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Naturreservat : en bra naturvårdsåtgärd för att bevara enskilda arter och/eller bevara den biologiska mångfalden?

<p>The examination of the adequate nature conservation methods in a natural reserve, to conserve a specific species and / or increase biological diversity is the subject of this study. This work is based on four species, that can be found during the Spring season, liverleaf, wood anemone, brimstone and woodpecker. The incidence and availability is studied and closely observed for these species in twenty forests, i.e. ten forests which are nature reserves and ten forests with the similar characteristics as the nature reserves habitat, but are not nature reserves in Gnesta mucipality, Södermanland. Measurements of the tree crown and the diameter of the tree trunks where noted to study how these factors could affect the outcome of the abundance and incidence of the four species. The brimstones lay their eggs on the leaf buds on the tree trunk. This is precisely the reason why inventories have been made for the tree trunks in the nature reserves and non protected forests. The abundance and coverage of the liverleaves and wood anemone was chosen to study in random by taking 25x25m in every forests. These squares where divided even further to ten squares with the size of 0.5x0.5m. The frequency of both the species are counted and noted in the smaller squares. The brimstones and woodpeckers are inspected by measurement assessments. Two lines of 100m were laid out, to listen to the drumming and various sounds gives of by the woodpeckers and flying adult brimstones, with a stopover of 15m in 5mins. The statistical results illustrate no significant differences in the incidence and the abundance between the liverleaves and wood anemone, whether it is in the nature reserve forests or non protected forests. But the standard deviation differed between the forests (nature reserve and non protected forests) on the incidences (nature reserve SD = 7.43, non protected forest SD = 0.31) and the abundance (nature reserve SD = 4.01, non protected forest SD = 0.51) of the liverleaves. The coverage of the tree crowns and the trunk diameter did not have any significant influence on the outcome of the abundance and the incidence of the liverleaves. The effect of the tree crown was close to non when it came to the wood anemone, but the diameter of the tree trunks affected the incidence level (DF1,7, P<0.05, F=6.4791, P<0.05, ANOVA), but not the abundance. A significantly higher value was observed among the woodpeckers in the nature reserve (b=3.584, P<0.05, logistics regression), but not among the brimstones in either the nature reserves or the forests and non protected reserves.The observation study shows that the natural reserves have greater incidences of woodpeckers and with a standard deviation of the liverleaves abundance and occurrences between nature reserve forests and non protected forests, but only with a few nature reserves having more liverleaves than other reserves. The significant difference are very marginal when it comes to liverleaves and to obtain any positive effects of the nature reserve, a large scale study needs to be conducted in far more reserve forests.</p>

Identiferoai:union.ndltd.org:UPSALLA/oai:DiVA.org:sh-3160
Date January 2009
CreatorsLundin, Ellinor
PublisherSödertörn University College, School of Life Sciences
Source SetsDiVA Archive at Upsalla University
LanguageSwedish
Detected LanguageEnglish
TypeStudent thesis, text

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