Wheat Production Systems and Global Climate Change

Urbanization affects the supply and spatial distribution of ecosystem services by changing the pattern of land use. Studying the spatial response of ecosystem services to urbanization can provide a scientific basis for urban planning and the establishment of ecological protection measures. Shannan Prefecture in the Tibet Autonomous Region is a typical plateau mountainous area with large elevation fluctuations and rich ecosystem types. It is an important ecological barrier in China and even the world. With ArcGIS software, this research used field survey data and statistical data, as well as the remote sensing data in 1990, 1995, 2000, 2005, 2010 and 2015, to analyze the land use pattern changes on different terrain gradients in Shannan, evaluate the spatial pattern of ecosystem service value (ESV) and its temporal and spatial changes on different terrain gradients, and finally analyze the response of ESV to urbanization. The results show that: a. In Shannan Prefecture, build-up lands were mainly distributed in the second and third terrain gradient. With the increase of terrain gradient, the area of farm land and forest land decreased, the area of grassland first in-creased and then decreased, and the area of unused land increased. b. The value of ecosystem services increases first and then decreases with the increase of terrain gradient, reaching the maximum in the third terrain gradient. c. During the study period, the value of ecosystem services showed a downward trend, with a significant decline at the second and third terrain gradient, which indicates that the urbanization has a negative impact on the value of ecosystem services. d. Through quantitative spatial analysis, it is found that urbanization is negatively related to the value of ecosystem services. Ecosystem service value and urbanization showing a high-low clustering effect account for a relatively large amount, more than 30%, mainly concentrated in the low terrain gradient in the southern part of Shannan; low-high clustering effect is mainly distributed in the second and third terrain gradient in the north, where the value of ecosystem services decreases with the increase of the urbanization degree, resulting in a significant agglomeration effect. Our research results offer a guidance for Shannan Prefecture to plan the land use, and optimize the land space and urbanization layout.

Tropical forests are biodiversity-rich but are dwindling at a rapid rate, not only in Southeast Asia but elsewhere also. The result is a loss of natural ecosystems, a reduction in carbon sequestration, and increasing global extinction of wild species, including iconic species. While several developments contribute to the destruction of tropical forests, the main threat comes from their clearing for the purpose of agricultural production, for example in the Amazon Basin for the expansion of the beef industry and soya bean cultivation. In Borneo and Sumatra, the principal threat to tropical forests comes from the expansion of oil palm (Elaeis guineensis) cultivation. This is expected to result in significant biodiversity loss and is a danger to the continuing existence of the iconic orangutan (Pongo pygmaeus). The preferred route for oil palm expansion is by the conversion of lowland tropical forests to plantations. Lowland tropical forests are the prime habitat of the orangutan and this species is especially at risk as a result of oil palm expansion. Two supply-side policies have been suggested in the literature as ways to reduce this expansion and reduce pressure on species such as the orangutan. It has been recommended that Imperata cylindrica grasslands be used to help accommodate future oil palm expansion in Borneo and Sumatra and that emphasis be placed on raising the yield of oil palms. It is hypothesised that this will reduce the demand for clearing tropical forest for the purpose of oil palm expansion. Both of these hypotheses are critically evaluated by means of economic analysis. It is concluded that neither of these policies are likely to be very effective in reducing the clearing of tropical forests in Borneo and Sumatra in order to grow oil palm.

QUANTIFYING PEATLAND CARBON DYNAMICS USING MECHANISTICALLY-BASED BIOGEOCHEMISTRY MODELS

Tropical forests play a crucial role in the global carbon cycle, accounting for one third of the global net primary productivity and containing about 25% of global vegetation biomass and soil carbon. This is particularly true for tropical forests in the Amazon region, as these comprise approximately 50% of the world's tropical forests. It is therefore important for us to understand and represent the processes that determine the fluxes and storage of carbon in these forests. In this study, we show that the implementation of phosphorus (P) cycle and P limitation in the version 1 of the Energy Exascale Earth System Model land model (ELM v1) improves simulated spatial pattern of wood productivity. The P‐enabled ELM v1 is able to capture the declining west‐to‐east gradient of productivity, consistent with field observations. We also show that by improving the representation of mortality processes using soils data, ELMv1 is able to reproduce the observed spatial pattern of above ground biomass. Our model simulations show that the consideration of P availability leads to a smaller carbon sink associated with CO2 fertilization effect and lower carbon emissions due to land use and land cover change. Our simulations suggest P limitation would significantly reduce the carbon sink associated with CO2 fertilization effects through the 21st century. We conclude that P cycle dynamics affect both sources and sinks of carbon in the Amazon region, and the effects of P limitation would become increasingly important as CO2 increases. Therefore, P limitation must be considered for projecting future carbon dynamics in tropical ecosystems.

Background: Currently, about 400 million hectares of tropical moist forests worldwide are designated production forests, about a quarter of which are managed by rural communities and indigenous peoples. There has been a gradual impoverishment of forest resources inside selectively logged forests in which the volume of timber extracted over the first cutting cycle was mostly from large, old trees that matured over a century or more and grew in the absence of strong anthropological pressures. In forests now being logged for a second and third time, that volume has not been reconstituted due in part to the lack of implementation of post-logging silvicultural treatments. This depletion of timber stocks renders the degraded forests prone to conversion to other land uses. Although it is essential to preserve undisturbed primary forests through the creation of protected areas, these areas alone will not be able to ensure the conservation of all species on a pan-tropical scale, for social, economic and political reasons. The conservation of tropical forests of tomorrow will mostly take place within human-modified (logged, domesticated) forests. In this context, silvicultural interventions are considered by many tropical foresters and forest ecologists as tools capable of effectively conserving tropical forest biodiversity and ecosystem services while stimulating forest production. This systematic review aims to assess past and current evidence of the impact of silviculture on tropical forests and to identify silvicultural practices appropriate for the current conditions in the forests and forestry sectors of the Congo Basin, Amazonia and Southeast Asia. Methods: This systematic review will undertake an extensive search of literature to assess the relative effectiveness of different silvicultural interventions on timber production and the conservation value of forests, and to determine whether there is a relationship between sustainability of timber harvesting and the maintenance/conservation of other ecosystem services and biodiversity in production forests. Data will be extracted for meta-analysis of at least sub-sets of the review questions. Findings are expected to help inform policy and develop evidence-based practice guidelines on silvicultural practices in tropical forests.

Evaluating the tropical forest carbon sink

Biodiversity is a term that covers all forms of life including genes, species of plants, animals, microorganisms and ecosystems and ecological processes. Economic use of biodiversity are still oriented towards large profits without regard to environmental damage. Explore the flora and fauna species can lead to excessive scarcity and extinction of species, so that natural resources can not support human welfare. Indonesia is one country that has the richest tropical forests in the world. Tropical forests as a storehouse of biodiversity is alleged to have shrunk by more than half, even agricultural land has been degraded, both in quality and quantity. In an effort to conserve biodiversity in Indonesia is practically encouraging the process of ecological succession to create a heterogeneous environment that provides opportunities of all species can evolve naturally. These efforts by establishing a nature reserve area, conservation of natural resources include: land, water, plants and animals, conservation germplasm, land and crop rotation, and the socialization role and function of biodiversity. Support of science and technology is needed as a tool in monitoring the sustainable utilization of biological resources, and policies and legal instruments. by way of identification and inventory of biological diversity in the distribution, presence, utilization, and management systems

Agricultural ecosystems deliver food, fibre, pharmaceuticals, bioenergy and are fundamental to human wellbeing. In Hungary main measures targeting the sustainable use of agricultural land in New Hungary Rural Development Programme (NHRDP) are: Agri-Environment Payments and payments to Less Favoured Areas. Based on theoretical assumptions, the delivery of different ecosystem services (e.g. soil fertility, pest control) may be typical of one product–product connection, but farms can deliver multiple services which by themselves are produced in non-separable packages. In this study we employ a transformation function with multiple outputs and inputs, representing the maximum output producing possibility from a given input and with given conditions using generalised linear regression. Given the limited options to implement the overall policy coherence of ecosystem conservation, the presented work contributes to knowledge of decisionmakers, whose need to take into account the heterogeneity of farms and corresponding ecosystem services on farm territory.

Conti, G., Enrico, L., Jaureguiberry, P., Cuchietti, A., Lipoma, M. L., Cabrol, D. 2018. The role of functional diversity in the provision of multiple ecosystem services: An empirical analysis in the dry Chaco of Cordoba, central Argentina. Ecosistemas 27(3):60-74.Doi.: 10.7818/ECOS.1491 The ecological relevance of the study of functional diversity (FD) as a driver of ecosystem processes and ecosystem services (ES) has been widely recognized, since it has been proven to be a useful approach to understand how plants respond to different naturalor anthropogenic changes and how they alter ecosystem processes determining the provision of key ES. However, it still lacks of empirical evidence that support this theoretical relationship in forest ecosystems under management. In this work, using as anexample the dry Chaco forest of central Argentina, we attempt to quantify the joint provision of multiple ecosystem services locally perceived and valued, evaluating and discussing the use of plant functional indices as proxies of the land use effect over the provision of ES. The results showed a reduction on regulating ES provision towards more intensively managed ecosystems. Within the components of the FD considered, mainly those associated with the variety and evenness on the distribution of the functional attributes and the structural attributes in the plant communities were more closely linked to the joint provision of multiple SEs in thesedry forests. Articulating forest management concepts with basic ecology approaches is an urgent step to move towards regional resource planning considering both, the intrinsic ecosystems properties and the differential interests of the social actors involved. This paper tries to be a first step to evaluate the methodological and conceptual approach of this discussion.

Forests play an important role in regulating climate change and maintaining carbon balance. To explore the carbon storage and carbon sequestration rate of national forest parks is of great significance for carbon sequestration capacity assessment and sustainable forest management. A process-based ecosystem model (CEVSA2 model) was used to simulate the spatial distribution of carbon density, carbon storage and carbon sequestration rate of 881 national forest parks in China during 1982-2017. The results showed that the average carbon density of national forest parks was 255.18 t C·hm-2, being higher than the average carbon density of forest ecosystem in China. In 2017, the total carbon storage of national forest parks increased to 3.56 Pg C, accounting for 11.0%-12.2% of the total carbon storage in national forest ecosystems. During 1982-2017, the average carbon sequestration rate of national forest parks reached 0.45 t C·hm-2·a-1, and the carbon sequestration rate of all national forest parks was above 0.30 t C·hm-2·a-1. National forest parks in the northeast and southwest of China had the highest total carbon storage. The national forest parks in northeast of China had the highest soil organic carbon sequestration rate, while those in eastern China and central southern China had the highest biomass carbon sequestration rate. The area of national forest parks accounted for 5.8% of the total forest area of China, playing an important role in forest carbon sink management of China. Accurate assessment of the growth status, carbon sequestration potential and carbon absorption characteristics of national forest parks could provide reference for the comprehensive assessment of ecosystem service of forest parks in China.

In the context of ecosystem conservation, tropical dry forests have received little or no attention compared with their next-door neighbors, the tropical rainforests. This lack of conservation effort in tropical dry forests is reflected in the fact that few national parks and biological reserves protect and preserve their natural richness, and there are only a handful of real biological research stations with a mandate to bridge the gap between ecology and conservation biology in these ecosystems. The funding and legal framework developed by international institutions and local governments has been implemented mainly to protect mature forest or pristine national parks located in regions other than dry forests. Several complex reasons may explain the lack of protection afforded to tropical dry forests. One of them is rooted in the romanticized vision that the tropics do not exist beyond the Amazon basin, a vision one finds every day in the scientific and nonscientific literature and in the electronic media. Another reason is the high economic value associated with goods and services that can be extracted from tropical dry forests, which contrasts with the relatively small economic value of tropical rainforests. This exploitation is furthered by local and national governments when they use dry forests not as the last frontier but as the first frontier of economic development. In the Caribbean, Mesoamérica, and northern South America, tropical dry forests are located in the most fertile zones for agroindustry and ecotourism development, and they contain a large proportion of the human population. Thus, only a small proportion of their total area is under some level of conservation. In Mesoamérica and in Venezuela, <1% of this ecologically, socially, and economically essential ecosystem is protected. Tropical dry forests are in dire need of integrated and multidisciplinary conservation research projects aimed at expanding traditional species- and niche-based research; increasing the biological and ecological knowledge base; and including human dimensions, which inevitably underlie how ecosystems change over time. Ecological studies on tropical dry forest succession, degradation, and restoration are few and most of them have been generated from a few sites. Tied to these ecological studies, conservation schemes are necessary that emphasize the tropical dry forest's contribution to environmental services and its value as a forest ecosystem, rather than as range or agricultural land. Rather than solely promoting the conservation of forest patches that will form isolated national parks or reserves, conservation approaches that pay landowners for environmental services must be implemented. Integrated land-management plans that complement the efforts of governments and the private sector must be enforced. The payment for ecosystem services carried out by the Costa Rican National Forest Financing Fund (FONAFIFO) is a good example of the feasibility of such initiatives. Furthermore, efforts toward conservation of tropical dry forests must also address the need to consider ecosystem services provided by mature ecosystems and areas at various successional stages within and outside public lands. In fact, secondary dry forests may be the dominant landscape in the forthcoming years, as land abandoned by local farmers recovers. In Costa Rica alone, almost 50% of the Guanacaste Peninsula is covered by deciduous secondary forests. Payment for ecosystem services in the tropics, however, requires funds that are largely unavailable. For a payment strategy to succeed, it is critical that national environmental authorities display the necessary political will to invest resources and develop the required regulatory framework. But it is also fundamental that the governments of developed countries, as well as multinational agencies, international conservation organizations, and private donors, look beyond humid tropical ecosystems and expand their portfolio of conservation investments toward tropical dry forests. We could uncover a wealth of valuable information by consciously promoting land-use practices that minimize the amount of stress and land-cover conversion carried out around dry forested areas. Such an approach, combined with educational programs that promote bioliteracy in local schools and community decision-making organizations, would highlight the economic and ecological value of the tropical dry forest as an ecosystem. This approach would further uncover the contributions of tropical dry forests to society, a role that far surpasses their value for anything else. Such an approach, however, can only be explored and demonstrated by further investigating how to successfully integrate alternative land uses into the management of dry forest ecosystems. With an increasing population, a long history of land-use change, and free-trade agreements that encourage large agroindustry developments (e.g., extensive cattle ranching, and watermelon and sugarcane plantations in Mexico and Costa Rica) and a significant increase of their exploitation for ecotourism, the future of tropical dry forests, at least in the Caribbean, Mesoamérica, and northern South America, is of great concern. Land-use choices that are made around these forests will continue to influence their rapid degradation regardless of how many studies we conduct to find out what it is needed to promote their conservation. The remaining dry forests, which include numerous rare and endemic species, offer a unique opportunity to learn more about types of interactions between species and the resulting ecological processes. This information, in turn, would be of tremendous help to policy makers responsible for defining sustainable development policies aimed at benefiting threatened species (e.g., Scarlet Macaw [Ara macao], Yellow-shouldered Parrot [Amazona barbadensis], jaguar [Panthera onca], Baird's tapir [Tapirus bairdii], great false vampire bat [Vampyrum spectrum)], guayacán [Guaiacum sanctum]). More studies are also needed to understand the ecological succession of disturbed tropical dry forest left in fragments and its contribution as a stepping stone between fragments and the forest. Because small populations or communities may be recovering in regenerating fragments, these areas should not be considered waste land but rather important elements that connect protected areas. Furthermore, the immediate sharing of this ecological knowledge with local communities would help convince them to invest in the longevity of this ecosystem and to promote the recovery of degraded areas. An additional and highly contentious topic is the conflict between increasing human demands on water resources and the varying water needs of the differing components of the tropical forest matrix. The matrix is composed of deciduous tropical forest, mangroves, wetlands, savannas, and riparian forests. Such biological wealth is currently endangered by human water demands that depend on this limited resource. Increasing and uncontrolled use of limited water resources for irrigation, human consumption, and tourism—a phenomenon that translates into new dams, deviation of rivers, and the use of river discharge during low-flow seasons—jeopardizes the future of tropical dry forest biodiversity. We believe that research and conservation in tropical dry forests must generate conservation models that are promoted with the same fervor as those designed for humid forests. For example, phenological aspects (e.g., leaf shed, flowering, fruiting) have been especially neglected in large-scale studies, downplaying the fact that part of the uniqueness of this ecosystem is its phenological responses to changing environmental conditions. These "preadaptations" may be essential as global-change-coping mechanisms by tropical biotas. Many questions have yet to be answered. But if we are to understand the phenological responses of individual species and the drivers and effects of degradation and land exploitation on the phenological cycles of the ecosystem at a larger scale—including the organisms that depend on them—more comprehensive conservation efforts are necessary. These efforts must be linked to adequate funding levels that promote comprehensive in situ and comparative studies among dry forest ecosystems across the Americas.

Modern intensive agricultural practices characteristic of Western Europe and North America, such as high usage of agro-chemicals, are cited as key drivers of biodiversity declines. Declines in biodiversity are likely to impact on a number of natural processes termed ‘ecosystem services’, which include pollination and pest control that play an important role in agricultural production. Because of the negative effects of intensive agricultural practices, there has been a search for alternative systems of production. One approach is ecological intensification, where ecosystem services are maximised in agriculture as a way to offset anthropogenic inputs that can damage the wider environment. Key to the success of ecological intensification is gaining a mechanistic understanding of how biodiversity supports the functioning of ecosystem services, so management can be targeted to maximise service delivery. In order to ensure that food production is sustainable in the face of constantly changing environments it is also important to understand how biodiversity responds to stressors, such as insecticide use. This thesis focuses on using invertebrate species morphological and behavioural characteristics—referred to collectively as traits—to gain a mechanistic understanding of how different components of biodiversity support the functioning and resilience of pollination and pest control ecosystem services. Results highlight that trait approaches provide higher accuracy in predicting the functioning and resilience of natural pest control and pollination, than measures such as species richness. I also highlight that common environmental stressors such as insecticides and extreme heat have the potential to limit pest control and pollination ecosystem services, respectively. My results broadly demonstrate that utilising invertebrate species behavioural and morphological traits are beneficial in understanding the mechanisms driving pollination and pest control ecosystem services.

We need to move towards more sustainable farming methods that maximise yields whilst protecting the environment. One approach that would achieve this goal is ecological intensification, which seeks to manage the biodiversity and ecological processes underpinning agricultural production so that damaging farming practices can be replaced or reduced. Forb-rich arable field margins have been shown to benefit flower-visiting insects such as wild bees, and recent evidence suggests that they can also enhance the levels of pollination and pest control in adjacent crop fields. They may also promote a suite of additional ecosystem services of societal and agronomic importance, but this has yet to be established. Furthermore, the ability of forb-rich field margins to deliver multiple benefits (i.e. ecosystem multifunctionality), including pest control and pollination, is likely to be contingent on a range of local and landscape factors. Using a range of pre-existing field margin plots (n = 98) distributed across 16 arable farms in central eastern England, this study first sought to examine whether high quality forb-rich field margins promote ecosystem multifunctionality more effectively than low quality forb-poor field margins. This involved measuring a range ecosystem services within and adjacent to field margin plots, including pest control, pollination, soil carbon storage, flood alleviation, the abundance of invertebrate ecosystem service providers and the amount of invertebrate biodiversity. Secondly, it established whether arable field margins provide adequate foraging resources for flower-visiting insects. And thirdly, it determined the local and landscape factors (including margin quality) that best promote ecosystem service provision and invertebrate biodiversity within agro-ecosystems. The findings indicated that quality was the most important determinant of ecosystem multifunctionality within arable field margins, as high quality margins supported significantly greater levels of pest control, pollination, flood alleviation and invertebrate biodiversity. However, a range of additional local and landscape management prescriptions further enhanced the multifunctionality of arable field margins, such as the level of vehicle traffic margins receive, vegetation height, landscape complexity and the amount of floral resources provided by the adjacent hedgerow. Despite the multiple benefits of high quality field margins, they were also found to enhance invertebrate crop pests. This may reduce the willingness of farmers to adopt forb-rich habitats on their land. Finally, the present study highlights that more consideration should be given to the forb species included within field margin seed mixes, as certain species were found to promote agronomically damaging crop pests, whereas other species not currently included in field margin seed mixes were extremely attractive to several important flower-visiting taxa or flowered during spring; a period in which field margins are floristically poor. This thesis clearly demonstrates that forb-rich field margins provide multiple agronomic, societal and biodiversity benefits, and outlines the important drivers of ecosystem multifunctionality. As such, it provides farmers and landowners with a clear set of management guidelines for promoting biodiversity and ecosystem services within arable field margins.

Summary Land-surface models are important tools for simulation of the past, present, and future capacity of terrestrial ecosystems to absorb anthropogenic CO2 emissions. However, fluvial carbon (C) transfers are presently neglected in these models. Using the Amazon basin as a case study, we show that this negligence leads to significant underestimation of the net uptake of atmospheric C while terrestrial C storage changes are overestimated. These biases arise from the fact that C—in reality, leached from soils and exported through the river network—is instead represented as partly being respired and partly being stored in soils. Moreover, these biases scale mainly to the fluvial C export to the coast, despite aquatic CO2 emission to the atmosphere being the major pathway of riverine C exports. We further show that fluvial C transfers may change significantly in response to changes in either hydrology or in atmospheric C uptake by vegetation.

Savannah biomes cover a fifth of Earth’s surface, harbour many of the world’s most iconic&#13;\nspecies and most of its livestock and rangeland, while sustaining the livelihoods of an&#13;\nimportant proportion of its human population. They provide essential ecosystem services and&#13;\nfunctions, ranging from forest, grazing and water resources, to global climate regulation and&#13;\ncarbon sequestration. However, savannahs are highly sensitive to human activities and climate&#13;\nchange. Across sub-Saharan Africa, climatic shifts, destructive wars and increasing&#13;\nanthropogenic disturbances in the form of agricultural intensification and urbanization, have&#13;\nresulted in widespread land degradation and loss of ecosystem services. Yet, these threatened&#13;\necosystems are some of the least studied or protected, and hence should be given high&#13;\nconservation priority. Importantly, the scale of land degradation has not been fully explored,&#13;\nthereby comprising an important knowledge gap in our understanding of ecosystem services&#13;\nand processes, and effectively impeding conservation and management of these biodiversity&#13;\nhotspots.&#13;\nThe primary drivers of land degradation include deforestation, triggered by the increasing&#13;\nneed for urban and arable land, and concurrently, shrub encroachment, a process in which the&#13;\nherbaceous layer, a defining characteristic of savannahs, is replaced with hardy shrubs. These&#13;\nprocesses have significant repercussions on ecosystem service provision, both locally and&#13;\nglobally, although the extents, drivers and impacts of either remain poorly quantified and&#13;\nunderstood. Additionally, regional aridification anticipated under climate change, will lead to&#13;\nimportant shifts in vegetation composition, amplified warming and reduced carbon&#13;\nsequestration. Together with a growing human population, these processes are expected to&#13;\ncompound the risk of land degradation, thus further impacting key ecosystem services.&#13;\nNamibia is undergoing significant environmental and socio-economic changes. The most&#13;\npervasive change processes affecting its savannahs are deforestation, degradation and shrub&#13;\nencroachment. Yet, the extent and drivers of such change processes are not comprehensively&#13;\nquantified, nor are the implications for rural livelihoods, sustainable land management, the&#13;\ncarbon cycle, climate and conservation fully explored. This is partly due to the complexities&#13;\nof mapping vegetation changes with satellite data in savannahs. They are naturally spatially&#13;\nand temporally variable owing to erratic rainfall, divergent plant functional type phenologies&#13;\nand extensive anthropogenic impacts such as fire and grazing. Accordingly, this thesis aims to&#13;\n(i) quantify distinct vegetation change processes across Namibia, and (ii) develop&#13;\nmethodologies to overcome limitations inherent in savannah mapping. Multi-sensor satellite&#13;\ndata spanning a range of spatial, temporal and spectral resolutions are integrated with field&#13;\ndatasets to achieve these aims, which are addressed in four journal articles.&#13;\nChapters 1 and 2 are introductory. Chapter 3 exploits the Landsat archive to track changes in&#13;\nland cover classes over five decades throughout the Namibian Kalahari woodlands. The&#13;\napproach addresses issues implicit in change detection of savannahs by capturing the distinct&#13;\nphenological phases of woody vegetation and integrating multi-sensor, multi-source data.&#13;\nVegetation extent was found to have decreased due to urbanization and small-scale arable&#13;\nfarming. An assessment of the limitations leads to Chapter 4, which elaborates on the&#13;\nprevious chapter by quantifying aboveground biomass changes associated with deforestation&#13;\nand shrub encroachment. The approach centres on fusing multiple satellite datasets, each&#13;\nacting as a proxy for distinct vegetation properties, with calibration/validation data consisting&#13;\nof concurrent field and LiDAR measurements. Biomass losses predominate, demonstrating&#13;\nthe contribution of land management to ecosystem carbon changes.&#13;\nTo identify whether biomass is declining across the country, Chapter 5 focuses on regional,&#13;\nmoderate spatial resolution time-series analyses. Phenological metrics extracted from MODIS&#13;\ndata are used to model observed fractional woody vegetation cover, a proxy for biomass.&#13;\nTrends in modelled fractional woody cover are then evaluated in relation to the predominant&#13;\nland-uses and precipitation. Negative trends slightly outweighed positive trends, with&#13;\ndecreases arising largely in protected, urban and communal areas. Since precipitation is a&#13;\nfundamental control on vegetation, Chapter 6 investigates its relation to NDVI, by assessing&#13;\nto what extent observed trends in vegetation cover are driven by rainfall. NDVI is modelled as&#13;\na function of precipitation, with residuals assumed to describe the fraction of NDVI not&#13;\nexplained by rainfall. Mean annual rainfall and rainfall amplitude show a positive trend,&#13;\nalthough extensive “greening” is unrelated to rainfall. NDVI amplitude, used as a proxy for&#13;\nvegetation density, indicates a widespread shift to a denser condition.&#13;\nIn Chapter 7, trend analysis is applied to a Landsat time-series to overcome spatial and&#13;\ntemporal limitations characteristic of the previous approaches. Results, together with those of&#13;\nthe previous chapters, are synthesized and a synopsis of the main findings is presented.&#13;\nVegetation loss is predominantly caused by demand for urban and arable land. Greening&#13;\ntrends are attributed to shrub encroachment and to a lesser extent conservation laws, agroforestry&#13;\nand rangeland management, with precipitation presenting little influence. Despite&#13;\nprevalent greening, degradation processes associated with shrub encroachment, including soil&#13;\nerosion, are likely to be widespread. Deforestation occurs locally while shrub encroachment&#13;\noccurs regionally. This thesis successfully integrates multi-source data to map, measure and&#13;\nmonitor distinct change processes across scales.