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

A. Ruskule et al. 2010. Patterns of afforestation process in abandoned agriculture land in Latvia
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dominated by Picea abies. Tree cover is mostly forming sparse stands. Height of Betula
pendula reaches 10. In 4th pilot area the most widespread species is Picea abies, but also Salix
spp. and Betula pendula are frequent. Maximum height of trees is 9 m. In 5th pilot area mosaic
succession pattern is dominated by Betula pendula with rather high share of Picea abies and
Pinus sylvestris. The highest trees reach 8 m. In this area tree stands are mostly dense (more
than 50 trees per 100 m 2 ). In all these pilot areas tree species cover has started to develop ca. 10
years ago. The topography of the 3rd and 4th pilot area is slightly waved, and the distribution of
soil cover is rather complex, including Luvisols, Phaeozems, Stagnosols, Gleyosols, Planosols,
as well as Arenosols and Podzols. In 5th pilot area the topography is plain and mostly covered
by Luvisols, Stagnosols, Gleysols and Arenoslos.
Continuous succession pattern has been observed at one part of the 5th pilot area – a narrow
field in earlier years used as arable land, but later regularly mowed. The tree cover has
developed just recently - during the last 2-3 years, forming rather dense stand (up to 150 trees
per 100 m 2 ) dominated by Betula pendula up to 3 m height. Development of succession from
the edge of a forest is the most explicit at the 5th pilot area where it is combined with mosaic
succession pattern. However also in 1st and 2nd pilot area influence of the forest edge or nearby
forest stand on development of linear succession pattern can be observed.
Table 1: Character of landscape ecological succession in pilot areas
Pilot area
1. pilot area village
Nurmiži
2. pilot area near
farmstead “Gobas”
3. pilot area near
village Ieriķi
4. pilot area village
Taurene
5. pilot area near
village Inciems
Pattern of
succession
Year since is
abandoned
Dominant tree species
linear 1996 Betula pendula 65%
from forest edge
Salix spp. 35%
linear 1996 Salix spp. 71%
from forest edge
Betula pendula 29%
mosaic 1995 Betula pendula 74%
Picea abies 18%
Pinus sylvestris 5,4%
mosaic 1995 Picea abies 55%
Salix spp.19%
Betula pendula 14%
continuous; 2000 Betula pendula 62%
mosaic;
Picea abies 23%
from forest edge
Pinus sylvestris 12%
Total area of the
agriculture field (ha)
425
377
135
102
38
3.2 Impact of species composition of surrounding forest on ecological succession process
Unfortunately forest taxation information was not complete (it did not include all forest stands
bordering the pilot areas) therefore comprehensive analysis of relation between species
composition in the forest stands and secondary succession patches was not possible. However
from the available information it is obvious that tree species composition not always correspond
between the succession patches and the surrounding forest. For example in 3rd pilot area
composition of the dominant species is similar (Betula pendula 50 % - in forest, 74 % - in
succession patches; Picea abies 23 % - in forest, 18 % - in succession patches), while less
dominant species present in forest (e.g. Populus tremula – 13 %; Alnus incana – 11%) can
hardly be found within the succession patches. In the 2nd pilot area where secondary
succession patches are formed by Salix spp. - 71 %, Betula pendula - 29 %, Picea abies - 0,1 %,
Alnus incana - 0,1 %, the species composition of surrounding forest stands is different (Betula
pendula -53 % and Populus tremula – 26 %, including also Picea abies - 8%, Alnus incana -
5 % and Pinus sylvestris – 3 %).
3.3 Impact of soil conditions on ecological succession process
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.