Changes of pastures in riparian lands through last eight decades in Latvia

Transcription

1 Changes of pastures in riparian lands through last eight decades in Latvia Marcis Saklaurs Liga Liepa, Inga Straupe, Janis Krumins, Ilze Jekabsone Latvia University of Agriculture Evora, Portugal, 216

2 ry facts about Latvia Export from the forestry 2 bilion euro Half of Latvia is covered by forest Employed people The growing stock million m3 Annual increment 25 million m3 Cutting volume 12 million m3

3 Introduction During the 2th century large scale agricultural practice was in Latvia Small scale farming was done all over Latvia including riparian lands with low agricultural value, uneven terrain and specific hydrological regime Since the renewal of independent Republic of Latvia, agricultural activities within the riparian territories, for several reasons (economic situation, urbanization and general migration) has been in serious decline land grows from 23% (1923) to 56 % (216)

4 Introduction_riparian lands - Significant role in the functioning of ecosystems and biodiversity conservation - Riparian forests are the transition zone between water and terrestrial ecosystems - Dense river network in Latvia with the average density of.6 km * km -2 - Past grasslands, including protected European Union habitats grasslands (codes 612*, 621, 627*, 643, 651) are overgrown with pioneer species of trees grey alder Alnus incana, European aspen Populus tremula and the common birch Betula pendula - Territories have been transformed from riparian grasslands into riparian forests

5 Methods_1 - The study area (Fig 1) is situated in southern, western and northern parts of Latvia Zemgale, Kurzeme, Vidzeme - In total, 9 study sites were established and assessed - In total, 15 streams (Fig 2) were selected for analysis according to management plans of Lielupe, Venta and Gauja river basins Fig. 1. Locations ofstudy sites in Latvia Fig 2. Study area: river Svētupe (North Latvia)

6 Methods_2 - The area of each sample plot is 2 2m (4 m 2 ) - Sample plots were established at the distance of 1 3m and 6 8m from the stream banks (Fig 3) - The Braun-Blanquet method was used to describe the plant communities: the total projective coverage of moss (E), herb (E1), shrub (E2) and tree (E3) layer - Analyze aerophoto and land use from present to Fig 3. Method of field work for riparian forest assesment

7 Species richness (N) Results_1 Shannon diversity 3 2 Shannon diversity index for species in all vegetation layers Species richness per vegetation layers Moss layer Herb layer Shrub layer Tree layer

8 Coverage (%) Results_2 8 Shannon diversity index, herb layer, non-significant Moss layer Herb layer Shrub layer Tree layer Projective coverage per vegetation layers, non-significant

9 Proportion of coverage (%) Proportion of species richness (N) 5 Results_ Boreal F vs non-f p<.5 pine forests F vs non-f p<.5 1 advent boreal meadow nemoral nitrophilous pine forest water-swamp Boreal F vs non-f p<.5 nitrophilous F vs non-f p<.5 pine forests F vs non-f p<.5 1 advent boreal meadow nemoral nitrophilous pine forest water-swamp

10 Proportion of coverage (%) Proportion of species richness (N) 5 Results_4 4 cr strategy F vs non-f p<, c cr cs csr r s cr F vs non-f p<,5 r F vs non-f p<,5 1 c cr cs csr r s

11 Proportion of coverage (%) Proportion of species richness (N) 5 Results_5 4 3 Chamaephyte F vs non-f p< Chamaephyte F vs non-f p<,5 Therophyte F vs non-f p<,5 1

12 Volume, m 3 /ha Volume, m 3 /ha Results_ Snags and stems Logs

13 Conclusions In conclusion, vegetation composition in riparian forests is affected by forest stand age and it plays an important role for appropriate functioning of riparian buffer strips. Analyzes of plant composition shows a significant difference by the strategy types, life forms, functional groups Large variations of species in non-f stands, still active succession

14 Thank you!