Hotbild för ädellav Megalaria grossa i Uppland och på Gotland
Megalaria grossa is classified as Near treatened on the Swedish Red List. It is also a so called signals spieces, e. g. a spieces that function as an indicator, signalling a forest that is worthy of protection. The aim of this study was to clarify the status at selected localities in the province of...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Ecology
2008
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| Materias: |
| _version_ | 1855571997827792896 |
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| author | Ring, Karolin |
| author_browse | Ring, Karolin |
| author_facet | Ring, Karolin |
| author_sort | Ring, Karolin |
| collection | Epsilon Archive for Student Projects |
| description | Megalaria grossa is classified as Near treatened on the Swedish Red List. It is also a so called signals spieces, e. g. a spieces that function as an indicator, signalling a forest that is worthy of protection. The aim of this study was to clarify the status at selected localities in the province of Uppland and Gotland. 12 old localities, were visited in Uppland and 3 wooded meadow on Gotland. A wooded meadow is an open meadow with some segments of trees and bushes; it has a long term management with, for example, spring clearing, hay-making and grazing.
The results showed that M. grossa had decreased in 2 out of the 3 wooded meadows compared to an inventory at 1989. In Tjängdarve, M. grossa decreased from 7 to 1 inventoried trees along a transect and in Lojsta from 8 to 1 trees between the years 1989 to 2007. In the wooded meadow of Laxare there were no changes. The average circumference of the trees in Lojsta and Laxare has increased with 30 % whereas the distance between the trees remains unchanged since 1989. In Laxare the average circumference of the trees has increase with 17 % and the distance between the trees has decreased. The decrease of the M. grossa population in the wooded meadows might depend on the fact that the wooded meadows have become denser and therefore darker. Another reason may be impact from e.g. air pollution.
In the province of Uppland M. grossa was found in 7 out of 12 known localities. The forest in this area has become denser and the future for M. grossa at the localities is obscure. Moreover, Picea abies has increased rapidly at the localities. The old deciduous trees at the localities should be protected and forest clearance is one measure that could be carried out to ensure the continuous growth of M. grossa. If nothing is done the population of M. grossa is likely to continue decrease in Sweden which may lead to a change of categorization in the Swedish Red List from Near Threatened to Vulnerable. Finally, due to more dense forests, also other species occurring in the same habitat will certainly decrease as well. |
| format | L3 |
| id | RepoSLU12089 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2008 |
| publishDateSort | 2008 |
| publisher | SLU/Dept. of Ecology |
| publisherStr | SLU/Dept. of Ecology |
| record_format | eprints |
| spelling | RepoSLU120892017-11-08T08:13:41Z Hotbild för ädellav Megalaria grossa i Uppland och på Gotland Ring, Karolin Megalaria grossa ädellav änge ädellövträd grova lövträd asp ask löväng Megalaria grossa is classified as Near treatened on the Swedish Red List. It is also a so called signals spieces, e. g. a spieces that function as an indicator, signalling a forest that is worthy of protection. The aim of this study was to clarify the status at selected localities in the province of Uppland and Gotland. 12 old localities, were visited in Uppland and 3 wooded meadow on Gotland. A wooded meadow is an open meadow with some segments of trees and bushes; it has a long term management with, for example, spring clearing, hay-making and grazing. The results showed that M. grossa had decreased in 2 out of the 3 wooded meadows compared to an inventory at 1989. In Tjängdarve, M. grossa decreased from 7 to 1 inventoried trees along a transect and in Lojsta from 8 to 1 trees between the years 1989 to 2007. In the wooded meadow of Laxare there were no changes. The average circumference of the trees in Lojsta and Laxare has increased with 30 % whereas the distance between the trees remains unchanged since 1989. In Laxare the average circumference of the trees has increase with 17 % and the distance between the trees has decreased. The decrease of the M. grossa population in the wooded meadows might depend on the fact that the wooded meadows have become denser and therefore darker. Another reason may be impact from e.g. air pollution. In the province of Uppland M. grossa was found in 7 out of 12 known localities. The forest in this area has become denser and the future for M. grossa at the localities is obscure. Moreover, Picea abies has increased rapidly at the localities. The old deciduous trees at the localities should be protected and forest clearance is one measure that could be carried out to ensure the continuous growth of M. grossa. If nothing is done the population of M. grossa is likely to continue decrease in Sweden which may lead to a change of categorization in the Swedish Red List from Near Threatened to Vulnerable. Finally, due to more dense forests, also other species occurring in the same habitat will certainly decrease as well. För att studera aktuell status och hotbild för ädellav Megalaria grossa har 12 lokaler i Uppland och tre ängen på Gotland inventerats. Ett änge är en äng med inslag av lövträd och buskar och sköts traditionellt med slåtter, fagning och hamling. M. grossa är en art som är kategoriserad som Missgynnad (NT) i den svenska rödlistan. M. grossa är också en signalart som påvisar skyddsvärd skog. I 2 av 3 av de gotländska ängena som inventerades har M. grossa minskat jämfört med en inventering från 1989, Lojsta prästänge och Tjängdarve änge. I Lojsta har M. grossa minskat från 7 till 1 i träd vid en linjeinvetering och från 8 till 1 träd i Tjängdarve medan den i Laxare änge har en oförändrad population. I Lojsta- och Tjängdarve änge har medelomkretsen av träden ökat med ca 30 % samtidigt som avståndet mellan träden är lika stort som 1989. Minskningen av M. grossa kan bero på att skuggningen av enskilda trädstammar ökat eller storskaliga fenomen som luftföroreningar. I Uppland återfanns M. grossa på 7 av 12 tidigare kända fyndlokaler. Lokalerna är för täta för att M. grossa ska finnas kvar på långt sikt och andelen gran har ökat. För att gynna M. grossa bör grova lövträd i lokalerna skyddas mot kraftig igenväxning liksom slutavverkning. Även röjning av framförallt gran på lokalerna och/eller bete vore en åtgärd som skulle gynna M. grossa. Om inga åtgärder genomförs kommer M. grossa sannolikt att fortsätta minska i framtiden vilket kan komma att leda till att den måste flytta från Missgynnad (NT) till Sårbar (VU) på rödlistan. Eftersom lokalerna är på god väg att växa igen påverkas inte bara M. grossa utan även andra arter som man kan finna i samma miljö. SLU/Dept. of Ecology 2008 L3 swe eng https://stud.epsilon.slu.se/12089/ |
| spellingShingle | Megalaria grossa ädellav änge ädellövträd grova lövträd asp ask löväng Ring, Karolin Hotbild för ädellav Megalaria grossa i Uppland och på Gotland |
| title | Hotbild för ädellav Megalaria grossa i Uppland och på Gotland |
| title_full | Hotbild för ädellav Megalaria grossa i Uppland och på Gotland |
| title_fullStr | Hotbild för ädellav Megalaria grossa i Uppland och på Gotland |
| title_full_unstemmed | Hotbild för ädellav Megalaria grossa i Uppland och på Gotland |
| title_short | Hotbild för ädellav Megalaria grossa i Uppland och på Gotland |
| title_sort | hotbild för ädellav megalaria grossa i uppland och på gotland |
| topic | Megalaria grossa ädellav änge ädellövträd grova lövträd asp ask löväng |