Changes In Land Use Management Research Articles

The Labile and Resistant Soil Organic Carbon Pools in the North America Great Plains

Among the three major global carbon cycle components, the terrestrial one has been the most uncertain because of the complexity of the soil organic carbon (SOC) dynamics. Previous tracer studies, however, have shown that SOC consists of labile and resistant pools. Labile pools turn over in decades, and resistant pools turn over in hundreds or thousands of years. Labile pools are active in carbon and nutrient cycles and responsive to land-use management changes, whereas resistant pools are less so. Very few studies have actually quantified labile and resistant SOC pools because the isotopic tracer methods, such as the paired-plot bulk-carbon (PPBC) method, can only be applied to a few special cases. I found a study of SOC in the North America Great Plains, in which some of the data are suitable for the PPBC method. The results revealed that the turnover times of the labile SOC pools ranged from 17 years to 93 years, and the sizes ranged from 1.2 g kg−1 to 17.6 g kg−1. The turnover times of the resistant pools ranged from 899 years to 5138 years, and the sizes ranged from 5.0 g kg−1 to 12.4 g kg−1. Land management practices changed the sizes of the labile pools but not their turnover times. This study also pointed out a possibility that allows the application of the PPBC method to a set of much broader cases.

Extinction risks and mitigation for a megaherbivore, the giraffe, in a human-influenced landscape under climate change.

Megaherbivores play "outsized" roles in ecosystem functioning but are vulnerable to human impacts such as overhunting, land-use changes, and climate extremes. However, such impacts-and combinations of these impacts-on population dynamics are rarely examined using empirical data. To guide effective conservation actions under increasing global-change pressures, we developed a socially structured individual-based model (IBM) using long-term demographic data from female giraffes (Giraffa camelopardalis) in a human-influenced landscape in northern Tanzania, the Tarangire Ecosystem. This unfenced system includes savanna habitats with a wide gradient of anthropogenic pressures, from national parks, a wildlife ranch and community conservation areas, to unprotected village lands. We then simulated and projected over 50 years how realistic environmental and land-use management changes might affect this metapopulation of female giraffes. Scenarios included: (1) anthropogenic land-use changes including roads and agricultural/urban expansion; (2) reduction or improvement in wildlife law enforcement measures; (3) changes in populations of natural predators and migratory alternative prey; and (4) increases in rainfall as predicted for East Africa. The factor causing the greatest risk of rapid declines in female giraffe abundance in our simulations was a reduction in law enforcement leading to more poaching. Other threats decreased abundances of giraffes, but improving law enforcement in both of the study area's protected areas mitigated these impacts: a 0.01 increase in giraffe survival probability from improved law enforcement mitigated a 25% rise in heavy rainfall events by increasing abundance 19%, and mitigated the expansion of towns and blockage of dispersal movements by increasing abundance 22%. Our IBM enabled us to further quantify fine-scale abundance changes among female giraffe social communities, revealing potential source-sink interactions within the metapopulation. This flexible methodology can be adapted to test additional ecological questions in this landscape, or to model populations of giraffes or other species in different ecosystems.

Health-economic valuation of lowering nitrate standards in drinking water related to colorectal cancer in Denmark

Nitrate in drinking water is a contaminant which can affect human health and has been associated with an increased risk of, amongst other diseases, colorectal cancer. Based on epidemiologic data from Denmark on the association between drinking water nitrate and colorectal cancer, the health and economic consequences of lowering the standard of nitrate in drinking water from 50 mg/L to 9.25 mg/L and 3.87 mg/L, respectively are analyzed. The drinking water nitrate attributable number of cases was estimated using the risk in the exposed and unexposed population based on current nationwide exposure distributions. The analysis shows that a lower limit of 9.25 mg/L would decrease the annual number of colorectal cancer cases by 72 (95 % confidence interval: 34–114) and by an additional 55 (95 % CI: 10–100) for a stricter limit of 3.87 mg/L. The resulting avoided health-related costs are $179 million per year for the 9.25 mg/L nitrate limit and another $138 million per year for a further reduction to 3.87 mg/L nitrate. The new requirements would incur costs linked to either i) changes in land use management, ii) well reallocation or iii) use of treatment technologies. The additional costs are estimated to $0.03–1.84 per m3 abstracted water from public water companies, which together with costs for owners of private wells, will result in an average additional cost of $9 and $6 million per year for the two levels. The economic health benefits are higher than the costs for both limits with net gains of $170 million (9.25 mg/L) and additionally $132 million (3.87 mg/L) a year. Even in a worst-case scenario (lowest health-related benefits and highest mitigation costs), there is a likely economic gain for society from lowering the limit to 9.25 mg/L, but this might not be the case for the lower limit of 3.87 mg/L.

Epigeal fauna and edaphic properties as possible soil quality indicators in forest restoration areas in Espírito Santo, Brazil

The study of soil quality indicators can indicate the efficiency of forest restoration practices. Litter, soil chemical attributes, and soil fauna can be used for this purpose since these factors are linked to each other in nutrient cycling and respond to changes in land use management. The present study aimed to identify accumulated litter biomass on topsoil, its nutrient concentration, composition of the epigeal fauna community, and topsoil chemical attributes as possible soil quality indicators in restoration areas of Atlantic Forest (T1, T2, and T3) with different levels of native tree seedlings richness (29, 58, and 114 species, respectively), pasture (T4), and native forest (T5, control), by three plots (50 × 50 m) in each area, in the municipality of Linhares, Espírito Santo, Brazil. Samples of accumulated litter on topsoil, topsoil (0–5 cm), and community of epigeal fauna (by pitfall traps) were collected during the dry and rainy seasons. Accumulated litter biomass on the topsoil, concentration of K and Mg in its biomass, abundance of Coleoptera and Pseudoscorpionida, total N and exchangeable K concentrations in the topsoil were the most relevant soil quality indicators, according to the principal component analysis. In both climatic seasons, T5 presented high dissimilarity in relation to the other areas and best soil quality due to its association to higher values of accumulated litter biomass, its nutrient concentration (N, K, Ca, Mg, S), relative frequency or abundance of Coleoptera, Pseudoscorpionida, and Others, concentrations of total organic carbon, total N, available P, exchangeable Ca, extractable acidity, sum of bases, and cation exchange capacity; T1, T2, and T3 were associated to higher values of relative frequency of Formicidae and presented low dissimilarity to each other; T4 was associated to higher values of pH. Therefore, the forest restoration areas have not yet contributed to the general quality of the soil approaching that observed in T5.

Late Holocene environmental change and anthropogenic: Ecosystem interaction on the Laikipia Plateau, Kenya

East African ecosystems have been shaped by long-term socio-ecological–environmental interactions. Although much previous work on human–environment interrelationships have emphasised the negative impacts of human interventions, a growing body of work shows that there have also often been strong beneficial connections between people and ecosystems, especially in savanna environments. However, limited information and understanding of past interactions between humans and ecosystems of periods longer than a century hampers effective management of contemporary environments. Here, we present a late Holocene study of pollen, fern spore, fungal spore, and charcoal analyses from radiocarbon-dated sediment sequences and assess this record against archaeological and historical data to describe socio-ecological changes on the Laikipia Plateau in Rift Valley Province, Kenya. The results suggest a landscape characterised by closed forests between 2268 years before present (cal year BP) and 1615 cal year BP when there was a significant change to a more open woodland/grassland mosaic that continues to prevail across the study area. Increased amounts of charcoal in the sediment are observed for this same period, becoming particularly common from around 900 cal year BP associated with fungal spores commonly linked to the presence of herbivores. It is likely these trends reflect changes in land use management as pastoral populations improved and extended pasture, using fire to eradicate disease-prone habitats. Implications for contemporary land use management are discussed in the light of these findings.

Half of global methane emissions come from highly variable aquatic ecosystem sources

Atmospheric methane is a potent greenhouse gas that plays a major role in controlling the Earth’s climate. The causes of the renewed increase of methane concentration since 2007 are uncertain given the multiple sources and complex biogeochemistry. Here, we present a metadata analysis of methane fluxes from all major natural, impacted and human-made aquatic ecosystems. Our revised bottom-up global aquatic methane emissions combine diffusive, ebullitive and/or plant-mediated fluxes from 15 aquatic ecosystems. We emphasize the high variability of methane fluxes within and between aquatic ecosystems and a positively skewed distribution of empirical data, making global estimates sensitive to statistical assumptions and sampling design. We find aquatic ecosystems contribute (median) 41% or (mean) 53% of total global methane emissions from anthropogenic and natural sources. We show that methane emissions increase from natural to impacted aquatic ecosystems and from coastal to freshwater ecosystems. We argue that aquatic emissions will probably increase due to urbanization, eutrophication and positive climate feedbacks and suggest changes in land-use management as potential mitigation strategies to reduce aquatic methane emissions.

Impact of recent vegetation greening on temperature and precipitation over China

Changes in land-use management and natural climate variability has led to significant vegetation greening in China over the past decades, as evidenced by satellite observations. In this study, we used a high-resolution land-atmosphere coupled regional climate model to assess the impacts of recent greening on China's regional summer climate. Our results inferred a country-averged surface cooling of 0.11 °C and a precipitation increase of 0.02 mm/d during summer in response to China's widespread greening. We also identified significant regional variability in the climatic responses to vegetation change. The regions of northern China showed significant cooling, including the Northeast China Plain, Loess Plateau, and the eastern areas of the Northern arid and semi-arid region; however, no significant temperature changes were simulated in southern China. Summer precipitation decreased in southern China and increased in the Huang-Huai-Hai Plain and the northern Loess Plateau. Variations in moisture flux convergence had a stronger influence on the precipitation patterns relative to evapotranspiration. Furthermore, our results suggested that vegetation greening would influence the occurrence of extreme climate events by decreasing the number of heatwave days (by 1–3 days, particularly in northern China), reducing the number of continuous drought events in northern China, and minimizing the risks of floods in southern China.

Stochastic assessment of the effect of land-use change on nonpoint source-driven groundwater quality using an efficient scaling approach

Assessing the impact of a land-use change (LUC) or change in land-use management on nonpoint source-driven groundwater quality in heterogeneous aquifers requires complex analysis. Stochastic methods have been used to account for prediction uncertainty but at high computational cost, which significantly limits the application of these approaches. As an efficient alternative, this study evaluates the application of a meta-analytical solution for evaluating the change in contaminant breakthrough curves at extraction wells in response to LUC. The solution uses the concentration percentiles from a reference stochastic simulation of water flow and solute transport in a groundwater system, assuming a reference land-use distribution pattern. Reference land-use controls the spatially variable rates of both, recharge and contaminant mass loading. The effect of a LUC is evaluated by scaling the ratio between the reference and the new (post-LUC) average input concentrations. The validity of the proposed meta-analysis tool is tested by comparing the results of the meta-analytical solution with those from a full stochastic simulation of the post-LUC scenario. Simulation results show that the accuracy of the meta-analytical solution is best when the regional average recharge rates for both pre- and post-LUC remain approximately unchanged, for any change in contaminant mass loading. Results also indicate that changes in spatial variability and pattern of the recharge rate do not significantly impact the flow field, travel times, and resulting concentrations, if the magnitude of local recharge remains about the same. Lastly, the results show large variability among wells of (and—for an individual well—uncertainty about) the time lag between the time of LUC and the time of consequential effective change in concentrations across wells in the affected region, captured here using statistical metrics.

Mining activity impacts on soil erodibility and reservoirs silting: Evaluation of mining decommissioning strategies

This study focuses on the nexus between coal mining and water storage, analyzing the strategies to reduce the negative effects of exhausted/abandoned mining sites on catchments where water reservoirs are located.Sediment management represent a key point to promote sustainable water resources development and it is strictly connected with the proper management of land use change, especially in the areas devoted to mining activities. The presence of a reservoir represents a major challenge because these structures are threatened by the rapid loss of storage volume due to excessive sedimentation.The case of San Cipriano reservoir in central Italy represents an ideal set to explore the effects of mining on water storage because it is located at the outlet of a catchment strongly influenced by one of the most important lignite mine in central Italy. The Soil Water Assessment Tool (SWAT) is used to evaluate different scenarios of mine decommissioning, aiming at supporting the identification of the best strategies to avoid reservoir sedimentation. Two scenarios of environmental restoration of the mining area are evaluated. In the first case, the ongoing reforestation with native plants like oaks and deciduous trees is analyzed. In the second scenario the authors focus on the evaluation of a wider landscape restoration project (including reforestation and river bodies rehabilitation) recently drafted by local institutions.The results provide a quantitative evaluation of the effectiveness of the proposed strategies in reducing the impacts of existing mining sites from a hydrological perspective. In particular, the analyzed scenarios show that afforestation and river restoration lead to a strong reduction of sediment yield while downward trend occurred for water yield.

Spiders (Arachnida: Araneae) in Agricultural Land Use Systems in Subtropical Environments

ABSTRACT Changes in land use management in agricultural areas can affect the biodiversity of spider families. This study aimed to evaluate spider diversity in different land use systems with capture by two sampling methods, and to identify soil properties that can modulate the occurrence of spiders. Five land use systems, representative of traditional agricultural areas, were evaluated in the west of Santa Catarina, Brazil, to establish a scale of land use intensity: native forest, eucalyptus reforestation areas, pastures, crop-livestock integration [...]

The effects of land management (grazing intensity) vs. the effects of topography, soil properties, vegetation type, and climate on soil carbon concentration in Southern Patagonia

Grazing is an economically important activity in Southern Patagonia’s steppe and woodland ecosystems. In the past, emphasis has been on maximizing the provisioning capacity of these ecosystems with little concern for the longer term conservation of the ecosystem services related to climate regulation, like carbon sequestration. This is changing rapidly as livestock producers in the region work to develop a certification scheme for sustainable land management for Patagonians rangelands. This study is a scientific contribution towards this broader social objective in which we test whether soil C concentration in topsoil (10 cm depth) can be used as an indicator of rangeland condition. Data on climate, soil chemistry, topography, ecosystem type and stocking rates were obtained from the PEBANPA network of permanent plots database for 145 sites across Southern Patagonia. These variables were used as independent variables in a partial least squares regression in which top soil C was the dependent variable. The effects of land use (stocking rate) on top soil C were barely detectable at the regional scale in Patagonia. Top soil C was however strongly associated with other independent variables, notably soil chemistry and climate variables and also vegetation type. Thus, changes in land use management may not have a significant impact on soil carbon sequestration in these types of ecosystems. This may be because many factors interact to determine top soil C such that the footprint of overgrazing on top soil C is drowned out at the regional scale by other variables. This highlights the need for further work to develop indicators for sustainable land management in the region.

A Review of the Application of Optical and Radar Remote Sensing Data Fusion to Land Use Mapping and Monitoring

The wealth of complementary data available from remote sensing missions can hugely aid efforts towards accurately determining land use and quantifying subtle changes in land use management or intensity. This study reviewed 112 studies on fusing optical and radar data, which offer unique spectral and structural information, for land cover and use assessments. Contrary to our expectations, only 50 studies specifically addressed land use, and five assessed land use changes, while the majority addressed land cover. The advantages of fusion for land use analysis were assessed in 32 studies, and a large majority (28 studies) concluded that fusion improved results compared to using single data sources. Study sites were small, frequently 300–3000 km 2 or individual plots, with a lack of comparison of results and accuracies across sites. Although a variety of fusion techniques were used, pre-classification fusion followed by pixel-level inputs in traditional classification algorithms (e.g., Gaussian maximum likelihood classification) was common, but often without a concrete rationale on the applicability of the method to the land use theme being studied. Progress in this field of research requires the development of robust techniques of fusion to map the intricacies of land uses and changes therein and systematic procedures to assess the benefits of fusion over larger spatial scales.

Microbial and enzymes response to nutrient additions in soils of Mt. Kilimanjaro region depending on land use

Microbial and enzyme activities can be used to identify and assess the impacts of changes in land use management on soil quality. However, only few studies have investigated the effects of land use and nutrient additions on enzyme activities and microbial processes in tropical African soils. Glucose and nutrients (N and P) were added to soils (0–20 cm) from natural and agricultural ecosystems: (1) savannah, (2) maize fields, (3) lower montane forest, (4) coffee plantation, (5) grasslands (6) Chagga homegardens common at Mt. Kilimanjaro region and East Africa. Microbial biomass and activities of β-glucosidase, cellobiohydrolase, chitinase and phosphatase were monitored over 60 days incubation period. Microbial biomass content and enzyme activities were generally higher in soils under natural vegetation compared to corresponding agricultural soils. Decline in microbial biomass C content over time was higher in natural ecosystems compared to agricultural soils. However, the microbial biomass C content in Chagga homegarden soils was relatively stable. Land use was negatively correlated to β-glucosidase, cellobiohydrolase and chitinase activity, but positively correlated to phosphatase activity. β-glucosidase and cellobiohydrolase, involved in the C-cycle, were the most sensitive to landuse change. Chitinase activity was 2–6 times higher in soils under natural vegetation compared to corresponding arable soils. Phosphatase displayed very high activities in all land use types. This is attributed to the high P retention capacity common for andic soils similar to those occurring at Mt. Kilimanjaro region. Increased P availability stimulated enzyme activities in lower montane forest and Chagga homegarden soils. Overall, microbial biomass and enzyme activities showed a strong decrease with increased land use intensity and should therefore be taken into consideration in monitoring and assessing the impact of land use change at Mt. Kilimanjaro region.

Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

Abstract. This study reports the use of high-resolution water quality monitoring to assess the influence of changes in land use management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the issue of agricultural soil P management and subsequent diffuse transfers at high river flows over a 5-year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STSs) and mitigation efforts – a key concern for catchment management. Results showed an inconsistent response to soil P management over 5 years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STSs) and also to gauge their effectiveness.

Land-use zoning in fast developing coastal area with ACO model for scenario decision-making

Potential ecological environment risks have been emerged as the result of land-use change (e.g. urbanization) in coastal areas. Conflicts between urban growth and ecological conservation should be brought to the forefront especially in the fast developing coastal areas. An optimized landscape pattern for land-use planning could reduce the risk at the regional scale. The cell-based allocation of different land use into the geospace (i.e. land-use spatial zoning, LUSZ) to form optimal pattern with planning objectives and constrains could be viewed as a spatial optimization problem. This study aims to develop a framework incorporated with ant colony algorithm optimization (ACO) to solve LUSZ problem based on the planning guideline of China. Three planning scenarios (i.e. development focusing on urban growth, development considering ecological conversion, and coordinative development between growth and protection) were devised and analyzed with the study area of Doumen District. Comparative analysis with landscape metrics and suitability evaluation indicates that scenario of coordinative development is more available and plausible for land-use change management. This study provides a quantitative and feasible procedure to achieve optimal development pattern on given planning objectives. Moreover, it also demonstrates that cell-based spatial optimization model can generate optimal planning scenarios for decision-making.

From coping to adaptation to economic and institutional change – Trajectories of change in land-use management and social organization in a Biosphere Reserve community, Mexico

Smallholder farming communities are increasingly affected by local impacts of international market dynamics, and (inter)governmental economic and nature conservation policies to which they respond through coping or adaptation. Although the attributes that underpin the capacity to adapt are widely agreed upon in literature, empirical evidence on how rural communities can develop adaptations are still scarce. Here, we provide such evidence based on a comprehensive driver-response reconstruction of a community in the buffer-zone of a Biosphere Reserve in Chiapas, Mexico. We found that coping (between 1990 and 2000) was gradually replaced by adaptations (1995–2010) based on: (i) diversification of land-use, (ii) improved social organization, (iii) improved communal decision-making, and (iv) more sustainable forms of land management. The diversification of local farming systems through inclusion of organic forest-based palm and coffee cultivation and the establishment of associated organizations, formed the basis of these changes. These adaptations were mainly supported by improved social, institutional and political capital. Communal forest resources, long-term support of an NGO and a highly motivated population, were essential circumstances that allowed these trajectories to develop. However, current unequal land and power distribution could undermine and debilitate adaptive capacity. Communities and supportive organizations need to be aware and capable to adjust continuously to prevent today's adaptation strategies from becoming tomorrow's coping responses.

Measurement of flood peak effects as a result of soil and land management, with focus on experimental issues and scale

As a result of several serious flood events which have occurred since 2000, flooding across Europe is now receiving considerable public and media attention. The impact of land use on hydrology and flood response is significantly under-researched, and the links between land use change and flooding are still unclear. This study considers runoff data available from studies of arable in-field land use management options, applied with the aim of reducing diffuse pollution from arable land, in order to investigate whether these treatments also have potential to reduce downstream flooding. Intensive monitoring of 17 hillslope treatment areas produced a record of flood peak data covering different mitigation treatments for runoff which occurred in the winter of 2007–2008. We investigated event total runoff responses to rainfall, peak runoff, and timing of the runoff peaks from replicates of different treatments, in order to assess whether there is a significant difference in flood peak response between different mitigation options which could be used to mitigate downstream flood risk. A mixed-modelling approach was adopted in order to determine whether differences observed in runoff response were significant. The results of this study suggest that changes in land use management using arable in-field mitigation treatments can affect local-scale runoff generation, with differences observed in the size, duration and timing of flood peaks as a result of different management practices, but the study was unable to allow significant treatment effects to be determined. We suggest that further field studies of the effects of changes in land use and land use management need to upscale towards farm and catchment scale experiments which consider high quality before-and-after data over longer temporal timescales. This type of data collection is essential in order to allow appropriate land use management decisions to be made.

Plant carbon substrate supply regulated soil nitrogen dynamics in a tallgrass prairie in the Great Plains, USA: results of a clipping and shading experiment

Aims Land use management affects plant carbon (C) supply and soil environments and hence alters soil nitrogen (N) dynamics, with consequent feedbacks to terrestrial ecosystem productivity. The objective of this study was to better identify mechanisms by which land-use management (clipping and shading) regulates soil N in a tallgrass prairie, OK, USA. Methods We conducted 1-year clipping and shading experiment to investigate the effects of changes in land-use management (soil microclimates, plant C substrate supply and microbial activity) on soil inorganic N (NH + � N and NO � � N), net N mineralization and nitrification in

Trophic assessment of streams in Uruguay: A Trophic State Index for Benthic Invertebrates (TSI-BI)

Human activities are radically changing natural land cover and increasing the delivery of soil, organic compounds, nutrients, toxic agrochemicals and other contaminants to aquatic ecosystems. The eutrophication of streams, rivers, lakes, reservoirs and costal zones is one of the most important consequences of human activities. In this study we assessed the trophic status of 28 wadeable stream reaches of the Santa Lucía basin, an important economic region of Uruguay. We developed a Trophic State Index of Benthic Invertebrates (TSI-BI), the first of its kind for South American lotic systems. The methodological approach consisted of determining the ambient trophic gradient via canonical correspondence analysis based on the benthic invertebrate abundance matrix and an environmental variable matrix. The rescaled site scores served as environmental variables in the weighted averaging model (WA), to weight the benthic abundances and then find the optimum and tolerance of each of the sampled genus. These data were used to estimate the TSI-BI scores. These scores, in conjunction with the total phosphorus concentrations (TP), were used to group the study reaches when running a cluster analysis. The basic statistical parameters of the defined groups serve as an input to identify the threshold values of TP and TSI-BI corresponding with the different trophic states. The boundaries of TSI-BI and TP demarcating mesotrophic and eutrophic states were 8 and 71 μg/l, respectively, and can be considered the limits between impaired and less altered reaches. The results also indicated that the trophic status of the reaches is related to land use intensity. A change in land use management seems to be critical for the preservation of one of the most important water supply systems in Uruguay.

An Analysis of Land Use Change in Urban Boroler Areas of Shijiazhuang City

The urban border area is consistently in a dynamic change,and the management of land use change in such an area is the key to coordinating urbanization with farmland protection.Based on the method of comparison after classification and taking different time-based high-resolution remote sensing images as information sources,the authors extracted land change information of 1994-2002 from the urban border areas of Shijiazhuang City.Based on an analysis of urban border land use change,the authors put forward some proposals on the improvement of the urban border land-use management in Shijiazhuang City in future.