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Spatio-temporal landscape transformations in Southern Chile and its implications on ecosystem services supply and beneficiaries

dc.contributor.advisorLautenbach, Sven
dc.contributor.authorLocher Krause, Karla Estela
dc.description.abstractHuman-induced global change has driven drastic modifications of ecosystems that could lead to unexpected and unprecedented transformations in the present and future decades. Current systems modifications increased the need for more comprehensive and evenly distributed databases across ecosystems and spatio-temporal scales. Moreover, base knowledge that allows a better understanding of land-use trajectories and their impacts on the supply of multiple ecosystem services and thus supports the development of highly relevant guidelines for improving landscape management decisions. Hotspots of biodiversity are biogeographical areas identified as biodiversity reservoirs that have been recognized as under threat due to human impacts. These biodiversity reservoirs require further investigation to prevent the deterioration of their ecological functions. Hence, this dissertation aims to understand the impacts and effects of human activities in a biodiversity hotspot area, the Valdivian temperate rainforest by expanding the temporal resolution of land cover data and ecosystem services assessments. The Valdivian temperate rainforest is located in Southern Chile, Northern Chilean Patagonia (73°20’ W-39°25’ S - 71°59’ W-41° 14’ S). The area has been identified as a biodiversity hotspot due to a high number of endemic species (90% at the species level and 34% at the genus level for woody species), and its intense level of human appropriation. This dissertation addresses the following three objectives: 1) Uncovering landscape transformation by expanding the temporal resolution of analyses of landscape dynamics in a biodiversity hotspot area; 2) Understanding the spatio-temporal dynamics of the supply of multiple ecosystems services at the landscape scale; 3) Assessing the contribution of an integrated landscape management strategy to reconnect fragmented ecosystems, on ecosystem services supply and its beneficiaries.
The integration of different types of biophysical and socioeconomic data, as well as methodologies from diverse fields such as remote sensing, ecological modeling, and landscape ecology, were included to answer the main questions of the dissertation. A higher temporal resolution of land-cover dynamics was investigated by using all Landsat scenes available for the study area from 1985 to 2011 (7 periods) and a spatial resolution of 30 meters. An automatic classification with random forest and local ground information allowed to uncover the dynamic of land-cover composition and configuration in the area. Based on this analysis and additional biophysical and socioeconomic data, the trajectory of the ecosystem services supply in the area was revealed at the same temporal scale (7 periods) but with a spatial differentiation between the main four geomorphological units. All these datasets and the methodological procedure of this thesis resulted in the development of landscape planning recommendations that were assessed in the final chapter of this dissertation. The assessed landscape planning strategy builds on the protection of structural connectivity areas (SCA) —defined as the integration of linear (riparian corridors) and patchy (national conservation units) landscape elements— and its contribution to ecosystem services supply as well as its beneficiaries across the landscape.
Results from the land-cover dynamics analysis revealed a highly dynamic and transformed landscape influenced by processes such as clear-cuts of exotic forest plantations, regrowth of secondary forest, afforestation with exotic tree species, together with deforestation and fragmentation of native forest. These modifications impacted both the composition and configuration of the landscape. Areas with exotic forest plantation drastically increase especially from 1985 until 1999 with the highest net increase of 706% from 1985 until 2011. Old-growth forests showed a continuous decrease over time, with the highest deforestation rate of 1.2% - net loss - between 1985 and 1999, this deforestation rate tends to slow down in the last study period (2010-2011). Moreover, the fragmentation of old-growth forest rose especially between 1985-1999 with the decline of patch size and an increase of the total edge length. Secondary forest showed an increase over time but with small and fragmented patches across the landscape. In the case of the ecosystem services supply, the different geomorphological units revealed a diverse pattern with higher regulation services in the Andes and Coastal range in comparison with provisioning services mostly allocated in the Central Valley. The ecosystem services supply trajectory uncovered a decrease of carbon stocks in both mountain ranges as well as an increase in the Central Valley. Regulating services such as sediment and phosphorous retention showed irregular trends which reflected the diverse management strategies used in the area in addition to the low compliance of stream buffer protection, that highlighted the importance of protecting riparian areas. Cultural ecosystem services also declined, for example, the case of aesthetic value that decreased (degree of naturalness) over time and across the study area. In the case of recreational services, even though there is an increase in the service during the study period, these areas are isolated with low or limited access, and a low type of ecosystems represented. Concerning the recommended landscape planning strategy (SCA) assessed in the last chapter, the results reported a positive contribution —maintaining and enhancing— not only to ecosystem services supply but also to the conservation in the area. The assessment revealed the high potential of SCA as a conservation strategy by reconnecting this fragmented landscape and protecting vulnerable areas (riparian corridors); due to the high amount of services that they supply (more than 60%), with an also a higher density of beneficiaries, even when SCA only account for 40% of the total study area.
The results of this dissertation confirm the relevance of integrated research by combining various techniques, disciplines and the consideration of different spatio-temporal scales to achieve better awareness of the functioning of socio-ecological systems by using the ecosystem services concept as a framework. Furthermore, the results highlight the necessity of an expanded temporal resolution in land-cover and ecosystem service assessments to provide more targeted and grounded recommendations for landscape planning.
dc.rightsIn Copyright
dc.subject.ddc500 Naturwissenschaften
dc.titleSpatio-temporal landscape transformations in Southern Chile and its implications on ecosystem services supply and beneficiaries
dc.typeDissertation oder Habilitation
dc.publisher.nameUniversitäts- und Landesbibliothek Bonn
ulbbnediss.affiliation.nameRheinische Friedrich-Wilhelms-Universität Bonn
ulbbnediss.instituteLandwirtschaftliche Fakultät : Institut für Geodäsie und Geoinformation (IGG)
ulbbnediss.fakultaetLandwirtschaftliche Fakultät
dc.contributor.coRefereeVolk, Martin

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