Browsing by Author "Lannas, Kathryn S. M."

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A Contextual Analysis of Land-Use and Vegetation Changes in Two Wooded Pastures in the Swiss Jura Mountains
(2013) Chételat, Joël; Kalbermatten, Michael; Lannas, Kathryn S. M.; Spiegelberger, Thomas; Wettstein, Jean-Bruno; Gillet, François; Peringer, Alexander; Buttler, Alexandre
"This study examines the effects of land-use policies and natural events on the evolution of two wooded pastures in the Jura Mountains in Switzerland between 1934 and 2000. The socioeconomic context and the local conditions were seen as major driving forces influencing land management practices which in turn redefined land-use policies. We studied the dynamics of the Jura Mountains’ wooded pastures, combining a thorough knowledge of the historic context with aerial image analysis. Besides pointing out general milestones in the evolution of Swiss land policy, we compiled chronicles on the management for both study sites on the basis of archives and interviews. Aerial images taken at time intervals of approximately 15 years were chosen to identify land-cover changes. The method used to analyze them relied on a structural classification of phytocoenoses, thus allowing the determination of four categories of tree-cover densities ranging from unwooded pastures to ungrazed forest. We reported overall aerial changes for each tree density class as well as spatial transitions from one category to another. The combination of spatial statistics with qualitative data depicting the evolution of the historic context gives a better understanding of the land-use changes and their rationale. The most important changes in tree density occurred during World War II and resulted in a more open landscape. The intensive use of wooded pastures during the war was the consequence of a high demand for wood and food resources. Postwar protectionist regulations, agricultural subsidies, and technical improvements maintained considerable pressure on wooded pastures. Storms and drought episodes further exacerbated this process in some areas. The trend then reversed from the 1970s onwards because of the limitations put on milk production and the falling price of wood. This resulted in a more extensive use of pastures, leading to tree encroachment. However, remote sites were more impacted than pastures closer to inhabited areas, which exhibited a trend towards more segregation between grassland and densely wooded pastures. With both extensification and segregation of land use, the complex vegetation mosaic and the landscape diversity that characterize wooded pastures are threatened but still offer good economic opportunities that call for differentiated management strategies."
Valuing the Provisioning Services of Wetlands: Contrasting a Rural Wetland in Lesotho with a Peri-Urban Wetland in South Africa
(2009) Lannas, Kathryn S. M.; Turpie, Jane
"Given that few studies have valued the provisioning services of temperate southern African wetlands, research on this topic was undertaken in a remote rural wetland, Letseng-la-Letsie, in Lesotho and a peri-urban wetland in Mfuleni, Cape Town. The objectives were to quantify incomes from wetland resources, assess the relative dependency of communities on wetland provisioning services, and estimate the total provisioning value of the wetlands. Data were collected from informal interviews and structured household surveys. Despite the different settings, both wetlands were used mainly for grazing livestock. The estimated total value added during 2007 from grazing was U.S. $180,078 for Letseng-la-Letsie and U.S. $540,286 for Mfuleni. Letseng-la-Letsie and Mfuleni were also used for hunting, and Mfuleni was partially cultivated. Even though the local wetlands were easier to access from Mfuleni, only 13% of households used them, compared with 65% in Letseng-la-Letsie. However, the households around Letsengla-Letsie derived less of their income (6%) from the wetlands, compared with 82% in Mfuleni. This reflects the more specialized livelihood strategies in the urban compared with the rural setting, in which riskspreading household production strategies were more prevalent. The loss of the wetland in Letseng-la-Letsie would therefore potentially affect more people but have less of an effect on the finances of individual households than in Mfuleni. It is estimated that U.S. $220/ha and U.S.$1765/ha is derived annually from wetland provisioning services in Letseng-la-Letsie and Mfuleni, respectively. A standard protocol is needed for valuing wetlands in southern Africa."