The interacting effects of land use change, climate change and suppression of natural disturbances on landscape forest structure in the Swiss Alps

Ecosystems are being modified by a multiplicity of interacting natural and anthropogenic factors. The most important of these factors include changes in land use, changes in climate, and alterations of disturbance regimes. Many studies have considered these factors separately; however, these factors do not act in isolation, but rather interact to affect ecosystem structure and function. In the present study, we analyzed the interacting effects of abandonment of agricultural practices, increases in temperature, and anthropogenic suppression of the avalanche regime on landscape forest structure (percent canopy cover) in the Davos region of the Swiss Alps over the past 45 years. Compared to 1954, the Davos region is now characterized by greater forest cover and lower landscape heterogeneity. The greatest increases in forest structural stage occurred in areas in which land use changed from agricultural to non-agricultural, that were the closest to formerly active avalanche tracks, and in which the percentage change in number of growing degree days (GDD) was high. Change in land use was the most important variable contributing to changes in landscape forest structure, followed by changes in the disturbance regime, then changes in GDD. There also exist clear interactions among these variables, which indicate, for example, that the effects of the suppression of disturbances and changes in climate are contingent on the more immediate effects of changes in land use. Understanding the relative importance of, and interactions among, changes in land use, climate, and disturbances can contribute to an improved understanding of ecosystem dynamics and to better management decisions.

[1]  L. Kullman.  Recent reversal of Neoglacial climate cooling trend in the Swedish Scandes as evidenced by mountain birch tree-limit rise , 2003 .

[2]  W. Laurance,et al.  Impacts of wind disturbance on fragmented tropical forests: A review and synthesis , 2008 .

[3]  Adrienne Grêt-Regamey,et al.  Linking GIS-based models to value ecosystem services in an Alpine region. , 2008, Journal of environmental management.

[4]  Martin Schneebeli,et al.  Temporal Trend and Spatial Distribution of Avalanche Activity during the Last 50 Years in Switzerland , 2002 .

[5]  T. D. Mitchell,et al.  An improved method of constructing a database of monthly climate observations and associated high‐resolution grids , 2005 .

[6]  Gabriele Broll,et al.  Sensitivity and response of northern hemisphere altitudinal and polar treelines to environmental change at landscape and local scales , 2005 .

[7]  Frédéric Guibal,et al.  Patterns of Land-use Abandonment Control Tree-recruitment and Forest Dynamics in Mediterranean Mountains , 2007, Ecosystems.

[8]  Patrick B. Shafroth,et al.  RIPARIAN VEGETATION RESPONSE TO ALTERED DISTURBANCE AND STRESS REGIMES , 2002 .

[9]  S. Vicente‐Serrano,et al.  Analysis of Spatial and Temporal Evolution of Vegetation Cover in the Spanish Central Pyrenees: Role of Human Management , 2004, Environmental management.

[10]  K. McGarigal,et al.  FRAGSTATS: spatial pattern analysis program for quantifying landscape structure. , 1995 .

[11]  A. Walz,et al.  Linking Models of Land Use, Resources, and Economy to Simulate the Development of Mountain Regions (ALPSCAPE) , 2007, Environmental management.

[12]  P. Shafroth,et al.  Altered stream-flow regimes and invasive plant species : the Tamarix case , 2007 .

[13]  K. Price,et al.  Regional vegetation die-off in response to global-change-type drought. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[14]  G. De’ath,et al.  CLASSIFICATION AND REGRESSION TREES: A POWERFUL YET SIMPLE TECHNIQUE FOR ECOLOGICAL DATA ANALYSIS , 2000 .

[15]  Christian Rixen,et al.  Snow avalanche disturbances in forest ecosystems—State of research and implications for management , 2009 .

[16]  A. Mather,et al.  From floods to reforestation: the forest transition in Switzerland. , 2000 .

[17]  G. Walther,et al.  Trends in the upward shift of alpine plants , 2005 .

[18]  Thomas Kitzberger,et al.  Disturbance regime and disturbance interactions in a Rocky Mountain subalpine forest , 1994 .

[19]  H. Peltola,et al.  The effects of fragmentation on the susceptibility of a boreal forest ecosystem to wind damage , 2009 .

[20]  Richard R. Kirby,et al.  Synergistic Effects of Climate and Fishing in a Marine Ecosystem , 2009, Ecosystems.

[21]  C. Körner,et al.  Tree Growth near Treeline: Abrupt or Gradual Reduction with Altitude? , 2000 .

[22]  W. Sutherland,et al.  The complexity of predicting climate-induced ecological impacts , 2007 .

[23]  R. Paine,et al.  Compounded Perturbations Yield Ecological Surprises , 1998, Ecosystems.

[24]  Matthias Bürgi,et al.  Factors and Processes Shaping Land Cover and Land Cover Changes Along the Wisconsin River , 2002, Ecosystems.

[25]  Melanie A. Harsch,et al.  Are treelines advancing? A global meta-analysis of treeline response to climate warming. , 2009, Ecology letters.

[26]  S. Carpenter,et al.  Global Consequences of Land Use , 2005, Science.

[27]  Erich Tasser,et al.  Land-use changes and natural reforestation in the Eastern Central Alps , 2007 .

[28]  Erich Tasser,et al.  Plant diversity declines with recent land use changes in European Alps , 2009, Plant Ecology.

[29]  C. Rixen,et al.  Changes in forest structure and in the relative importance of climatic stress as a result of suppression of avalanche disturbances , 2006 .

[30]  Felix Kienast,et al.  Assessing structures in mountain forests as a basis for investigating the forests' dynamics and protective function , 2001 .

[31]  C. Thomas.  Dispersal and extinction in fragmented landscapes , 2000, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[32]  Barrie Maxwell,et al.  2 – Arctic Climate: Potential for Change under Global Warming , 1992 .

[33]  C. Körner,et al.  A world‐wide study of high altitude treeline temperatures , 2004 .

[34]  Stefan Dullinger,et al.  A regional impact assessment of climate and land‐use change on alpine vegetation , 2003 .

[35]  Dominik Kulakowski,et al.  Influences of fire history and topography on the pattern of a severe wind blowdown in a Colorado subalpine forest , 2002 .

[36]  David N. Wear,et al.  Land-Use Changes in Southern Appalachian Landscapes: Spatial Analysis and Forecast Evaluation , 1998, Ecosystems.

[37]  Dominik Kulakowski,et al.  Effect of prior disturbances on the extent and severity of wildfire in Colorado subalpine forests. , 2007, Ecology.

[38]  T. Mitchell Aide,et al.  Land-Use History and Forest Regeneration in the Cayey Mountains, Puerto Rico , 2000, Ecosystems.

[39]  M. Begert,et al.  Homogeneous temperature and precipitation series of Switzerland from 1864 to 2000 , 2005 .

[40]  C. Allen,et al.  ECOLOGICAL RESTORATION OF SOUTHWESTERN PONDEROSA PINE ECOSYSTEMS: A BROAD PERSPECTIVE , 2002 .

[41]  D. Lytle,et al.  Adaptation to natural flow regimes. , 2004, Trends in ecology & evolution.

[42]  B. Koch,et al.  Agricultural land abandonment and natural forest re-growth in the Swiss mountains: A spatially explicit economic analysis , 2007 .

[43]  Peter E. Thornton,et al.  Generating surfaces of daily meteorological variables over large regions of complex terrain , 1997 .

[44]  Derek T. Robinson,et al.  Modelling carbon storage in highly fragmented and human-dominated landscapes: Linking land-cover patterns and ecosystem models , 2009 .

[45]  David R. Foster,et al.  Disturbance history, community organization and vegetation dynamics of the old-growth pisgah forest, South-Western New Hampshire, U.S.A , 1988 .

[46]  Antoine Guisan,et al.  Tree line shifts in the Swiss Alps: Climate change or land abandonment? , 2007 .

[47]  T. Kitzberger,et al.  Climatic and human influences on fire regimes in ponderosa pine forests in the Colorado Front Range. , 2000 .

[48]  F. Lloret,et al.  A comparison of the medieval and the current fire regimes in managed pine forests of Catalonia (NE Spain) , 2001 .

[49]  Natural avalanche disturbance shapes plant diversity and species composition in subalpine forest belt , 2007 .

[50]  R. Motta,et al.  Interacting effects of physical environment and anthropogenic disturbances on the structure of European larch (Larix decidua Mill.) forests , 2009 .

[51]  S. Dullinger,et al.  Modelling climate change‐driven treeline shifts: relative effects of temperature increase, dispersal and invasibility , 2004 .

[52]  P. Walther,et al.  LAND ABANDONMENT IN THE SWISS ALPS A NEW UNDERSTANDING OF A LAND-USE PROBLEM , 1986 .