Deserts and Desertification

A desert is an ecosystem in an arid zone in which sand dunes cover the land and sandstorms often occur. Although desert vegetation is sparse, it plays an important role in ecosystem structure and function. Desertification is one of the most severe environmental problems today. Land desertification can be controlled through many measures, such as eco-villages, eco-agriculture, biodiversity conservation, and the combination of engineering and biology. This edited volume provides new insights into the pattern of desert ecosystems and the progress of desertification control. It is a useful resource for researchers in ecology, forestry, and land desertification control

Integrated Applications of Geo-Information in Environmental Monitoring

This book focuses on fundamental and applied research on geo-information technology, notably optical and radar remote sensing and algorithm improvements, and their applications in environmental monitoring. This Special Issue presents ten high-quality research papers covering up-to-date research in land cover change and desertification analyses, geo-disaster risk and damage evaluation, mining area restoration assessments, the improvement and development of algorithms, and coastal environmental monitoring and object targeting. The purpose of this Special Issue is to promote exchanges, communications and share the research outcomes of scientists worldwide and to bridge the gap between scientific research and its applications for advancing and improving society

Integrated Ecosystem Assessment of Western China

Western Development is an important strategy of China Government. The ecological environment in the western region of China is very fragile, and any improper human activity or resource utilization will lead to irrecoverable ecological degradation. Therefore, the integrated ecosystem assessment in the western region of China is of great significance to the Western Development Strategy. This project, Integrated Ecosystem Assessment of Western China (MAWEC), will provide very important scientific foundations for both the central and local governments to make decisions on ecological construction, thus assuring the successful implementation of the Western Development Strategy. Meanwhile, MAWEC as one of the MA sub-global assessments is contributing to strengthen capability in boosting the development of the ecological science, interaction between different subjects, and combination between scientific research and practice, and pushing forward international cooperation in the relevant fields

Spatial Heterogeneity of Forest-Steppes

Forest-steppes occupy a wide zone between Eurasian closed canopy forests and open steppes and feature a mosaic of woody and herbaceous vegetation. Due to the occurrence of structurally, compositionally, and environmentally strongly different habitats in close proximity, high spatial heterogeneity is one of the key characteristics of forest-steppe ecosystems. This volume presents ten contributions examining forest-steppe heterogeneity and its effects on environmental factors, plant communities, and animals

Design with the Desert

Typical development in the American Southwest often resulted in scraping the desert lands of the ancient living landscape, to be replaced with one that is human-made and dependent on a large consumption of energy and natural resources. This transdisciplinary book explores the natural and built environment of this desert region and introduces development tools for shaping its future in a more sustainable way. It offers valuable insights to help promote ecological balance between nature and the built environment in the American Southwest-and in other ecologically fragile regions around the world

A phylogenetic perspective on the ecology, morphology and physiology of grasses

Grasslands cover a third of the Earth's surface, and have great economic and ecological importance. The finding of multiple independent origins of C4 photosynthesis in grasses has motivated an integration of phylogeny, biogeography, ecology and physiology. Phylogenetic niche conservatism (PNC) is the tendency of closely related species to share similarities in ecological niches, morphological and physiological traits over time. Contrasting relationships between the biogeographical patterns of different grass lineages and rainfall gradients provided early evidence of PNC, but these were confounded with photosynthetic type. Therefore this thesis compared phylogeny and photosynthetic type as explanations of grass ecology, and tested how PNC changes at different spatial scales by investigating habitat water and morphological and physiological traits. Globally, divergence of the two largest C4 grass subfamilies was responsible for phylogenetic signals in both morphological and habitat traits, indicating PNC. Regionally, the Inner Mongolian steppe provided strong climatic gradients to study how environmental filtering and niche partitioning affected community assembly. PNC was supported in this species assembly in both morphological and habitat traits, but was weaker at the habitat scale. A field study along habitat gradients found that niche partitioning existed both among and within communities and the wide niche breadth of most species weakened phylogenetic signals. Morphologically, some traits were more conservative than others, especially stomatal traits. Ecophysiological traits were neither phylogenetically nor habitat dependent. Greenhouse comparison of C4 grasses testified that phylogeny interacted with both C4 subtype and habitat type. Morphologically, only stomatal traits showed phylogenetic signals. Ecophysiologically, leaf hydraulics showed overall associations with leaf structure, and NAD-me species in Chloridoideae had drought tolerant leaf water release characteristics. In conclusion, it is inappropriate to consider all C4 grasses as a single functional type at the global and regional scales since phylogeny explains distribution, morphological and habitat traits. At the community and habitat levels, PNC becomes weaker when phylogeny interacts with both photosynthetic type and environmental factor.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Large area forest stem volume mapping using synergy of spaceborne interferometric radar and optical remote sensing: a case study of northeast chin

More than a decade of investigations on the use of the interferometric ERS-1/2 tandem coherence for forest applications have increased the understanding of the behaviour of C-band repeat-pass coherence over forested terrain. It has been shown that under optimal imaging conditions, ERS-1/2 tandem coherence can be used for stem volume retrieval with accuracies in the range of ground surveys. Large-area applications of ERS-1/2 tandem coherence are rare though. One of the main limitations concerning large-area exploitation of the existing ERS-1/2 tandem archives for forest stem volume retrieval is related to the considerable dependence of repeat-pass coherence upon the meteorological (rain, temperature, wind speed) and environmental (soil moisture variations, snow metamorphism) acquisition conditions. Conventional retrieval algorithms require accurate forest inventory data for a dense grid of forest sites to tune models that relate coherence to stem volume to the local conditions. Accurate forest inventory data is, however, a rare commodity that is often not freely available. In this thesis, a fully automated algorithm was developed, based on a synergetic use of the MODIS Vegetation Continuous Field product (Hansen et al., 2002), that allowed the training of the Interferometric Water Cloud Model IWCM (Askne et al., 1997) without further need for forest inventory data. With the new algorithm it was possible to train the IWCM on a frame-by-frame basis and thus to account for the spatial and temporal variability of the meteorological and environmental acquisition conditions. The new algorithm was applied to a multi-seasonal ERS-1/2 tandem dataset covering Northeast China that was acquired between 1995 and 1998 with baselines up to 400 m

A Multi-Archive Reconstruction of Holocene Summer and Winter Monsoon Variability in NW South Asia

This thesis investigates the paleoclimate of the Indus River Basin and surrounding areas of northwest (NW) South Asia over the last 12,000 years, covering a critical period of human history. The region’s climate is characterized by two overlapping rainfall systems: the Indian Summer Monsoon (ISM) and the Indian Winter Monsoon (IWM). A shift in these monsoon systems has been documented throughout South Asia at 4.2 ka BP, with potential effects on the development and decline of the Indus Civilization (c. 5- 3.6 ka BP). This thesis examines the connection between climate and cultural shifts by providing new records from three climate archives spanning 1500 km from the Arabian Sea to the Thar Desert and Himalayan Mountains. The chapters feature δ¹⁸O and δ¹³C of three foraminifer species in marine core 63KA over 8.8-7.6 ka BP and 5.4-3.0 ka BP, gypsum from three Holocene Thar Desert playa lakes, and sub-annually resolved trace element and stable isotope data from DHAR-1 speleothem covering 4.2-2.5 ka BP. The major findings from this thesis contribute to a more comprehensive understanding of climate change in NW South Asia throughout the Holocene. The three Thar Desert playa lakes began accumulating gypsum c. 11 ka BP, aligning with a post- glacial strengthening ISM. Prismatic gypsum crystals and uniformly high δ¹⁸O of gypsum hydration water from early-mid Holocene deposits suggest relatively deep lake levels during this phase. Similarly, the δ¹⁸O of marine core 63KA foraminifer species dwelling in surface and thermocline layers demonstrate a stronger ISM over 8.8-7.6 ka BP and a strengthening IWM from 8.8-8.6 ka BP. By 4.8 ka BP, the ISM started weakening, but IWM strength peaks from 4.5-4.3 ka BP. A wet period c. 5-4.4 ka BP is also apparent from high δ¹⁸O of gypsum hydration water at Karsandi playa. The late Holocene droughts after 4.2 ka BP are well-documented by the precise (age error ± 18 years) DHAR-1 reconstruction, which tracks ISM strength via δ¹⁸O and winter aridity using δ¹³C, Sr²⁺ U²⁺, and Ba²⁺. Weakened ISM and IWM both contributed to the 230-year drought period with three distinct arid phases (4.2-4.17 ka BP, 4.14-4.08 ka BP, and 4.06-3.97 ka BP). Core 63KA shows minimum Indus River discharge and weakened IWM over the same interval, whereas Lunkaransar playa shows a protracted lake level decline, and aeolian sand replaces gypsum deposition at Karsandi by 3.2 ka BP. Shallow playa systems briefly recover at Lunkaransar and Khajuwala during the late Holocene, but Khajuwala eventually desiccates permanently.Tworains ERC grant 648609 WIHM ERC grant 339694 QUEST H2020 Marie Skodowska-Curie actions 69103