Land, Volume 2, Issue 3 (September 2013) – 11 articles , Pages 304-533

The paper analyzes land use changes, notably cropland expansion, in SE-Niger from the mid-1980s to 2011. It scrutinizes land use trajectories and investigates how cultivation shifts between dune landscapes and valleys (bas-fonds) in response to climate, population pressure, and sociocultural opportunities, combining lenses rooted in land change science and the notions of double exposure and human-environmental timelines. Specifically, the interest is directed towards exploring the value of different methods of land use data harvesting. The importance of cropland expansion is assessed in two ways: by interpreting Landsat satellite images and by interviewing local people to obtain qualitative descriptions. The results demonstrate a glaring discrepancy between the assessed land use trends derived from these two data sources. Issues such as important developments in landscape priorities, allocation of cropland between dunes and valleys, possible land saturation, and adaptation to climate change or globalization are portrayed very differently. It is concluded that critical attention to data reliability is crucial to avoid misleading narratives in land change science, especially in places covered by sparse data. Full article

The island of La Gonave lies northwest of Port-au-Prince and is representative of the subsistence Haitian lifestyle. Little is known about the land cover changes and conversion rates on La Gonave. Using Landsat images from 1990 to 2010, this research investigates landscape dynamics through image classification, change detection, and landscape pattern analysis. Five land cover classes were considered: Agriculture, Forest/Dense Vegetation (DV), Shrub, Barren/Eroded, and Nonforested Wetlands. Overall image classification accuracy was 87%. Results of land cover change analysis show that all major land cover types experienced substantial changes from 1990 to 2010. The area percent change was −39.7, −22.7, 87.4, and −7.0 for Agriculture, Forest/Dense Vegetation, Shrub, and Barren/Eroded. Landscape pattern analysis illustrated the encroachment of Shrub cover in core Forest/DV patches and the decline of Agricultural patch integrity. Agricultural abandonment, deforestation, and forest regrowth combined to generate a dynamic island landscape, resulting in higher levels of land cover fragmentation. Full article

Pollination is a key ecosystem service as many crops but in particular, fruits and vegetables are partially dependent on pollinating insects to produce food for human consumption. Here we assessed how pollination services are delivered at the European scale. We used this assessment to estimate the relative contribution of wild pollinators to crop production. We developed an index of relative pollination potential, which is defined as the relative potential or relative capacity of ecosystems to support crop pollination. The model for relative pollination potential is based on the assumption that different habitats, but in particular forest edges, grasslands rich in flowers and riparian areas, offer suitable sites for wild pollinator insects. Using data of the foraging range of wild bees with short flight distances, we linked relative pollination potential to regional statistics of crop production. At aggregated EU level, the absence of insect pollination would result in a reduction of between 25% and 32% of the total production of crops which are partially dependent on insect pollination, depending on the data source used for the assessment. This production deficit decreases to 2.5% if only the relative pollination potential of a single guild of pollinators is considered. A strength of our approach is the spatially-explicit link between land cover based relative pollination potential and crop yield which enables a general assessment of the benefits that are derived from pollination services in Europe while providing insight where pollination gaps in the landscape occur. Full article

Landscape changes and the processes driving them have been a critical component in both research and management efforts of savanna systems. These dynamics impact human populations, wildlife, carbon storage, and general spatio-temporal dynamism in response to both anthropomorphic and climatic shifts. Both biophysical and human agents of change can be identified by isolating their respective spatial, temporal, and organizational contingencies. However, we argue here that a significant portion of savanna research has either considered humans as exogenous (e.g., via enacting regional or broader policies) or somewhat spatio-temporally removed from the system (e.g., as in many protected areas with limited current human habitation). Examples from African savanna research and particularly those systems of southern Africa are thus reviewed and used to model a stylized or prototypical savanna system and contingencies. Such an approach allows for a richer socio-temporal integration of theories and data on past biophysical and human histories to facilitate an improved framework for understanding savanna systems and their complex contingencies as socio-ecological landscapes. Full article

A one year field trial was carried out on three adjacent unfertilised plots; an 18 year old grassland, a 14 year old established Miscanthus crop, and a 7 month old newly planted Miscanthus crop. Measurements of N₂O, soil temperature, water filled pore space (WFPS), and inorganic nitrogen concentrations, were made every one to two weeks. Soil temperature, WFPS and NO₃⁻ and NH₄⁺ concentrations were all found to be significantly affected by land use. Temporal crop effects were also observed in soil inorganic nitrogen dynamics, due in part to C₄ litter incorporation into the soil under Miscanthus. Nonetheless, soil N₂O fluxes were not significantly affected by land use. Cumulative yearly N₂O fluxes were relatively low, 216 ± 163, 613 ± 294, and 377 ± 132 g·N·ha⁻¹·yr⁻¹ from the grassland, newly planted Miscanthus, and established Miscanthus plots respectively, and fell within the range commonly observed for unfertilised grasslands dominated by perennial ryegrass (Lolium perenne). Higher mean cumulative fluxes were measured in the newly planted Miscanthus, which may be linked to a possible unobserved increase immediately after establishment. However, these differences were not statistically significant. Based on the results of this experiment, land-use change from grassland to Miscanthus will have a neutral impact on medium to long-term N₂O emissions. Full article

In Central Java, in addition to the traditional view of urban transition as an aspect of urban industrialization, rural industrialization based on small- to medium-sized enterprises has become a concern, at least since the Indonesian economic crisis in 1997. Combinations of typical urban and rural activities have resulted in certain features of rural-urban transition as the urban population has continued to increase notably. The intention of this paper is to examine how rural-urban transition characterizes the industrialization of Central Java. Multivariate cluster analysis is applied to create a typology, with the district as the unit of analysis, to better understand the transition phenomenon in terms of the population and economic structure. The cluster solution shows that rural-urban transition occurs on at least two different paths. The first path could be described as industrialization from above, in which the transition takes place as a part of the urban growth process. The second path could be described as industrialization from below, in which rapid industrialization occurs far from the highest hierarchy of the urban center. Full article

Targeted illegal harvesting of hardwood in the woodland of Namibia’s Kavango region threatens forest stands. In a transforming setting, where wood is increasingly traded through value chains on a globalized market, local harvesters have complex incentives but also a crucially important position. Sustainability largely depends on their choices. Such choices are being influenced by awareness campaigns and decentralized forest management, which are being lauded and supported. Having produced an ethnographic awareness film (AF) on the problem of logging and the opportunities for community forests (CF) to reduce extractions while raising community income, we approach the influence of the instruments of film and community forests on forest-users’ real life choices with an economic public goods game. We compare villages that have experienced influences to a differing degree. We find more extraction in AF and no effect for CF at village level. Instead, the extractive impact of certain experimental and free riding personality types, whose strategies remain stable across the experiment, is equally distributed among villages. We discuss methodological implications and the fact that in a situation of ecological and socio-economic challenges certain players use game and real life opportunities to decouple individual choice from problem awareness and the social control-setting. Full article

The Siwalik Hills is one of the most fragile and vulnerable ecosystems in the Nepalese Himalaya where soil erosion and land degradation issues are fundamental. There is very limited knowledge on soil erosion processes and rates in this region in comparison to other regions of the Himalaya. The aims of the present paper are to document, measure and interpret key soil erosion processes and provide an estimate of erosion rates in the Khajuri Stream catchment located in the eastern Siwalik Hills. We used erosion pins to monitor sheet erosion, gully erosion, landslides and stream bank erosion over the period from 2002 to 2004. Sheet erosion from forest and shrubs generally varied from 0.8–1.2 mm·yr⁻¹ with a mean erosion rate of ~16 t·ha⁻¹·yr⁻¹. Gully erosion rate was estimated to be ~14 t·ha⁻¹·yr⁻¹. Erosion from landslides was significantly higher which was estimated to be ~26 t·ha⁻¹·yr⁻¹. Stream bank erosion varied widely from 0.03 to 0.25 m·yr⁻¹ with a mean erosion rate of ~8 t·ha⁻¹·yr⁻¹. Based on these rates, it was estimated that ~21,000 m³ (64 t·ha⁻¹) of sediment was being eroded within the catchment annually. In comparison to the erosion rates of other regions of the Himalaya these rates are significantly higher. Full article

Intensity Analysis has become popular as a top-down hierarchical accounting framework to analyze differences among categories, such as changes in land categories over time. Some aspects of interpretation are straightforward, while other aspects require deeper thought. This article explains how to interpret Intensity Analysis with respect to four concepts. First, we illustrate how to analyze whether error could account for non-uniform changes. Second, we explore two types of the large dormant category phenomenon. Third, we show how results can be sensitive to the selection of the domain. Fourth, we explain how Intensity Analysis’ symmetric top-down hierarchy influences interpretation with respect to temporal processes, for which changes during a time interval influence the sizes of the categories at the final time, but not at the initial time. We illustrate these concepts by applying Intensity Analysis to changes during one time interval (2000–2004) in a part of Central Kalimantan for the land categories Forest, Bare and Grass. Full article

Agricultural expansion has eliminated a high proportion of native land cover and severely degraded remaining native vegetation. Managers must determine where degradation is severe enough to merit restoration action, and what action, if any, is necessary. We report on grassland degraded by multiple factors, including grazing, soil disturbance, and exotic plant species introduced in response to agriculture management. We use a multivariate method to categorize plant communities by degradation state based on floristic and biophysical degradation associated with historical land use. The variables we associate with degradation include abundance of the invasive cool-season grass, tall fescue (Schedonorus phoenix (Scop.) Holub); soil organic carbon (SOC); and heavy livestock grazing. Using a series of multivariate analyses (ordination, hierarchical clustering, and multiple regression), we identify patterns in plant community composition and describe floristic degradation states. We found vegetation states to be described largely by vegetation composition associated primarily with tall fescue and secondarily by severe grazing, but not soil organic carbon. Categorizing grasslands by vegetation states helps managers efficiently apply restoration inputs that optimize ecosystem response, so we discuss potential restoration pathways in a state-and-transition model. Reducing stocking rate on grassland where grazing is actively practiced is an important first step that might be sufficient for restoring grassland with high native species richness and minimal degradation from invasive plants. More severe degradation likely requires multiple approaches to reverse degradation. Of these, we recommend restoration of ecological processes and disturbance regimes such as fire and grazing. We suggest old-field grasslands in North America, which are similar to European semi-natural grassland in composition and function, deserve more attention by conservation biologists. Full article

Urban areas are directly or indirectly responsible for the majority of anthropogenic CO₂ emissions. In this study, we characterize observed atmospheric CO₂ mixing ratios and estimated CO₂ fluxes at three sites across an urban-to-rural gradient in Boston, MA, USA. CO₂ is a well-mixed greenhouse gas, but we found significant differences across this gradient in how, where, and when it was exchanged. Total anthropogenic emissions were estimated from an emissions inventory and ranged from 1.5 to 37.3 mg·C·ha⁻¹·yr⁻¹ between rural Harvard Forest and urban Boston. Despite this large increase in anthropogenic emissions, the mean annual difference in atmospheric CO₂ between sites was approximately 5% (20.6 ± 0.4 ppm). The influence of vegetation was also visible across the gradient. Green-up occurred near day of year 126, 136, and 141 in Boston, Worcester and Harvard Forest, respectively, highlighting differences in growing season length. In Boston, gross primary production—estimated by scaling productivity by canopy cover—was ~75% lower than at Harvard Forest, yet still constituted a significant local flux of 3.8 mg·C·ha⁻¹·yr⁻¹. In order to reduce greenhouse gas emissions, we must improve our understanding of the space-time variations and underlying drivers of urban carbon fluxes. Full article