Changes in NDVI and human population in protected areas on the Tibetan Plateau

Understanding the Tibetan Plateau’s role in environmental change has gained increasing scientific attention in light of warming and changes in landmanagement. We examine changes in greenness over the Tibetan Plateau using the Normalized Difference Vegetation Index (NDVI) from the Global Inventory Monitoring and Modeling Study (GIMMS3g) to identify significant changes over the entire plateau, six ecoregions, and protected areas based on a multiyear time series of July imagery from 1982 to 2015. We also test whether there have been changes in human populations in protected areas. There has been relatively little change in mean NDVI over the Tibetan Plateau or ecoregions, however, there were significant changes at the pixel level. There are sixty-nine protected areas on the Tibetan Plateau; sixtytwo protected areas had no significant change in mean NDVI and seven protected areas experienced a significant increase in NDVI. There has been an increase in population within protected areas from 2000 to 2015; however, mean populations significantly increased in two protected areas and significantly decreased in four protected areas. Results suggest a slow greening of the Tibetan Plateau, ecoregions, and protected areas, with a more rapid greening in northern Tibet at the pixel level. Most protected areas are experiencing minor changes in NDVI independent of human population

Pemodelan Habitat Potensial Tumbuhan Lebah Apis dorsata di Membalong, Belitung

The forest becomes a habitat for honey bees to carry capacity for the supply of feed sources. Apis dorsata requires the availability of plants for supplying nectar and pollen. Traditional system in Belitung uses rafters for the efficiency of honey harvesting. Studies about preference habitats for bee forage become important to perform conservation of the honey bees. Therefore, the objective of this study was to (1) identify the composition, structure distribution patterns and vegetation profiles, (2) identify the area of the appropriate habitat model and environmental variables that influence the carrying capacity to provide bee forage of A. dorsata. Purposive sampling was used to analyze vegetation structure, distribution patterns, and vegetation profiles. The determination of the distribution of species is obtained from the Morishita index. We used MaxEnt for species distribution modeling to predict the potential plant habitat of bee plants. Our results showed that five most highest-importance plants. Myrtaceae is a family with dominant compositions and INP such as Melaleuca cajuputi, Tristaniopsis obovata, and Eugenia leptantha. The structure of other families such as Theaceae (Schima wallichii), and Clusiaceae (Calophyllum pulcherrimum), are the species that have the highest importance. The pattern of distribution of bee forage is clumped. The canopy cover around the honeycomb area tends to be relatively open. Based on the modeling habitat, categories with very appropriate for the presence of bee forage not spread throughout Membalong Regency with a percentage of the area (4.86%) and in the buffer zone (10.53%), environmental variables that influence the distribution are temperature seasonality, maximum temperature warmest month, slope, precipitation on warmest quarter and soil ph.   Keywords: habitat modeling, rafter, spatial distribution, vegetation analysis, vegetation profile

Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) at Global Scales

Satellite observations of surface reflected solar radiation contain informationabout variability in the absorption of solar radiation by vegetation. Understanding thecauses of variability is important for models that use these data to drive land surface fluxesor for benchmarking prognostic vegetation models. Here we evaluated the interannualvariability in the new 30.5-year long global satellite-derived surface reflectance index data,Global Inventory Modeling and Mapping Studies normalized difference vegetation index(GIMMS NDVI3g). Pearsons correlation and multiple linear stepwise regression analyseswere applied to quantify the NDVI interannual variability driven by climate anomalies, andto evaluate the effects of potential interference (snow, aerosols and clouds) on the NDVIsignal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systemswhere in some regions and seasons 40 of the NDVI variance could be explained byprecipitation anomalies. Temperature correlations were strongest in northern mid- to-high-latitudes in the spring and early summer where up to 70 of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America,winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wetseason precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models

ENVIRONMENTAL CHANGE AND THE AGRO-PASTORALIST LIVELIHOOD IN THE ANDES OF PERU

This dissertation research focuses on a high elevation Andean social-ecological system. It examines system linkages between climate, grazing pasture (wetlands), and agro-pastoralist livelihood strategies in an indigenous peasant community. Working within the conceptual framework of complex systems dynamics and sustainable livelihoods analysis, methods and concepts are synthesized from the disciplines of climatology, hydrology, remote sensing and political ecology, and results contribute to the transdisciplinary literature on vulnerability analysis within the context of environmental change. In the Andes of southern Peru livelihoods are based on agro-pastoralist activities that rely on access to natural resources in the puna ecosystem. The majority of pastoralists in the study region are indigenous Quechua who in the higher elevations raise herds predominantly of alpaca and sheep. This region in Peru has the highest density of alpacas and is a national leader in the production of fiber. The people in the District of Nuñoa are extremely proud of their alpaca herding heritage and have recently declared the district to be the “World capital and patrimony of the Suri alpaca”. Alpaca are therefore both economically and culturally important. Together with other members in the camelidae family (llama, vicuña, and guanaco), alpaca are well suited to the high elevation puna ecosystem. Wetlands in the puna, known as bofedales, have hydrological and biological characteristics that make them a vital resource to the pastoralist livelihood. Climatic and environmental perturbations may be more pronounced in mountain regions and the affects to local water balance, ecosystems, and humans may be more profound. The sensitivity, adaptive capacity, and hence vulnerability of individuals, groups, and livelihoods to perturbations is a complex function of social, political, and environmental factors. This research uses a hierarchy of spatial scales to understand climate variability in the region as well as spatial and temporal changes in the natural resource base. A case study of an agro-patoralist community allows for the characterization of two disturbance regimes (climate and land use and management) and the linkages between components in the herding system and climate system. The results indicate that there is periodicity in the regional hydroclimatology but a deterioration of the resource base in the watershed. Economic and political factors may be contributing to the overuse of natural pastures which increases the future vulnerability of alpaca herders to environmental change in the Nuñoa watershed

On the Variation of NDVI with the Principal Climatic Elements in the Tibetan Plateau

Abstract: Temperature and precipitation have been separately reported to be the main factors affecting the Normalized Difference Vegetation Index (NDVI) in the Tibetan Plateau. The effects of the main climatic factors on the yearly maximum NDVI (MNDVI) in the Tibetan Plateau were examined on different scales. The result underscored the observation that both precipitation and temperature affect MNDVI based on weather stations or physico-geographical regions. Precipitation is the main climatic factor that affects the vegetation cover in the entire Tibetan Plateau. Both annual mean precipitation and annual mean precipitation of the growing period are related with MNDVI, and the positive correlations are manifested in a linear manner. By comparison, the weakly correlated current between MNDVI and all the temperature indexes is observed in the study area

Linkages between Atmospheric Circulation, Weather, Climate, Land Cover and Social Dynamics of the Tibetan Plateau

The Tibetan Plateau (TP) is an important landmass that plays a significant role in both regional and global climates. In recent decades, the TP has undergone significant changes due to climate and human activities. Since the 1980s anthropogenic activities, such as the stocking of livestock, land cover change, permafrost degradation, urbanization, highway construction, deforestation and desertification, and unsustainable land management practices, have greatly increased over the TP. As a result, grasslands have undergone rapid degradation and have altered the land surface which in turn has altered the exchange of heat and moisture properties between land and the atmosphere. But gaps still exist in our knowledge of land-atmosphere interactions in the TP and their impacts on weather and climate around the TP, making it difficult to understand the complete energy and water cycles over the region. Moreover, human, and ecological systems are interlinked, and the drivers of change include biophysical, economic, political, social, and cultural elements that operate at different temporal and spatial scales. Current studies do not holistically reflect the complex social-ecological dynamics of the Tibetan Plateau. To increase our understanding of this coupled human-natural system, there is a need for an integrated approach to rendering visible the deep interconnections between the biophysical and social systems of the TP. There is a need for an integrative framework to study the impacts of sedentary and individualized production systems on the health and livelihoods of local communities in the context of land degradation and climate change. To do so, there is a need to understand better the spatial variability and landscape patterns in grassland degradation across the TP. Therefore, the main goal of this dissertation is to contribute to our understanding of the changes over the land surface and how these changes impact the plateau\u27s weather, climate, and social dynamics. This dissertation is structured as three interrelated manuscripts, which each explore specific research questions relating to this larger goal. These manuscripts constitute the three primary papers of this dissertation. The first paper documents the significant association of surface energy flux with vegetation cover, as measured by satellite based AVHRR GIMMS3g normalized difference vegetation index (NDVI) data, during the early growing season of May in the western region of the Tibetan Plateau. In addition, a 1°K increase in the temperature at the 500 hPa level was observed. Based on the identified positive effects of vegetation on the temperature associated with decreased NDVI in the western region of the Tibetan Plateau, I propose a positive energy process for land-atmosphere associations. In the second paper, an increase in Landsat-derived NDVI, i.e., a greening, is identified within the TP, especially during 1990 to 2018 and 2000 to 2018 time periods. Larger median growing season NDVI change values were observed for the Southeast Tibet shrublands and meadows and Tibetan Plateau Alpine Shrublands and Meadows grassland regions, in comparison to the other three regions studied. Land degradation is prominent in the lower and intermediate hillslope positions in comparison to the higher relative topographic positions, and change is more pronounced in the eastern Southeast Tibet shrublands and meadows and Tibetan Plateau Alpine Shrublands and Meadows grasslands. Geomorphons were found to be an effective spatial unit for analysis of hillslope change patterns. Through the extensive literature review presented in third paper, this dissertation recommends using critical physical geography (CPG) to study environmental and social issues in the TP. The conceptual model proposed provides a framework for analysis of the dominant controls, feedback, and interactions between natural, human, socioeconomic, and governance activities, allowing researchers to untangle climate change, land degradation, and vulnerability in the Tibetan Plateau. CPG will further help improve our understanding of the exposure of local people to climate and socio-economic and political change and help policy makers devise appropriate strategies to combat future grassland degradation and to improve the lives and strengthen livelihoods of the inhabitants of the TP