Vegetation Dynamics Revealed by Remote Sensing and Its Feedback to Regional and Global Climate

This book focuses on some significant progress in vegetation dynamics and their response to climate change revealed by remote sensing data. The development of satellite remote sensing and its derived products offer fantastic opportunities to investigate vegetation changes and their feedback to regional and global climate systems. Special attention is given in the book to vegetation changes and their drivers, the effects of extreme climate events on vegetation, land surface albedo associated with vegetation changes, plant fingerprints, and vegetation dynamics in climate modeling

The hydrology of northern boreal lakes in the Taiga Shield and Plains, Northwest Territories and the importance of catchment characteristics in mediating responses to climate

Freshwater lakes are prominent features across northern boreal regions and are sensitive to changing climate conditions. This study, spanning the 2017-18 ice-free seasons, broadens our understanding of how variable climate and landscape conditions influence subarctic lake hydrology in the North Slave Region near Yellowknife, Northwest Territories (NT), Canada. We studied 20 lakes located within the Taiga Shield and Taiga Plains ecozones through an integrated approach, utilizing water isotope tracers (δ2H and δ18O), lake level changes, local meteorological conditions and remotely sensed catchment data. Lake water isotope data were obtained twice during the ice-free season (May and August) and evaporation/inflow (E/I) ratios were calculated to identify the relative importance of catchment hydrological controls. Hydrological data were compared to measured and modelled catchment characteristics, including relative lake/catchment size, slope, land cover and recent wildfire burn area. Overall, precipitation was a major driver of seasonal and interannual lake hydrological change, while evaporation was a major driver of summer water loss. Relative catchment size (lake area to catchment area (LA/CA)) was found to be an important driver of lake hydrology, however, this relationship is complicated by storage deficits associated with variable meteorological conditions. During wet conditions (e.g., freshet and periods of high rainfall), lakes with larger catchments (low LA/CA) had more positive water balances than lakes with high LA/CA. Under drier conditions, lake catchment size and associated fill-and-spill hydrological connectivity was reduced. Lake basins with high LA/CA (particularly those with shallower depth and greater surface area) were more prone to evaporative water loss. Lake hydrological conditions were less influenced by catchment land cover compositions, including burn area. Findings presented here highlight important drivers of lake water balances in subarctic boreal regions, which are sensitive to ongoing changes in climate. This study is part of a broader research project funded and supported by NWT Cumulative Impact Monitoring Program (CIMP), which is using a multi-proxy, paleo-ecological approach to determine long-term (i.e., 2,000 years) records of hydrology, drought, fire and water quality to inform future policy planning

Climate Change and Environmental Sustainability-Volume 4

Anthropogenic activities are significant drivers of climate change and environmental degradation. Such activities are particularly influential in the context of the land system that is an important medium connecting earth surface, atmospheric dynamics, ecological systems, and human activities. Assessment of land use land cover changes and associated environmental, economic, and social consequences is essential to provide references for enhancing climate resilience and improving environmental sustainability. On the one hand, this book touches on various environmental topics, including soil erosion, crop yield, bioclimatic variation, carbon emission, natural vegetation dynamics, ecosystem and biodiversity degradation, and habitat quality caused by both climate change and earth surface modifications. On the other hand, it explores a series of socioeconomic facts, such as education equity, population migration, economic growth, sustainable development, and urban structure transformation, along with urbanization. The results of this book are of significance in terms of revealing the impact of land use land cover changes and generating policy recommendations for land management. More broadly, this book is important for understanding the interrelationships among life on land, good health and wellbeing, quality education, climate actions, economic growth, sustainable cities and communities, and responsible consumption and production according to the United Nations Sustainable Development Goals. We expect the book to benefit decision makers, practitioners, and researchers in different fields, such as climate governance, crop science and agricultural engineering, forest ecosystem, land management, urban planning and design, urban governance, and institutional operation.Prof. Bao-Jie He acknowledges the Project NO. 2021CDJQY-004 supported by the Fundamental Research Funds for the Central Universities and the Project NO. 2022ZA01 supported by the State Key Laboratory of Subtropical Building Science, South China University of Technology, China. We appreciate the assistance of Mr. Lifeng Xiong, Mr. Wei Wang, Ms. Xueke Chen, and Ms. Anxian Chen at School of Architecture and Urban Planning, Chongqing University, China

Modeling the hydrology, suspended sediments and organic carbon fluxes of the Congo River Basin: the role of the Cuvette Centrale

Le bassin du fleuve Congo (BRC) est le deuxième plus grand bassin de drainage sur Terre après l'Amazone en termes de débit et de superficie du bassin. Il contient également la deuxième plus grande zone de forêt tropicale humide (1,8 million km2) qui abrite également le plus grand gisement de tourbières des tropiques (145 500 km2). La Cuvette Centrale est le bassin quarternaire "sag" situé au centre de ce bassin qui reçoit les flux de tous les principaux affluents situés sur la rive droite, la rive gauche et le cours d'eau supérieur du fleuve Congo. Bien que certaines études en l'hydrologie, sur les sédiments et en biogéochimie de la matière organique aient été réalisées sur ce bassin, il est nécessaire de mieux contraindre les flux latéraux de la matière qui passent par la Cuvette afin d'améliorer la compréhension du rôle de la Cuvette dans la biogéochimie du bassin au pas de temps journalier. A l'aide du modèle hydrologique SWAT (Soil and Water Assessment Tool) calibré en utilisant peu de données, et validé avec des produits de télédétection et des modèles biogéochimiques et hydrologiques, nous avons établi que la Cuvette Centrale est une source d'eau pour la cours d'eau principal durant l'étiage de 2000 à 2012. De plus, une analyse de la dynamique sédimentaire sur la période 2000-2012 a révélé que la Cuvette Centrale est capable de retenir plus de 23 mégatonnes de matériaux produits annuellement au sein de la Cuvette Centrale ou provenant de sources situées en amont. Les simulations du COD et du COP ont révélé que l'hydrologie et la pente sont les principaux facteurs de contrôles de ces flux. Les résultats ont révélé qu'entre 1,2 et 1,5 mégatonnes de COD sont produites dans la Cuvette Centrale avec 0,9 mégatonnes de COP retenues dans la Cuvette. À l'exutoire du bassin, des flux de 13,4 Mt an-1 pour le COD et de 2,2 Mt an-1 de COP ont été estimé, ce qui correspond à la gamme d'estimation des précédentes études.The Congo River basin (CRB) is the second largest drainage basin on Earth after the Amazon in terms of discharge and basin area. It also contains the second largest area of rainforest (1.8 million km2) that also hosts the single largest peatland deposit found (145,500 km2) in the Tropics. The Cuvette Centrale is the quarternary "sag" basin found at the center of this basin that receives flows from all the principal tributaries located in the right bank, left bank and the upper Congo River. While a few studies of the hydrology, sediments and organic matter biogeochemistry of the CRB have been made, there is a need to better constrain the lateral fluxes of material that pass through the Cuvette in order to best understand its role in the basin biogeochemistry at a daily time step. With the aid of the Soil and Water Assessment Tool (SWAT) hydrological model calibrated using scarce data, and validated with remote sensing products, biogeochemical and hydrological models, we have established the role of the Cuvette Centrale as a source of water to the main River during low flow periods for the 2000-2012 simulation period. Furthermore, an analysis of the sediment dynamics in the 2000-2012 period revealed that the Cuvette Centrale is capable of retaining over 23 megatons of material annually produced within the Cuvette Centrale and from upland sources. The models for DOC and POC revealed that hydrology and slope are primary controls on these fluxes. The results revealed that between 1.2 to 1.5 megatons of DOC is produced in the Cuvette Centrale with 0.9 megatons of POC retained in the Cuvette Centrale. At the basin outlet, a flux of 13.4 Mt yr-1 for DOC and 2.2 Mt yr-1 of POC was estimated, consistent with previous estimates

Simulating long-term food producing capacities in China using a Web-based land evaluation system

This dissertation presents a modeling approach to assess the long-term food producing capacities, and consequently food security, in China using a Web-based land evaluation system (WLES, http://weble.ugent.be). WLES implements a 3-step quantitative land evaluation model which evaluates the realistic yield of a field crop by considering the effects of (a) radiation and temperature regimes, (b) water stress, (c) limited soil fertility and (d) insufficient crop management. Homogeneous 5 km by 5 km grid datasets of climatic, soil, crop and management parameters were created. Food productions in 2030 and 2050 were simulated using production scenarios involving population growth, urbanization rate, cropland area, cropping intensity, management level and soil degradation. The model predicted that food crops may experience a 9.7% productivity loss by 2030 if the soil is degraded at the current rate (“business-as-usual” scenario, BAU); productivity loss will increase to an unbearable level of 36.7% by 2050, should the soil be twice more degraded than it is now (“double degradation” scenario, 2xSD). China's food producing capacity tends to decline in the long run if the general trend of soil degradation will not be reverted. China will be able to achieve a production of 430 million tons from food crops in 2030 and 410 million tons in 2050 under the BAU scenario, which are 11.5% and 15.5% lower than the 2005 level, respectively. In per capita terms, China will experience a food shortage of 9.8% in 2030 and 7.5% in 2050 even under the “zero-degradation” scenario (0xSD), compared to a 12.7% food surplus in 2005. Per capita food shortage in 2050 will be as high as 22.6% under the BAU scenario and 38.3% under the 2xSD scenario. The results suggest the present-day producing capacity (2005 level) will not be able to sustain the long-term needs under the current management level even if soil degradation is not becoming more limiting. The detrimental effect of soil degradation on food security is so evident that technical measures and policy levers must be activated today in order to avoid, or at least mitigate, the risks of food insecurity tomorrow

Putting Chinese natural knowledge to work in an eighteenth-century Swiss canton: the case of Dr Laurent Garcin

Symposium: S048 - Putting Chinese natural knowledge to work in the long eighteenth centuryThis paper takes as a case study the experience of the eighteenth-century Swiss physician, Laurent Garcin (1683-1752), with Chinese medical and pharmacological knowledge. A Neuchâtel bourgeois of Huguenot origin, who studied in Leiden with Hermann Boerhaave, Garcin spent nine years (1720-1729) in South and Southeast Asia as a surgeon in the service of the Dutch East India Company. Upon his return to Neuchâtel in 1739 he became primus inter pares in the small local community of physician-botanists, introducing them to the artificial sexual system of classification. He practiced medicine, incorporating treatments acquired during his travels. taught botany, collected rare plants for major botanical gardens, and contributed to the Journal Helvetique on a range of topics; he was elected a Fellow of the Royal Society of London, where two of his papers were read in translation and published in the Philosophical Transactions; one of these concerned the mangosteen (Garcinia mangostana), leading Linnaeus to name the genus Garcinia after Garcin. He was likewise consulted as an expert on the East Indies, exotic flora, and medicines, and contributed to important publications on these topics. During his time with the Dutch East India Company Garcin encountered Chinese medical practitioners whose work he evaluated favourably as being on a par with that of the Brahmin physicians, whom he particularly esteemed. Yet Garcin never went to China, basing his entire experience of Chinese medical practice on what he witnessed in the Chinese diaspora in Southeast Asia (the ‘East Indies’). This case demonstrates that there were myriad routes to Europeans developing an understanding of Chinese natural knowledge; the Chinese diaspora also afforded a valuable opportunity for comparisons of its knowledge and practice with other non-European bodies of medical and natural (e.g. pharmacological) knowledge.postprin