Impact Of Land Use Management Research Articles

Investigating the impact of land use management on terrestrial carbon emissions in Nanjing city: past trajectories and multi-scenario simulation prediction

Investigating the impact of land use management on terrestrial carbon emissions in Nanjing city: past trajectories and multi-scenario simulation prediction

Soil carbon dynamics in the temperate Himalayas: Impact of land use management

Food security and environmental health are directly linked with soil carbon (C). Soil C plays a crucial role in securing food and livelihood security for the Himalayan population besides maintaining the ecological balance in the Indian Himalayas. However, soil C is being severely depleted due to anthropogenic activities. It is well known that land use management strongly impacted the soil organic carbon (SOC) dynamics and also regulates the atmospheric C chemistry. Different types of cultivation practices, i.e., forest, plantations, and crops in the Kashmir Himalayas, India, has different abilities to conserve SOC and emit C in the form of carbon dioxide (CO2). Hence, five prominent land use systems (LUC) (e.g., natural forest, natural grassland, maize-field-converted from the forest, plantation, and paddy crop) of Kashmir Himalaya were evaluated to conserve SOC, reduce C emissions, improve soil properties and develop understanding SOC pools and its fractions variations under different land use management practices. The results revealed that at 0–20 cm and 20–40 cm profile, the soil under natural forest conserved the highest total organic carbon (TOC, 24.24 g kg−1 and 18.76 g kg−1), Walkley-black carbon (WBC, 18.23 g kg−1 and 14.10 g kg−1), very-labile-carbon (VLC, 8.65 g kg−1, and 6.30 g kg−1), labile-carbon (LC, 3.58 g kg−1 and 3.14 g kg−1), less-labile-carbon (VLC, 2.59 g kg−1, and 2.00 g kg−1), non-labile-carbon (NLC, 3.41 g kg−1 and 2.66 g kg-1), TOC stock (45.88 Mg ha−1 and 41.16 Mg ha−1), WBC stock (34.50 Mg ha−1 and 30.94 Mg ha−1), active carbon pools (AC, 23.14 Mg ha−1 and 20.66 Mg ha−1), passive carbon pools (PC, 11.40 Mg ha−1 and 10.26 Mg ha−1) and carbon management index (CMI, 100), followed by the natural grassland. However, the lowest C storage was reported in paddy cropland. The soils under natural forest and natural grassland systems had a greater amount of VLC, LC, LLC, and NLC fraction than other land uses at both depths. On the other hand, maize-field-converted-from-forest-land-use soils had a higher proportion of NLC fraction than paddy soils; nonetheless, the NLC pool was maximum in natural forest soil. LUS based on forest crops maintains more SOC, while agricultural crops, such as paddy and maize, tend to emit more C in the Himalayan region. Therefore, research findings suggest that SOC under the Kashmir Himalayas can be protected by adopting suitable LUS, namely forest soil protection, and by placing some areas under plantations. The areas under the rice and maize fields emit more CO2, hence, there is a need to adopt the conservation effective measure to conserve the SOC without compromising farm productivity.

Modelling the impact of land use management on water resources in a tropical inland valley catchment of central Uganda, East Africa

A combination of climate change, food demand, population growth, and other driving forces are causing land use and land cover change (LULC) in wetlands of Sub Saharan Africa (SSA). This has a profound effect on water resources, thus it is imperative that such consequences arising from these changes are predicted accurately to support land use management. For that, local scale studies are required to understand the system and to perform scenario analysis. The focus of this study was on small scale inland valleys which are common in SSA. The impact of LULC on the hydrological processes in a tropical inland valley was investigated. A hydrological response unit (HRU)-based (ArcSWAT2012) and a grid-based setup (SWATgrid) of the Soil Water Assessment Tool (SWAT) model are applied. Good model performance was achieved after calibration and validation with daily discharge (R2 and NSE > 0.7 for both model setups). Annual water balance indicates that 849.5 mm representing 65% of precipitation is lost via evapotranspiration. Surface runoff (77.9 mm) and lateral flow (86.5 mm) are the highest contributors to stream flow in the inland valley. Four land use management options are developed in addition to the current land use system, with different water resources conservation levels (Conservation, Slope conservation, Protection of headwater catchment, and Exploitation). There is a strong relationship between the first three management options with decreasing surface runoff, annual discharge and water yield while the fourth option will increase annual discharge and total water yield. This suggests that if poor management and increasing exploitation of the inland valleys persist, the availability of water resources for human consumption and plant growth will decrease. This study contributes to improving the scientific knowledge on the impact of land use change on hydrological processes in the catchment-wetland nexus to support sustainable water resources management.

Impacts of land-use management on ecosystem services and biodiversity: an agent-based modelling approach.

The science of ecosystem service (ES) mapping has become increasingly sophisticated over the past 20 years, and examples of successfully integrating ES into management decisions at national and sub-national scales have begun to emerge. However, increasing model sophistication and accuracy—and therefore complexity—may trade-off with ease of use and applicability to real-world decision-making contexts, so it is vital to incorporate the lessons learned from implementation efforts into new model development. Using successful implementation efforts for guidance, we developed an integrated ES modelling system to quantify several ecosystem services: forest timber production and carbon storage, water purification, pollination, and biodiversity. The system is designed to facilitate uptake of ES information into land-use decisions through three principal considerations: (1) using relatively straightforward models that can be readily deployed and interpreted without specialized expertise; (2) using an agent-based modelling framework to enable the incorporation of human decision-making directly within the model; and (3) integration among all ES models to simultaneously demonstrate the effects of a single land-use decision on multiple ES. We present an implementation of the model for a major watershed in Alberta, Canada, and highlight the system’s capabilities to assess a suite of ES under future management decisions, including forestry activities under two alternative timber harvest strategies, and through a scenario modelling analysis exploring different intensities of hypothetical agricultural expansion. By using a modular approach, the modelling system can be readily expanded to evaluate additional ecosystem services or management questions of interest in order to guide land-use decisions to achieve socioeconomic and environmental objectives.

Impact of Land Use Management and Soil Properties on Denitrifier Communities of Namibian Savannas.

We studied potential denitrification activity and the underlying denitrifier communities in soils from a semiarid savanna ecosystem of the Kavango region in NE Namibia to help in predicting future changes in N(2)O emissions due to continuing changes of land use in this region. Soil type and land use (pristine, fallow, and cultivated soils) influenced physicochemical characteristics of the soils that are relevant to denitrification activity and N(2)O fluxes from soils and affected potential denitrification activity. Potential denitrification activity was assessed by using the denitrifier enzyme activity (DEA) assay as a proxy for denitrification activity in the soil. Soil type and land use influenced C and N contents of the soils. Pristine soils that had never been cultivated had a particularly high C content. Cultivation reduced soil C content and the abundance of denitrifiers and changed the composition of the denitrifier communities. DEA was strongly and positively correlated with soil C content and was higher in pristine than in fallow or recently cultivated soils. Soil type and the composition of both the nirK- and nirS-type denitrifier communities also influenced DEA. In contrast, other soil characteristics like N content, C:N ratio, and pH did not predict DEA. These findings suggest that due to greater availability of soil organic matter, and hence a more effective N cycling, the natural semiarid grasslands emit more N(2)O than managed lands in Namibia.

A comparative study of the effect of imdacloprid and dimethoate on soil enzyme

Soil metabolism seems to be one of the major tools to study the effect of agrochemicals (pesticides and fertilizers) on soil health. It is an appropriate indicator for highlighting the impact of land use management, soil quality monitoring and pollution. Several experiments were conducted to find out the effect of pesticides on soil metabolism. However few studies were conducted on Imidacloprid (neonicotinoid) and Dimethoate (organophosphate) which showed no concrete conclusion. So an attempt was undertaken to find out the toxicity of Imidacloprid and Dimethoate which are being used mostly in the Indian crop fields today due to its less toxicity. The study found an increase of dehydrogenase activity by 15.36% in recommended agricultural dose of imidacloprid treated soil and decreased by 36.25% in dimethoate treated soil after 15 days. The acid phosphatase activity was also increased by 24.37% in imidacloprid treated soil and decreased by 23.65% in dimethoate treated soil till 15 days. Similar trend was also found in alkaline phosphatase activity where there is an increase of 22.87% in imidacloprid treated soil and decreased by 31.77% in dimethoate treated soil. But the urease activity was less in soil treated with recommended agricultural doses of imidacloprid and dimethoate as compared to control soil. The present study indicates greater toxicity of dimethoate in comparison to Imidacloprid. So it is suggested to avoid dimethoate even at the recommended doses.

Impact of land-use management on nitrogen transformation in a mountain forest ecosystem in the north of Iran

Soil inorganic N is one of the most important soil quality indexes, which may be influenced by land-use change. The historical conversion of land-use from native vegetation to agriculture resulted in sharp declines in soil N dynamics. This study was conducted to determine the soil inorganic N concentrations and net N mineralization rate in four common types of land-uses in the mountain forest area in the north of Iran, namely arable land, pine plantation, ash plantation, and beech stand. The soil samples were taken from top mineral soil layer (5 cm) in each site randomly (n=6) during August- September 2010. Beech stand and ash plantation showed significantly higher total nitrogen compared with arable land and pine plantation, while extractable NH4+-N concentration was significantly greater in Beech stand compare to arable soils (p<0.05). No significantly difference was found in Net N mineralization, net nitrification and net ammonification rates among different land-uses. Results showed that net N mineralization and ammonification were occurred just in the soil of Ash plantation during the incubation time. Our findings suggested that conversion of Hyrcanian forests areas to pine plantation and agricultural land can disrupt soil natural activities and affect extremely soil quality.

Impacts of Land-use Management on Small Mammals in the Adirondack Park, New York

We examined the response of small-mammal communities to human disturbance along a gradient from wilderness to managed forest to rural residential development in the Adirondack Park of northern New York. Our objectives were to determine if small-mammal community composition and structure differed among sites along a gradient of human impact and to relate changes in small-mammal community composition to habitat changes along the gradient. We sampled small mammals with track tubes on 10 replicates each of old growth, managed forest, and areas of residential development in the central Adirondacks. We estimated differ- ences in species composition, abundance, diversity, evenness, and community structure, and identified habitat variables associated with differences in these mea- sures. We used canonical correspondence analysis (CCA) to examine the relationship between patterns in small-mammal community composition and sampled habitat variables. Some small-mammal species demonstrated a numerical response to increasing human impact on the landscape, with abundance of total small mammals, eastern chipmunk, and Sorex species highest in old growth and declining in managed forests and areas of residential development. Differences among man- agement types were reflected more strongly in total abundance and community structure than through indices of richness and diversity, which did not differ among management types. Canonical correspondence analysis revealed that 32% of the variability in the small-mammal community could be explained by habitat character- istics and that variables describing availability of coarse woody debris, as well as presence of shrubs in the understory, may create conditions favorable to many small- mammal species in these habitats.