Level Of Land Degradation Research Articles

Land Degradation Affects Soil Microbial Properties, Organic Matter Composition, and Maize Yield

Land degradation severely affects soil functions, thereby weakening crop productivity. However, the quantitative effects of the soil organic matter (SOM) composition and soil microbial properties on maize yield remain unclear under different levels of land degradation. Here, a gradient of land degradation was selected for sampling in the Horqin Sandy Land in northeast China. The results show that the relative abundances of aliphatic and aromatic groups decreased by 21.51% and 86.01% with increasing land degradation, respectively, and the considerable increase in polysaccharide groups led to a decrease in stability and resistance to SOM decomposition. Microbial properties, such as microbial biomass carbon, basic respiration, qCO2, and enzyme activities, decreased as a result of land degradation. The phospholipid fatty acid content and the ratio between bacteria and fungi markedly decreased with an increasing level of land degradation, and the ratio of G+ to G− markedly increased. Correlation analysis confirmed that the microbial properties were significantly related to the SOM composition, and the random forest model indicated that fungi were key factors affecting maize yield (7.15%, p < 0.05). Moreover, the results of the structure equation modelling revealed that land degradation reduced the soil physiochemical properties, resulting in a decrease in microorganisms, causing variations in the SOM composition and directly leading to a decrease in crop yield. The effect of microorganisms (β = 0.84 ***) on maize yield was greater than that of the SOM composition (β = 0.53 **). Our investigation can provide a theoretical basis for the conservation of the cropland in Horqin Sandy Land.

PROBLEMS OF LAND RESOURCES USE

The article is devoted to the problems of land protection and rational use. In the study, we analyse the factors leading to degradation and loss of soil fertility. We determined that the negative impact on land is mainly related to the anthropogenic factor. The author points out the role of land as the core national wealth, which, according to the Constitution of Ukraine, is under the special protection of the state. Agricultural lands make up the largest area, but their condition, as well as the condition of other lands, is a matter of concern. We note that the struggle of world powers for economic leadership hinders the environmental problems solution. The article determines that the problems of the use of land resources in Ukraine have only worsened in recent years. Achievements in the agricultural sphere are due to the intensive use and depletion of soils. Intentional and unintentional impact on the earth worsens its condition. The impossibility of adequately calculating the probability of unintended effects on the environment exacerbates the problem. The anthropogenic factor is the main reason for the negative dynamics of the surrounding environment, particularly land resources. Close cooperation of all parties is required to remedy the current situation: land users/land owners, on the one hand, and the state and international organisations, on the other. Scientists and their ideas should be intermediaries between land users/land owners, the state, and international organisations. We propose to strengthen the role of the government in solving problems related to the state of land and their cooperation with international organisations in the fight against desertification and to achieve a zero level of land degradation. We also propose measures to reduce the level of land degradation to reach a neutral level of degradation. At the international level, the ‘United Nations Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification, Particularly in Africa’ was adopted. We suggest considering international standards in the effective management of land resources and the experience in forming and implementing land management systems. Keywords: degradation, desertification, land, soil, concept, convention, fertility.

Land potential assessment and trend-analysis using 2000-2021 FAPAR monthly time-series at 250 m spatial resolution.

The article presents results of using remote sensing images and machine learning to map and assess land potential based on time-series of potential Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) composites. Land potential here refers to the potential vegetation productivity in the hypothetical absence of short-term anthropogenic influence, such as intensive agriculture and urbanization. Knowledge on this ecological land potential could support the assessment of levels of land degradation as well as restoration potentials. Monthly aggregated FAPAR time-series of three percentiles (0.05, 0.50 and 0.95 probability) at 250 m spatial resolution were derived from the 8-day GLASS FAPAR V6 product for 2000-2021 and used to determine long-term trends in FAPAR, as well as to model potential FAPAR in the absence of human pressure. CCa 3 million training points sampled from 12,500 locations across the globe were overlaid with 68 bio-physical variables representing climate, terrain, landform, and vegetation cover, as well as several variables representing human pressure including: population count, cropland intensity, nightlights and a human footprint index. The training points were used in an ensemble machine learning model that stacks three base learners (extremely randomized trees, gradient descended trees and artificial neural network) using a linear regressor as meta-learner. The potential FAPAR was then projected by removing the impact of urbanization and intensive agriculture in the covariate layers. The results of strict cross-validation show that the global distribution of FAPAR can be explained with an R2 of 0.89, with the most important covariates being growing season length, forest cover indicator and annual precipitation. From this model, a global map of potential monthly FAPAR for the recent year (2021) was produced, and used to predict gaps in actual vs. potential FAPAR. The produced global maps of actual vs. potential FAPAR and long-term trends were each spatially matched with stable and transitional land cover classes. The assessment showed large negative FAPAR gaps (actual lower than potential) for classes: urban, needle-leave deciduous trees, and flooded shrub or herbaceous cover, while strong negative FAPAR trends were found for classes: urban, sparse vegetation and rainfed cropland. On the other hand, classes: irrigated or post-flooded cropland, tree cover mixed leaf type, and broad-leave deciduous showed largely positive trends. The framework allows land managers to assess potential land degradation from two aspects: as an actual declining trend in observed FAPAR and as a difference between actual and potential vegetation FAPAR.

Possible Integration of Soil Information into Land Degradation Analysis for the United Nations (UN) Land Degradation Neutrality (LDN) Concept: A Case Study of the Contiguous United States of America (USA)

Soil makes important contributions to the United Nations (UN) Land Degradation Neutrality (LDN) concept and targets; however, currently, soil is not integrated into measurable information (e.g., indicators, metrics) to monitor land degradation (LD) patterns and trends. This study examines the role of soil in LDN in the UN Convention to Combat Desertification (UNCCD), and UN Sustainable Development Goal (SDG 15: Life on Land). This study is specifically focused on the LDN and biodiversity loss as they relate to an indicator 15.3.1 Proportion of land that is degraded over total land area. Tracking of LD status can be improved by using detailed soils databases combined with satellite-derived land cover maps. This study has applied these newly improved methods to quantify and map the anthropogenic LD status and trends in the contiguous United States of America (USA), as well as to identify potential land areas for nature-based solutions (NBS) to compensate for LD. Anthropogenic LD in 2016 in the contiguous USA affected over two million square kilometers, about one-third of the country’s total area, with high variability by state. Between 2001 and 2016, LD in the USA showed an overall increase of 1.5%, with some states exhibiting increases in degraded land while other states had overall improvements to their land. All ten soil orders present in the contiguous USA have been anthropogenically degraded, with Mollisols, Alfisols, and Vertisols having the highest LD levels. Compensating for LD requires a variety of strategies and measures (e.g., NBS), which often require additional land. In 2016, the potential land area for NBS was over two million square kilometers, an area approximately equal to that of degraded land. Some of the states that have high proportions of land available for potential NBS are dominated by soils (Aridisols) typical of deserts and therefore may have less promise for NBS. The variability of LD needs to be evaluated at finer spatial scales for realistic LDN analysis.

Land use/cover and land degradation across the Eurasian steppe: Dynamics, patterns and driving factors

Despite the ecological and socio-economic importance of Eurasian steppe, the land use/cover change, land degradation and the threats facing this precious ecosystem still have not been comprehensively understood. Taking advantages of the land use/cover change monitoring platform (FROM-GLC Plus), this study developed the annual land use/cover maps during 2000–2022, and the land use/cover change, especially the change of grassland, was further analyzed. The grassland area exhibited a net increase, predominantly transformed from cropland, forest, and bareland, accounting for 17.64 %, 31.91 %, and 45.60 %, respectively. To monitor land degradation, we adopted the framework suggested by the United Nations Convention to Combat Desertification (UNCCD). According to the monitoring result, grassland constituted the highest proportion of degraded land (39.82 %). This may due to its dominance in the Eurasian steppe's land use/cover, as the extent of grassland degradation (1.92 %) was lower than the overall land degradation level (2.83 %) across the region. To offer tailored and sustainable development recommendations, we quantified the driving factors behind land dynamics using the geographical detector model and convergent cross mapping (CCM), considering both spatial and temporal dimensions. Environmental and socio-economic factors, such as precipitation, temperature, urbanization, mining and grazing intensity, etc., were integrated into the analysis. We found that urbanization, cropland and moisture distribution emerged as key drivers influencing land degradation's spatial distribution in the Eurasian steppe, while temperature variations between years impacted vegetation changes. This research thus provides a deeper understanding of the region's land dynamics, enhancing comprehensive monitoring of the Eurasian steppe's land dynamics. Moreover, it serves as a foundation for policymakers and land managers to devise conservation strategies and sustainable development initiatives for this critical ecosystem.

The Characteristics of Rainfall-Runoff Generation and Its Influencing Factors in a Desert Steppe, China

Understanding the effect of land surface characteristics on rainfall-runoff generation is crucial in mastering the mechanisms of soil and water conservation. To characterize rainfall-runoff generation in desert steppes and to quantify the contribution of different influencing factors, a field-simulated experiment with three land degradation levels and three rainfall intensities (RIs) was conducted in the Inner Mongolia Desert Steppe. The results revealed that rainfall-runoff generation in different degraded plots at various RIs differed significantly. The runoff was generated faster and accumulated larger volumes under high RIs and heavy degradation levels (HDs) in comparison with generation under moderate/light degradation levels (MDs/LDs) and moderate/low RIs. The accumulated runoff over 40 min under a high RI on the HD plot is 153.37 L, which is much larger (0.77 L) than that under a low RI on the LD plot. The result from the structural equation model (SEM) indicated that RI is the most important factor directly driving rainfall-runoff generation, and its standardized path coefficient reached a value of 0.52. The vegetation condition is the second direct factor, with a standardized path coefficient of −0.51. However, the soil water content (SWC) has an indirect impact on rainfall-runoff generation through affecting vegetation conditions. So, interactions also exist between variables such as vegetation and soil. Therefore, the rainfall-runoff generation in the desert steppe may be mitigated through an enhancement of the vegetation and soil properties or through optimizing the interaction relationship between soil and vegetation.

Complex method for land degradation estimation

Satellite data of high spatial resolution have become publicly available since the launch of the EU Copernicus program, and their automated processing methods for solving a large number of diverse applied problems have received further development. Our task in this article is to analyze the dynamics of the land degradation level using land degradation assessment approaches based on satellite monitoring and taking appropriate measures. Within this work authors have developed the complex method for land degradation estimation that uses different schemes for separate land cover and crop types at country level based on satellite and modelling data. The deforestation was considered as land degradation in forest areas. For agricultural land, land degradation is determined by comparing the actual leaf area index (LAI) with the simulated (ideal) LAI, and for uncultivated land it is based on normalized difference vegetation index trend analysis from satellite information.

Desertification risk fuels spatial polarization in \u2018affected\u2019 and \u2018unaffected\u2019 landscapes in Italy

Southern Europe is a hotspot for desertification risk because of the intimate impact of soil deterioration, landscape transformations, rising human pressure, and climate change. In this context, large-scale empirical analyses linking landscape fragmentation with desertification risk assume that increasing levels of land vulnerability to degradation are associated with significant changes in landscape structure. Using a traditional approach of landscape ecology, this study evaluates the spatial structure of a simulated landscape based on different levels of vulnerability to land degradation using 15 metrics calculated at three time points (early-1960s, early-1990s, early-2010s) in Italy. While the (average) level of land vulnerability increased over time almost in all Italian regions, vulnerable landscapes demonstrated to be increasingly fragmented, as far as the number of homogeneous patches and mean patch size are concerned. The spatial balance in affected and unaffected areas—typically observed in the 1960s—was progressively replaced with an intrinsically disordered landscape, and this process was more intense in regions exposed to higher (and increasing) levels of land degradation. The spread of larger land patches exposed to intrinsic degradation brings to important consequences since (1) the rising number of hotspots may increase the probability of local-scale degradation processes, and (2) the buffering effect of neighbouring (unaffected) land can be less effective on bigger hotspots, promoting a downward spiral toward desertification.

Самообеспеченность основными видами продовольствия во Владимирской области

The article substantiates the choice of such an indicator as self-sufficiency in basic types of food as a criterion for assessing food security at the municipal level. The methodology proposed by the authors for calculating indicators of self-sufficiency in basic types of food at the municipal level is described in detail in earlier publications. The results of the analysis of the data obtained on self-sufficiency in such types of products as potatoes, vegetables, meat, milk, fruits and berries in the municipal districts of the Vladimir region in dynamics in the period 2010-2021 are presented. The leaders in self-sufficiency of the main types of food in 2021 were Sobinsky and Yuriev-Polsky municipal districts located in the zone of the most fertile gray forest soils. Indicators of self-sufficiency in meat are below the norm, with the exception of Sobinsky and Yuriev-Polsky districts. The situation for milk is somewhat better, self-sufficiency indicators are normal and higher in six municipalities: Kovrovsky, Petushinsky, Selivanovsky, Sobinsky, Sudogodsky and Yuriev-Polsky; positive dynamics was observed in the period 2010-2021. For vegetables in all municipalities of the Vladimir region in the period 2010-2021, negative dynamics was observed, and as of 2021, low indicators of self-sufficiency were noted, with the exception of Vyaznikovsky and Yuriev-Polsky districts. An assessment of the relationship between self-sufficiency of the main types of products and the level of land degradation in the municipalities of the Vladimir region is given.

Концептуальні положення сталого менеджменту добрив в Україні

The article presents the results of the analysis of the main national and international documents, which are evidence of how the global deterioration of the quality and state of soil resources catalyzed the process of awareness by the international community of the need to develop and implement mechanisms for preserving the productive and ecological functions of the soils of agrocenoses in order to achieve a neutral level of land degradation. One of the main blocks of sustainable management of soil resources is the sustainable management of fertilizers, the use of which significantly increases the productivity of agricultural crops, affects the quality of the soil, but may have certain environmental risks. The purpose of the research is to define conceptual approaches to sustainable fertilizer management that are harmonized with the requirements of the International Fertilizer Code and adapted to the conditions of Ukraine. The research was conducted using general scientific, structural-functional and abstract-logical methods. The analysis of the current national base of regulatory documents regarding the management of soil resources and fertilizers indicates its improvement, including through the ratification and implementation of international regulatory documents. Within the framework of the international integration of the country, a conceptual approach to the sustainable management of fertilizers in Ukraine is proposed, which is aimed at reorienting the vector of actions from "controlling the impact" to "preventing the impact", where the object of action is the soil, and the subject of action is fertilizers. Subjects of ensuring sustainable management of fertilizers - authorities, manufacturers of fertilizers, including from secondary raw materials, scientific institutions of the National Academy of Agrarian Sciences and the State Institution "Soil Protection Institute of Ukraine", higher educational institutions of agronomic and environmental specialties, organizations and associations of various forms of ownership , whose activities concern fertilizers, agrochemical laboratories and farms of various forms of ownership. Sustainable fertilizers management, harmonized with international guidelines, is based on such principles as objectivity, representativeness, regulation, scientificity, systematicity, causality, environmental friendliness, benchmarking and informativeness. Based on the results of the analysis, a set of measures to ensure the sustainable management of fertilizers in Ukraine is proposed, which consists of interconnected and complementary blocks – regulatory, organizational, informational and technological (fertilizer production and application), which have a number of relevant tasks aimed at ensuring a balanced and standardized application of fertilizers in the country's agriculture, preservation of productive and ecological functions of soils, prevention of the development of degradation processes in order to achieve their neutral level, guarantee of food stability and ecological security of the country.

Anti-erosion reclaim development and its economic efficiency

This paper considers the issues of the efficiency of agricultural production in the context of the globalization of the markets for agricultural raw materials and food and the increased competition in this regard. Modern realities and the adopted new Doctrine of Food Security of the Russian Federation, adopted in 2020, require an immediate solution to the problems of ensuring the country's food security by increasing the production of high-quality, environmentally friendly, and, most importantly, economically competitive agricultural products, which is not possible without intensifying production processes. However, the pursuit of high yields and high efficiency of agricultural commodity production often leads to the degradation of the prickly factor of production, namely, land. The paper presents the results of the analysis of the level of land degradation in the Republic of Tatarstan and identifies priority areas for combating erosion in agriculture. Measures to combat soil erosion are experimentally substantiated. The practical significance of the research results lies in the fact that they can not only contribute to the development of the agro-industrial complex and other sectors of the economy, improve soil fertility, the dynamic growth of agricultural products, reduce the disposal of agricultural land and create new jobs but also ensure the preservation and restoration of the Volga River. The results show that the ecological efficiency of one anti-erosion structure in combination with soil protection measures protects an average of 120 hectares of land from further development of erosion processes and is economically paid off by the results of two years of economic activity on protected lands.

The assessment of soil and land degradation in Volgograd region, the case of agricultural farm Donskoe

This study is aimed at assessing soil and land degradation of agricultural farmlands of Kalachev district, Volgograd region. To identify the level of land degradation, soil properties of samples taken in summer 2019 in that area were compared with average values for the same area obtained by YUZHGIPROZEM in 1982 [1]. The calculations to evaluate land degradation were based on “Methodology for determine the extent of damage of soil and land degradation” [2]. The conducted chemical and physical analysis of sampled soils demonstrated the highest level of land degradation in that area. The soils were proven to have an increase in exchangeable sodium percentage (ESP); 52% of the agricultural lands of Donskoe demonstrated these values. The assessment of the other land degradation parameters such as density, mobile phosphorus, exchange potassium, heavy metals concentration and arsenic content, toxic salts and pH (H2O) revealed lower level of degradation and insignificant occurrence in the farmland territory.

Land degradation assessment using AHP and GIS-based modelling in Duhok District, Kurdistan Region, Iraq

Land degradation is a complex process and significant environmental problem affected by both natural and anthropogenic driving factors. Globally, the prevention of land degradation has become one of the most significant challenges of the twenty-first century. Over the last decade, a marked change was observed in land degradation in the Duhok district of Iraq. Geographic Information System (GIS), Multispectral Remote Sensing satellite image, and Analytic Hierarchy Process are efficient tools for modelling and assessing the risks of land degradation. To analyze land degradation, in this study, various physical and human-induced factors were used in the GIS environment; slope, elevation, drainage, precipitation, geology, vegetation coverage, and land use/land cover. The data were analyzed and weights assigned to each factor using the analytic hierarchy process and mapped using GIS techniques, resulting in a land degradation map. Field observations were carried out to better understand the degree of various factors that contribute to land degradation by using recent technologies and a global positioning system in the study area. The results show that 11.74% and 28.69% of the study area were affected by high and moderate levels of land degradation, respectively, while 34.77% and 24.79% of the study area experienced slight and no degradation, respectively. Slope gradient, rainfall, and distribution of vegetation were identified as the primary causes of land degradation in the area. This method of evaluation is intended to be beneficial to governments and researchers.

Anthropogenic disturbances on antibiotic resistome along the Yarlung Tsangpo River on the Tibetan Plateau: Ecological dissemination mechanisms of antibiotic resistance genes to bacterial pathogens

Human activities can accelerate the antibiotic resistome prevalence and pose threats to ecological safety and public health globally. However, antibiotic resistance gene (ARG) mobility and dissemination into bacterial pathogens under anthropogenic disturbances are still poorly understood. Here, we used a metagenomic approach to profile the biogeography of ARGs and pathogenic antibiotic resistant bacteria (PARB) under anthropogenic disturbances along the Yarlung Tsangpo River. Results showed the ARGs was dominated by bacA gene along the Yarlung Tsangpo River on the Tibetan Plateau. The ARG composition was differently impacted by rapid urbanization and dam construction, which urbanization could promote ARGs resistant to sulfonamide and tetracycline, whereas dam construction could elevate the resistance to chloramphenicol and aminoglycoside. Land use pattern was identified as a critical factor influencing ARG composition under anthropogenic disturbances, as it could directly reflect the land degradation level and indicate the inputs of ARG-selective chemicals of different human activities. Moreover, despite of the lack of variation in ARG relative abundance, PARB were highly promoted by anthropogenic activities, indicating increasing ARG dissemination to pathogen. We found that human-impacted environments harbored high proportion of mobile genetic elements (MGEs), and the MGE carrying ARGs also increased under anthropogenic disturbances in the pathogenic hosts, which confirmed that anthropogenic activities could promote ARG horizontal gene transfer. Furthermore, anthropogenic activities could influence PARB assembly processes. Basically, stochastic processes dominated PARB assembly along the river, and with increasing level of anthropogenic activities, these processes shifted from undominated stochastic processes to dispersal limitation. In summary, this study provides useful strategies in watershed resistome management and reduction of ARG dissemination to pathogens, which should consider the mode and intensity of human activity and its potential influence on horizontal gene transfer and assembly processes.

Degradasi Lahan dan Implikasinya terhadap Rencana Pola Ruang di Daerah Dataran Tinggi

Land degradation is a phenomena of the decreasing in land use function, potential use and irreplaceable organism. Many causes result in land degradation such as soil erosion, rain erosion which are all accelerated by human activities example agricultural activity. Increased agricultural activity is caused by an increase in population and also increasing food needs. Land exploitation for agricultural activities result in land degradation such as planting on conservation areas that cause erosion. Kledung Sub-district is one of the regions that practices massive agricultural land use and plants in a conservation land. Practices in Kledung Sub-district have caused floods and soil erosion in Kledung Sub-district in the last few years. The purpose of this study was to determine the level of land degradation that occurred in Kledung Sub-district and its implications for the land use planning to increase awareness of various parties about the dangers of land degradation. This research was conducted primarily by observation and secondary b examining documents about the indicators causing land degradation and conducting descriptive and quantitative analyzes. The quantitative analyze is using RUSLE (Revised Universal Soil Loss Equation). The analysis shows that the majority of erosion according to the Ministry of Forestry is moderate (>60-80 tons/ha/yr) covering1.231,01 Ha and according to Hammer which is very high (>100 tons/ha/yr) covering 469,62 Ha or 12,7% of the total area of Kledung Sub-district with a high level of erosion hazard it is necessary to evaluate the land use planning of Kledung Sub-district so that it can adjust the land use planning and the erosion hazard level in Kledung Sub-district.

The classification of the level of land degradation as the flood cause in some sub-watersheds at Pesawaran Regency, Lampung

The purpose of this study was to evaluate the distribution and classification of land degradation levels in several sub-watersheds in the Pesawaran Regency. This research employed the survey and non-experimental approaches. The research was conducted in four sub-watersheds of Pesawaran Regency, namely Way Semah, Way Punduh, Way Ratai, and Bulok. Topographic, land-use changes, soil type, and rainfall were the parameters used to assess the degradation of sub-watersheds. The land analysis unit was the unit of interpretation and mapping. The results showed that the dominant factors causing land degradation were changes in land use for settlements and agriculture. The sub-watersheds with the highest degradation was Way Ratai.

Spatial analysis of soil erosion sensitivity using the Revised Universal Soil Loss Equation model in Nyamasheke District, Western Province of Rwanda

AbstractPrevious studies have identified that Nyamasheke District in Rwanda is highly vulnerable to soil erosion. This has led to a loss of fertile soil, with a high level of land degradation. Nevertheless, the district’s spatial and temporal sensitivity to soil erosion remains unknown in different specific parts of the district. This study aimed to analyze spatial soil erosion sensitivity and mapping of vulnerable areas to soil erosion in the district. The Revised Universal Soil Loss Equation (RUSLE) model integrated within a GIS environment was used to estimate annual soil loss for the district. The RUSLE factors were derived from a 30 m resolution digital elevation model, digital soil map of the world, monthly rainfall records from 20 stations within and around the district, and Landsat7/ETM + and Landsat8/OLI imagery. Annual soil loss change was statistically analyzed using an empirical model in the district. The results showed a decreasing trend in soil erosion over time, with the highest annual soil losses estimated at 92.4, 16.1, and 15.1 t ha−1 year−1 in the years 2008, 2015, and 2018, respectively. Areas with the highest soil erosion sensitivity, with soil loss ranging between 10 and 40 t ha−1 year−1, were found in sectors of Kanjongo, Cyato, Rangiro, Macuba, and Karambi.

Assessment and spatial analysis of agricultural land erosion processes in the Samara region

Water and wind erosion of land causes annual damage since it leads to soil degradation and loss of fertility, reducing the economic indicators of agricultural production. Detailed systematization of land resources with an assessment of the scale and level of land degradation provides a basis for ranking areas by relevance and effectiveness of erosion protection. The article assesses the level of degradation of agricultural land in the Samara region by the scale of economic losses under the influence of water and wind erosion of soil with differentiation by administrative districts. The map of eroded lands has been developed. The results of integrated erosion zoning of the territory provide an information basis for identifying priority areas requiring anti-erosion measures, as well as for optimizing the structure of agricultural land use. The main directions of anti-erosion organization of the territory and on-farm land management, depending on the features of the landscape and the nature of damage, have been described.

Caracterização espaço-temporal das tipologias vegetais em ambiente de caatinga degradada: quantificação por meio de variáveis biofísicas

As características climáticas do Semiárido influenciam fortemente a dinâmica da cobertura vegetal e dos solos, além de variáveis ambientais como albedo e índices de vegetação, entre outras. Pesquisas no Semiárido paraibano têm sido realizadas aplicando metodologias para análise dessas variáveis, sobretudo com base em dados orbitais que têm subsidiado o monitoramento das diferentes paisagens no bioma Caatinga. Assim, esse artigo teve como objetivo analisar a distribuição espaço-temporal e a quantificação do albedo da superfície e do índice de vegetação SAVI, em diferentes tipologias vegetais de caatinga na Bacia Experimental de São João do Cariri-PB. Foram utilizadas imagens do sensor TM/Landsat-5. Os resultados mostraram que a estimativa do albedo foi influenciada pela distribuição espacial das tipologias vegetais, o que evidenciou o nível de degradação das terras, enquanto os valores obtidos com a estimativa do SAVI não apresentaram o padrão geralmente definido para a reflectância da vegetação nos períodos chuvosos ou secos na área de estudo.
 Palavras-chave: sensoriamento remoto, degradação, Semiárido.

Land Degradation and Option of Practical Conservation Concepts in Manna Watershed Bengkulu Indonesia

Watershed overcoming deteriorates in its function was indicated by increasing soil erosion and land degradation. The research aims were to determine and map critical land degradation levels and to chose options of practical conservation concepts in Manna watershed. The Manna watershed lays on 102°51'38.2" - 103°10'57.8" long, and 04°0'39.6" - 4°29'38.0" alt covering 72,899.9 ha. The analysis procedures to determine land degradation levels based on Ministry of Forestry Rule (No. P.32/Menhut-11/2009), Procedures of Technical Design on Forest and Land Rehabilitation in Watershed (RTkRHL-DAS). The results showed that the Manna watershed divided in three land uses functions namely protected forest, limited timber forest, and agricultural cultivated areas/settlement. The land starting overcome degradation in covered by 35,318.6 ha or 48,77% of the watershed based on digital mapping using ArcGIS 10.1 software. The lands that categorized the critical level of degradation covered 7,989.5 ha or 11,03% of the watershed, and classified in the high critical level were 169.8 ha or 0,23% of the watershed. Options of conservation practice on the degraded lands in the Manna watershed should implement agro-forestry models because of the physiographical landscape in this area covering by waving to hilly landforms. On the protected forest and limited timber forest should develop agro-forestry with collaborative approaches through social engineering and social forestry. Re-establishing land use of the Manna watershed based on functions of land is the wise options for the sustainable environmental concepts