Die chronologische Liste zeigt aktuelle Veröffentlichungen aus dem Forschungsbetrieb der Hochschule Weihenstephan-Triesdorf. Zuständig ist das Zentrum für Forschung und Wissenstransfer (ZFW).
Dr. Birgit Reger,
Dr. Christian Kölling,
Prof. Dr. Jörg Ewald
Berechtigungen: Peer Reviewed
Modelling effective thermal climate for mountain forests in the Bavarian Alps: Which is the best model? (2011) Journal of Vegetation Science 22 (4), S. 677-687.
DOI: 10.1111/j.1654-1103.2011.01270.x
Karl-Heinz Mellert,
Veronika Fensterer,
Helmut Küchenhoff,
Dr. Birgit Reger,
Prof. Dr. Jörg Ewald,
Dr. Christian Kölling,
Dr. Hans-Joachim Klemmt
Berechtigungen: Peer Reviewed
Hypothesis‐driven species distribution models for tree species in the Bavarian Alps (2011) Journal of Vegetation Science 22 (4), S. 635-646.
DOI: 10.1111/j.1654-1103.2011.01274.x
Rainer Waldhardt,
Martin Bach,
René Borresch,
Lutz Breuer,
Tim Diekötter,
Hans-Georg Frede,
Stefan Gäth,
Oliver Ginzler,
Thomas Gottschalk,
Stefan Julich,
Matthias Krumpholz,
Stefan Kuhlmann,
Annette Otte,
Dr. Birgit Reger,
Wolfgang Reiher,
Kim Schmitz,
P. Michael Schmitz,
Patrick Sheridan,
Dietmar Simmering,
Cornelia Weist,
Volkmar Wolters,
Dorit Zörner
Tim Mattern,
Annette Otte,
Rainer Waldhardt,
Dr. Birgit Reger
Berechtigungen: Peer Reviewed
Assessing the spatial distribution of grassland age in a marginal European landscape (2009) Journal of Environmental Management 90 (9), S. 2900-2909.
DOI: 10.1016/j.jenvman.2007.10.015
Grassland age is increasingly recognised to be an indicator for present-day biodiversity, e.g. plant species richness, and is also important for other landscape functions. We developed a methodological approach to systematically assess the spatial distribution of grassland age in marginal European landscapes. This approach – applied to the Lahn-Dill Highlands (1270 km2), a marginal landscape in Hesse, Germany – comprises three steps: (1) in a two-stage stratification process, we pre-stratified the study area according to recent land-cover patterns and their changes between 1955 and 1995 (stratification I) and classified grassland types by combining data on soil moisture, base-richness, and elevation (stratification II). From 50 grassland types, we randomly selected 1000 representative grassland patches. (2) We determined the age of these patches by means of aerial photograph interpretation of a chronosequence dating back to 1953 and classified each patch with respect to the age classes young (<18 years), mid-aged (18–47 years), and old (>47 years). (3) Based on this information, we calculated grassland type-specific probabilities for grassland patches to belong to the respective age classes. These probabilities were projected to districts by direct extrapolation. An exemplary validation of extrapolation results for two test areas was performed. The results revealed that 49% of the investigated patches were old grassland. The remaining patches were mid-aged (36%) or young grassland (15%). The extrapolation results indicated accordingly a predominance of old grassland at the district scale. Occurrences of mid-aged grassland were concentrated in districts with a pronounced land-cover change, whereas young grassland is apparently evenly distributed across the study area. Validation results suggest that our approach is suitable for a realistic estimation of grassland age in marginal European landscapes. The method may be applied in landscape models of various disciplines that rely on large-scale information on grassland age.
Dr. Birgit Reger,
Patrick Sheridan,
Dietmar Simmering,
Annette Otte,
Rainer Waldhardt
Since the end of World War II, marginal European landscapes with unfavourable environmental conditions for cultivation have experienced severe land-use changes. In many cases, large portions of arable land have been successively abandoned in favour of grassland or fallow land. This general trend of marginalisation in turn affected ecological landscape functions and processes with far-reaching consequences for biodiversity and natural resources. Furthermore, the land-use pattern in marginal European landscapes is expected to undergo further major changes in the future, particularly in the course of EU agricultural policy. Given this background, this multiple-paper thesis (A) analysed agricultural landscape change in a marginal agricultural landscape and (B) developed methods that may support landscape change research at multiple spatio-temporal scales. Both aims were addressed in three studies. Our study area was the Lahn-Dill Highlands (1270 km²), a marginal agricultural landscape in Hesse (Germany) with a pronounced land-use change in the past decades.In the first study, we developed an approach to identify types of land-cover patterns and dynamics (TLPDs) at the rural district scale. By the combination of recent satellite data with historic agricultural statistics, and the application of k-means cluster analysis, we identified six TLPDs and characterised their physical settings. We found a general trend of abandonment of cultivation at the landscape scale, which is governed by significant differences in current land-cover patterns and the directions of land-cover change at the district scale: In the eastern part of the area, where elevation is low, and the proportions of steep slopes and dry soils are small, land cover remained relatively stable. Slight to dramatic changes occurred, in contrast, in the remaining districts with comparatively unfavourable conditions for cultivation. In the second study, we developed a 3-step methodological approach to systematically assess the spatial distribution of grassland age in a marginal agricultural landscape. The approach is based on the combination of an a-priori two-stage landscape stratification with conventional aerial photograph interpretation of selected patches, and the subsequent spatial extrapolation of the determined grassland age. Results proved that our approach provides a realistic estimation of grassland age at the scale of districts and over a time period of five decades. We found that the derived probabilities of grassland age classes are specific for grassland types in areas with a homogenous pattern of land-cover change. Furthermore, the results indicated a predominance of old grassland patches (>47 years). Occurrences of mid-aged grassland (18-47 years) were concentrated in districts with a pronounced land-cover change in this time period, whereas young grassland (<18 years) is apparently evenly distributed across the study area. In the third study, we analysed the potential effects of three alternative transfer payment schemes on the farmland habitat diversity in a marginal agricultural landscape. We defined (1) a scenario with direct transfer payments coupled to production, (2) a scenario with direct transfer payments decoupled from production, and (3) a scenario phasing out all direct transfer payments. We characterised habitat diversity with three indices: habitat richness, evenness, and rarity. The habitat pattern in 1995 served as reference for comparison. All scenarios predicted a general trend of homogenisation of the farmland habitat pattern, yet to a differing extent. Transfer payments coupled to production (Scenario 1) supported spatially segregated land use with fallow land primarily in low-productive areas and arable land use in the more productive sites. The scenario predicted intermediate values for habitat richness and habitat evenness. Decoupling transfer payments from production (Scenario 2) favoured grassland as the most profitable farming system. This led to a grassland-dominated landscape with low values of all habitat diversity indices. Phasing out transfer payments (Scenario 3) resulted in complete abandonment or afforestation of agricultural land and extremely low values in all habitat diversity indices. Scenario results revealed that the payment of subsidies may prevent cessation of agricultural production, but may not fully counteract the homogenisation in marginal landscapes.
Mehr
Dr. Birgit Reger,
Annette Otte,
Rainer Waldhardt
Berechtigungen: Peer Reviewed
Identifying patterns of land-cover change and their physical attributes in a marginal European landscape (2007) Landscape and Urban Planning 81 (1-2), S. 104-113.
DOI: 10.1016/j.landurbplan.2006.10.018
Over the last six decades, land-cover patterns in Europe have dramatically changed, and major future changes are expected. Land-cover changes affect landscape functions. Therefore, methods are needed to include the temporal dimension into landscape classification. By combining recent satellite data with historic information on land cover from 1955, and the application of k-means cluster analysis, we developed an approach to identify types of land-cover patterns and dynamics (TLPDs) at the rural district scale. Our study area was the Lahn-Dill Highlands, a marginal German landscape with a total of 192 rural districts. We identified six TLPDs that showed a general trend of abandonment, but revealed remarkable differences in current land-cover patterns and the directions of land-cover change. The TLPDs showed notable differences in physical attributes: In the eastern part of the area, where elevation, the proportion of steep slopes, and dry soils are low, land cover remained relatively stable. Slight to dramatic changes occurred, in contrast, in the remaining districts with comparatively unfavourable conditions for cultivation. The spatially differentiated information on areas with contrasting land-cover dynamics within a region may be useful to develop effective concepts for future land management.
Betreuung der Publikationsseiten
Gerhard Radlmayr
Referent für Wissenstransfer und Forschungskommunikation
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