Landscapes Forest and Global Change - ESA - Escola Superior ...

A. Ruskule et al. 2010. Patterns of afforestation process in abandoned agriculture land in Latvia
98
afforestation, its spatial character and species composition will depend on factors like soil (its
chemical properties and humidity), terrain, initial herb layer, nearby forest, as well as former
land use (Prach et al. 2001a; Prach et al. 2001b; Barth et al 2003; Alard et al. 2005; Daugaviete
2009; Kopecký and Vojta 2009; Rosenthal (in press)). Depending on interaction of these factors
ecological succession might be either arrested or stimulated as well as leading to different
succession patterns.
Afforestation of abandoned landscape has significant effect on landscape structure and its
ecological functions (Reger et al. 2007; Stoate et al. 2009). Impacts on biodiversity might
varying – at the initial stage of afforestation habitat diversity is increasing, while in long term
perspective landscape becomes more homogenous thus reducing also biological diversity
(Fjellstad et al. 1999; Nikodemus et al. 2005; Sitzia 2010). Abandonment of agricultural land is
reducing areas important for resting, feeding or breeding of migratory birds. However secondary
succession process might be used also for restoration of natural habitats and increasing of
abundance of related animal species (Prach et al. 2001a; Stoate et al. 2009).
Land abandonment also influence the scenic quality of landscape and its identity which might
psychologically deject inhabitants causing feelings like isolation, poverty, shame etc. (Bürgi
2004; Palang et al. 2006; Benjamin 2007). Better understanding the role on environmental
factors in the process of landscape ecological succession would help to predict the course of its
development and to make optimal choice for the future use of the abandoned land.
2. Methodology
The study analyses the spatial character of landscape ecological succession and its influencing
environmental factors at the local level within selected pilot areas. The study area comprise an
abandoned agriculture land in Vidzeme, central part of Latvia, which represents typical rural
landscape including scarcely populated areas in the Gauja River valley bordering the strict
reserve zone of the Gauja National Park, as well as more densely populated areas in vicinities of
towns Sigulda, Līgatne and Taurene. The pilot areas of the study have been chosen by visual
analysis of the latest available ortophoto images from 2007. The most distinct patterns of
landscape ecological succession within the study area were selected, covering different spatial
character of shrub and tree patches and their species composition. As result 5 pilot areas have
been chosen representing 4 patterns of landscape ecological succession (see Table 1).
During the field visits actual borders of woody patches have been mapped as well as density and
composition of woody species have been assessed at the sampling sites of 10x10m, by recording
each tree and measuring their height. Sampling sites were selected within each patch, thus their
number was dependent on size of pilot area and complexity of the secondary succession pattern
(20 sampling sites in 1st pilot area; 24 - in 2nd pilot area; 26 - in 3rd pilot area; 14 - in 4th pilot
area and 15 - in 5th pilot area).
Environmental conditions and factors were described in the investigation areas. Altogether 13
soil profiles were described during field works according to the international FAO WRB
classificator (IUSS Working Group WRB, 2007), 57 soil samples were collected from soil
profile diagnostic horizons and physical and chemical analyses were done in the laboratory
according to the methodology of ICP Forest monitoring (Manual on methods…, 2006). Impacts
of nearby forest stand and its species composition on the character of ecological succession have
been defined by analysing the forest taxation maps obtained from the State Forest Service.
Impacts of drainage systems have been analysed using the melioration maps of the former
collective farms. Information on former land use and period since agriculture practice has been
given up were obtained from local inhabitants and landowners by direct interviews at the pilot
Forest Landscapes and Global Change -New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.