examine predictive accuracy when species distribution models are built using varying ranges of environmental variables and applied to broader spatial extents. Third, I examine the potential for, and limitations of model transferability between native and non-native regions. Finally, I use two different modelling approaches and three different climate change and land use change scenarios to predict future mute swan habitat suitability. The results indicate that (1) models with better predictive accuracy include environmental variables from multiple ecologically-meaningful scales and measured at spatial extents that include a broad range of environmental variable values; (2) models can exhibit asymmetrical transferability; (3) climate change will facilitate mute swan range expansion in the future more than land use change; and (4) mute swans are often found near urban waterbodies. When modelling invasive species distributions, I suggest that ecologists consider: (I) spatial scale of the underlying landscape processes and species’ use of the landscape; (II) variability and range of each environmental variable used for building models; and (III) stage of establishment of the invasive species.