Patterns of Land-use Abandonment Control Tree-recruitment and Forest Dynamics in Mediterranean Mountains

A bstractMediterranean ecosystems have been impacted for millennia by human practices, particularly agricultural and pastoral activities. Since the middle of the nineteenth century, land-use abandonment has lead to scrubland and forest expansion, especially in mountain areas of the northern Mediterranean basin. This study aimed at analyzing how grazing history affects subsequent forest dynamics at a site located in the limestone foothills of the Southern Alps (France). The approach combines archival documents and dendroecology to investigate the origin, establishment and development of forest following land-use abandonment. Scots pine (Pinus sylvestris) started to colonize quickly in the 1870s, with the recruitment rate increasing during the first decade of the 1900s, associated with a decline of the local human population and regional livestock. Since the 1960s, European beech (Fagus sylvatica) and silver fir (Abies alba) have regenerated in the understorey of Scots pines. Regeneration is controlled by a threshold of grazing pressure. Noticeably, the rate of reforestation differs according to the former land-use, with pastures being colonized more quickly than ploughed areas. Different previous land-uses leading to different times of grazing cessation, combined with variable herbaceous competition explain the contrasting micro-scale regeneration patterns. Agricultural land-use and abandonment are both significant driving forces of vegetation dynamics. Knowledge of these factors is thus necessary to understand present patterns and to predict future forest pathways in the Mediterranean mountains.

[1]  L. Chabal,et al.  Forêts et sociétés en Languedoc (Néolithique final’ Antiquité tardive) , 1997 .

[2]  Mark Vellend,et al.  Recovery of forest plant communities in post‐agricultural landscapes , 2005 .

[3]  David R. Foster,et al.  Cultural, environmental and historical controls of vegetation patterns and the modern conservation setting on the island of Martha's Vineyard, USA , 2002 .

[4]  Jingyun Fang,et al.  Climatic limits for the present distribution of beech (Fagus L.) species in the world , 2006 .

[5]  R. Zamora,et al.  Alleviation of Summer Drought Boosts Establishment Success of Pinus sylvestris in a Mediterranean Mountain: An Experimental Approach , 2005, Plant Ecology.

[6]  S. Archer,et al.  TREES IN GRASSLANDS: BIOGEOCHEMICAL CONSEQUENCES OF WOODY PLANT EXPANSION , 2001 .

[7]  G. Peterken,et al.  Long‐term change and implications for the management of wood‐pastures: experience over 40 years from Denny Wood, New Forest , 2003 .

[8]  G. Aussenac,et al.  Ecology and ecophysiology of circum-Mediterranean firs in the context of climate change , 2002 .

[9]  Jeremy S. Pal,et al.  Consistency of recent European summer precipitation trends and extremes with future regional climate projections , 2004 .

[10]  Alain Dervieux,et al.  MEDITERRANEAN LANDSCAPE CHANGES : EVIDENCE FROM OLD POSTCARDS , 1999 .

[11]  D. Schimel,et al.  Mechanisms of shrubland expansion: land use, climate or CO2? , 1995 .

[12]  R. Zamora,et al.  Seed predation and dispersal in relict Scots pine forests in southern Spain , 1999, Plant Ecology.

[13]  H. Grip,et al.  Seedling emergence of Pinus sylvestris in characterized seedbed substrates under different moisture conditions , 2000 .

[14]  O. V. Auken.  Shrub Invasions of North American Semiarid Grasslands , 2000 .

[15]  C. Gómez-Campo.  Plant conservation in the Mediterranean area , 1986 .

[16]  P. Ciais,et al.  Europe-wide reduction in primary productivity caused by the heat and drought in 2003 , 2005, Nature.

[17]  T. Tatoni,et al.  Relative importance of abiotic and land use factors in explaining variation in woody vegetation in a French rural landscape , 1998 .

[18]  Frédéric Magnin,et al.  Secondary successions on abandoned cultivation terraces in calcareous Provence. I: Vegetations and soil , 1994 .

[19]  P. Quézel,et al.  Changes and disturbances of forest ecosystems caused by human activities in the western part of the mediterranean basin , 1990, Vegetatio.

[20]  Sandy P. Harrison,et al.  Global Biogeochemical Cycles in the Climate System , 2001 .

[21]  T. Curt,et al.  Competition for water between beech seedlings and surrounding vegetation in different light and vegetation composition conditions , 2003 .

[22]  Michela Robba,et al.  Optimizing forest biomass exploitation for energy supply at a regional level , 2004 .

[23]  Henrique M. Pereira,et al.  Ecosystem Services and Human Well-Being: a Participatory Study in a Mountain Community in Portugal , 2005 .

[24]  P. Marty,et al.  Spontaneous reforestation in a peri-Mediterranean landscape: history of agricultural systems and dynamics of woody species , 2003 .

[25]  D. Foster,et al.  Legacies of the agricultural past in the forested present: an assessment of historical land‐use effects on rich mesic forests , 2002 .

[26]  Donald L. Phillips,et al.  Rising atmospheric CO2 and carbon sequestration in forests , 2004 .

[27]  J. Blondel,et al.  Biogeography and history of the Mediterranean bird fauna , 2008 .

[28]  T. Curt,et al.  Seed mass, seed dispersal capacity, and seedling performance in a Pinus sylvestris population , 2003 .

[29]  V. Rozas.  Tree age estimates in Fagus sylvatica and Quercus robur: testing previous and improved methods , 2004, Plant Ecology.

[30]  A. Douguédroit.  Les paysages forestiers de Haute Provence et des Alpes Maritimes : géographie, écologie, histoire , 1976 .

[31]  T. Curt,et al.  Indirect facilitation and competition in tree species colonization of sub-Mediterranean grasslands , 2006 .

[32]  Ross W. Gorte,et al.  Carbon Sequestration in Forests , 2009 .

[33]  T. Curt,et al.  Growth, mortality, and morphological response of European beech and downy oak along a light gradient in sub-Mediterranean forest , 2005 .

[34]  C. Carcaillet,et al.  Large herbivores control the invasive potential of nonnative Austrian black pine in a mixed deciduous Mediterranean forest , 2006 .

[35]  S. Neuvonen,et al.  Natural regeneration of Scots pine and Norway spruce close to the timberline in northern Finland , 2006 .

[36]  F. Schweingruber.  Tree Rings: Basics and Applications of Dendrochronology , 1988 .

[37]  L. Tessier.  Spatio-temporal analysis of climate-tree ring relationships. , 1989, The New phytologist.

[38]  C. Labaune,et al.  Pastoral management vs. land abandonment in Mediterranean uplands: impact on land snail communities , 2002 .

[39]  R. Zamora,et al.  Mechanisms blocking Pinus sylvestris colonization of Mediterranean mountain meadows , 2002 .

[40]  T. Veblen,et al.  Climatic variability and episodic Pinus ponderosa establishment along the forest-grassland ecotones of Colorado , 2006 .

[41]  A. Poska,et al.  Integrated palaeoecological and historical data in the service of fine‐resolution land use and ecological change assessment during the last 1000 years in Rõuge, southern Estonia , 2005 .

[42]  D. Elston,et al.  Regeneration of Pinus sylvestris in a natural pinewood in NE Scotland following reduction in grazing by Cervus elaphus , 2000 .

[43]  S. Clark,et al.  Age estimation of Quercus marilandica and Quercus stellata: applications for interpreting stand dynamics , 2004 .

[44]  M. Applequist.  A simple pith locator for use with off-center increment cores , 1958 .

[45]  R. Zamora,et al.  Effect of browsing by ungulates on sapling growth of Scots pine in a Mediterranean environment: consequences for forest regeneration , 2001 .

[46]  E. Lingua,et al.  Human impact on size, age, and spatial structure in a mixed European larch and Swiss stone pine forest in the Western Italian Alps , 2005 .

[47]  J. Aronson,et al.  Biology and Wildlife of the Mediterranean Region , 1999 .

[48]  K. Miyanishi,et al.  The hazards of interpretation of static age structures as shown by stand reconstructions in a Pinus contorta-Picea engelmannii forest , 1994 .

[49]  R. Lawrence,et al.  Twentieth century forest-grassland ecotone shift in Montana under differing livestock grazing pressure , 2006 .

[50]  Franz Höchtl,et al.  "Wilderness": what it means when it becomes a reality - a case study from the southwestern Alps. , 2005 .

[51]  J. Vernet.  L'homme et la forêt méditerranéenne de la préhistoire à nos jours , 1997 .

[52]  Jean-Louis Martin,et al.  Rural depopulation and recent landscape changes in a Mediterranean region: Consequences to the breeding avifauna , 1997, Landscape Ecology.

[53]  S. Hagner.  Cone crop fluctuations in Scots pine and Norway spruce , 1965 .

[54]  W. Oberhuber,et al.  Topographic influences on radial growth of Scots pine (Pinus sylvestris L.) at small spatial scales , 2000, Plant Ecology.

[55]  S. Arno,et al.  Increment borer methods for determining fire history in coniferous forests , 1988 .

[56]  J. Paluch,et al.  The influence of the spatial pattern of trees on forest floor vegetation and silver fir (Abies alba Mill.) regeneration in uneven-aged forests , 2005 .

[57]  J. Piñol,et al.  Drought-induced mortality and hydraulic architecture in pine populations of the NE Iberian Peninsula , 2002 .

[58]  David R. Foster,et al.  Land-Use History as Long-Term Broad-Scale Disturbance: Regional Forest Dynamics in Central New England , 1998, Ecosystems.

[59]  T. Kajimoto,et al.  Effects of Snowfall Fluctuation on Tree Growth and Establishment of Subalpine Abies mariesii near Upper Forest-limit of Mt. Yumori, Northern Japan , 2002 .

[60]  E. Dambrine,et al.  INFLUENCE OF PAST LAND USE ON THE VEGETATION AND SOILS OF PRESENT DAY FOREST IN THE VOSGES MOUNTAINS, FRANCE , 1997 .

[61]  Charles B. Halpern,et al.  Effects of environment and grazing disturbance on tree establishment in meadows of the central Cascade Range, Oregon, USA , 1998 .

[62]  E. Despland,et al.  Climate influences on growth and reproduction of Pinus banksiana (Pinaceae) at the limit of the species distribution in eastern North America. , 1997, American journal of botany.

[63]  F. Torre,et al.  The role of landscape history and persistent biogeographical patterns in shaping the responses of Mediterranean land snail communities to recent fire disturbances , 2004 .