Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt
Reindeer husbandry and Forestry are both area related industries and will in big extent use the same lands. Conflicts often arise because of that the industries have different interests. Many of the activities done by the forestry influences the reindeer husbandry in an undesirable way, simultaneous...
| Autor principal: | |
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| Formato: | L3 |
| Lenguaje: | sueco Inglés |
| Publicado: |
SLU/Dept. of Forest Ecology and Management
2007
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| Materias: |
| _version_ | 1855571988198719488 |
|---|---|
| author | Werndin, Lisa |
| author_browse | Werndin, Lisa |
| author_facet | Werndin, Lisa |
| author_sort | Werndin, Lisa |
| collection | Epsilon Archive for Student Projects |
| description | Reindeer husbandry and Forestry are both area related industries and will in big extent use the same lands. Conflicts often arise because of that the industries have different interests. Many of the activities done by the forestry influences the reindeer husbandry in an undesirable way, simultaneously as the reindeer husbandry activities can have negative consequences for the forestry. One such forestry activity is fertilization.
It was during the 1960´s forest fertilization began to be practiced and the reason was that the increase in growth that the fertilization gave could be able to cover for the future shortage in wood many feared.
During the 1970´s when the fertilizing activities were most intensive about 200 000 ha was fertilized annually. The uncertainty about which consequences N-fertilization would have on the ecosystems gave a decrease in fertilizing activities, and in the beginning of the 21th century only 30 000 ha was fertilized every year. Much research has been concentrated to questions concerning fertilizing and the knowledge about the production effects and the consequences on the environment has improved. This in combination with the great demand of wood and high woodprices has again made it interesting to fertilize the forest, to make it possible to take out larger volumes from the forests. The aim of this study was to evaluate the consequences intensive forest fertilization in older pine stands have on species in field- and bottom layer, mainly the species that is of importance for the reindeer and the reindeer husbandry.
The study was carried out in an area 10 km SE of Åsele where SCA Forest Products since 1982 is pursuing an experiment concerning intensive forest fertilizing in older pine stands (Pinus sylvestris). The intention with the original experiment was to study how different fertilizing intervals influence growth plus to investigate whether an intensive fertilizing program can evoke shortage in boron and/or other micronutrients. When the experiment was constructed the stand contained 75 years old pines with a site index of T18 (H100), 990 stems/ha, a basal area of 14 m2/ha and a volume of 105 m3/ha.
The experimental plots that had been fertilized every second year (treatment 2-4) differed most regarded to the tree layers characteristics. The basal areas were among the highest for both living and dead trees. Occurrence of a lower tree layer was only visible in these experimental plots and also the crown density was the highest in the experimental plots that had been fertilized most intensive (2-4). In total, seven species were observed in the field layer: lingonberry, blueberry, heather, crowberry, common hair-grass (Deschampsia flexuosa), fire weed (Epilobium augustifolium) and raspberry. For none of the seven species it was possible to find any statistic significant differences between the different treatments. When fertilized plots was compared with unfertilized the occurrence of lingonberry was significantly lower in the fertilized experimental areas (3,3 % compared to 5,8 %). Feather mosses, litter, reindeer lichens, Dicranum scoparium and hair-mosses made up the bottomlayer. In the bottom layer the difference in occurrence of reindeer lichens and litter between the experimental areas was statistically significant. When fertilized plots were compared with unfertilized significant differences was found for feather mosses, litter and reindeer lichens. The fertilized plots had lower cover of feather mosses (61,9 % compared to 92,7 %) and reindeer lichens (0,55 % compared to 3,3 %) but higher cover of litter (34,8 % compared to 2,5 %). The cover of reindeer lichens was thus in general low, even in the control, which probably depend on the fact that the stand had a high canopy closure with large litterfall and low level of light to the ground.
Intensive fertilization in older pine stands seems thus to bring negative consequences for the reindeer and the reindeer husbandry. The one from the nourishment point of view so important reindeer lichens were decreased and the lingonberry, who can act as a protective shelter, and with that prevent the formation of an ice layer close to the ground, was also decreased. This means that there is a high probability that the reindeer lichens that may remain will be inaccessible under an icelayer. It should also be noticed that a normal succession bring about a reduction in the cover of the reindeer lichens when a tree stand is growing older and the canopy is closing. In the current stand commercial thinning might be the most important measure to improve the light conditions, reduce the quantity of needle litter and improve the reindeer lichens growth conditions. |
| format | L3 |
| id | RepoSLU12037 |
| institution | Swedish University of Agricultural Sciences |
| language | swe Inglés |
| publishDate | 2007 |
| publishDateSort | 2007 |
| publisher | SLU/Dept. of Forest Ecology and Management |
| publisherStr | SLU/Dept. of Forest Ecology and Management |
| record_format | eprints |
| spelling | RepoSLU120372017-11-13T11:47:22Z Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt Effects of fertilization in mature Pine stands on species grazed by reindeer in field- and bottom layer Werndin, Lisa kvävegödsling fältexperiment inventering renlavar rennäring Reindeer husbandry and Forestry are both area related industries and will in big extent use the same lands. Conflicts often arise because of that the industries have different interests. Many of the activities done by the forestry influences the reindeer husbandry in an undesirable way, simultaneously as the reindeer husbandry activities can have negative consequences for the forestry. One such forestry activity is fertilization. It was during the 1960´s forest fertilization began to be practiced and the reason was that the increase in growth that the fertilization gave could be able to cover for the future shortage in wood many feared. During the 1970´s when the fertilizing activities were most intensive about 200 000 ha was fertilized annually. The uncertainty about which consequences N-fertilization would have on the ecosystems gave a decrease in fertilizing activities, and in the beginning of the 21th century only 30 000 ha was fertilized every year. Much research has been concentrated to questions concerning fertilizing and the knowledge about the production effects and the consequences on the environment has improved. This in combination with the great demand of wood and high woodprices has again made it interesting to fertilize the forest, to make it possible to take out larger volumes from the forests. The aim of this study was to evaluate the consequences intensive forest fertilization in older pine stands have on species in field- and bottom layer, mainly the species that is of importance for the reindeer and the reindeer husbandry. The study was carried out in an area 10 km SE of Åsele where SCA Forest Products since 1982 is pursuing an experiment concerning intensive forest fertilizing in older pine stands (Pinus sylvestris). The intention with the original experiment was to study how different fertilizing intervals influence growth plus to investigate whether an intensive fertilizing program can evoke shortage in boron and/or other micronutrients. When the experiment was constructed the stand contained 75 years old pines with a site index of T18 (H100), 990 stems/ha, a basal area of 14 m2/ha and a volume of 105 m3/ha. The experimental plots that had been fertilized every second year (treatment 2-4) differed most regarded to the tree layers characteristics. The basal areas were among the highest for both living and dead trees. Occurrence of a lower tree layer was only visible in these experimental plots and also the crown density was the highest in the experimental plots that had been fertilized most intensive (2-4). In total, seven species were observed in the field layer: lingonberry, blueberry, heather, crowberry, common hair-grass (Deschampsia flexuosa), fire weed (Epilobium augustifolium) and raspberry. For none of the seven species it was possible to find any statistic significant differences between the different treatments. When fertilized plots was compared with unfertilized the occurrence of lingonberry was significantly lower in the fertilized experimental areas (3,3 % compared to 5,8 %). Feather mosses, litter, reindeer lichens, Dicranum scoparium and hair-mosses made up the bottomlayer. In the bottom layer the difference in occurrence of reindeer lichens and litter between the experimental areas was statistically significant. When fertilized plots were compared with unfertilized significant differences was found for feather mosses, litter and reindeer lichens. The fertilized plots had lower cover of feather mosses (61,9 % compared to 92,7 %) and reindeer lichens (0,55 % compared to 3,3 %) but higher cover of litter (34,8 % compared to 2,5 %). The cover of reindeer lichens was thus in general low, even in the control, which probably depend on the fact that the stand had a high canopy closure with large litterfall and low level of light to the ground. Intensive fertilization in older pine stands seems thus to bring negative consequences for the reindeer and the reindeer husbandry. The one from the nourishment point of view so important reindeer lichens were decreased and the lingonberry, who can act as a protective shelter, and with that prevent the formation of an ice layer close to the ground, was also decreased. This means that there is a high probability that the reindeer lichens that may remain will be inaccessible under an icelayer. It should also be noticed that a normal succession bring about a reduction in the cover of the reindeer lichens when a tree stand is growing older and the canopy is closing. In the current stand commercial thinning might be the most important measure to improve the light conditions, reduce the quantity of needle litter and improve the reindeer lichens growth conditions. Rennäringen och skogsbruket är båda areella näringar och skall i stor utsträckning nyttja samma marker. Konflikter uppstår ofta på grund av att näringarna har olika intressen. Många av skogsbrukets aktiviteter påverkar rennäringen på ett icke önskvärt sätt samtidigt som rennäringens verksamhet kan få negativa konsekvenser för skogsbruket. En sådan skogsbruksaktivitet är gödsling. Det var under 1960-talet som skogsgödsling började praktiseras och anledningen var att den tillväxtökning som gödslingen gav skulle kunna täcka upp den framtida virkesbrist som befarades. På 1970-talet när gödslingsverksamheten var som mest intensiv gödslades årligen ca 200 000 ha. Osäkerheten kring vilka konsekvenser N-gödsling skulle ha på ekosystemen gjorde dock att gödslingsaktiviteten gick ner och omfattade i början på 2000-talet bara 30 000 ha varje år. Mycket forskning har koncentrerats till frågor rörande gödsling och kunskaperna kring produktionseffekter och miljökonsekvenser har förbättrats. Detta i kombination med den stora efterfrågan på virke och de höga virkespriserna har gjort att det åter blivit intressant att gödsla skogen, för att kunna plocka ut ännu större volymer ur skogen. Syftet med det här arbetet har varit att ta reda på vilka konsekvenser intensiv skogsgödsling i äldre tallbestånd har på arter i fält- och bottenskikt, främst de arter som är av betydelse för renen och rennäringen. Studien genomfördes i ett område som låg 10 km sydost om Åsele där SCA Forest Products sedan 1982 bedriver ett intensivgödslingsförsök i äldre tallskog (Pinus sylvestris). Avsikten med det ursprungliga försöket var att studera hur olika gödslingsintervall påverkar tillväxten samt att utreda huruvida ett intensivt gödslingsprogram kan framkalla brist på bor och/eller andra mikronäringsämnen. Vid anläggning av försöket bestod beståndet av 75-åriga tallar med ståndortsindex T18 (H100), 990 stammar/ha, en grundyta på 14 m2/ha och en volym på 105 m3sk/ha stamantal. Försöksleden som gödslats vart annat år (försöksled 2-4) var de mest avvikande vad gäller trädskiktets egenskaper. De uppmätta grundytorna tillhörde de högsta värdena både vad gäller levande och döda träd. Förekomst av ett undre trädskikt kunde bara noteras i dessa försöksled och krontäckningen var också störst i de mest intensivt gödslade försöksleden (2-4). Totalt observerades och noterades sju arter i fältskiktet, lingon, blåbär, ljung, kråkbär, kruståtel, mjölkört och hallon. Inte för någon av de sju observerade arterna i fältskiktet gick det att finna några statistiskt signifikanta skillnader mellan de olika försöksleden. Vid jämförelsen gödslat mot ogödslat var förekomsten av lingon signifikant lägre i de gödslade försöksleden (3,3 % respektive 5,8 %). Väggmossa, förna, renlavar, kvastmossa och björnmossa utgjorde bottenskiktet. I bottenskiktet var skillnaderna i förekomst av renlav och förna mellan de olika försöksleden statistiskt signifikanta. När analysen gödslat mot ogödslat genomfördes kunde statistiskt signifikanta skillnader påvisas för väggmossa, förna och renlavar. De gödslade försöksleden hade lägre täckningsgrad av väggmossa (61,9 % resp. 92,7 %) och renlavar (0,55 % resp. 3,3%) men högre täckningsgrad av förna (34,8 % resp. 2,5 %). Täckningsgraden för renlav var alltså generellt låg, även i kontrollen, vilket förmodligen beror på att beståndet var väl slutet med stort förnafall och låg ljusnivå på marken. Intensiv gödsling av äldre tallbestånd verkar alltså medföra negativa konsekvenser för renen och rennäringen. Den för renen ur näringssynpunkt så viktiga laven missgynnas och lingonriset, som kan fungera som en skyddande skärm och därmed förhindra isbildning närmast marken, minskar också. Det betyder att det är stor risk att de lavar som eventuellt finns kvar blir oåtkomliga under ett isskikt. Det bör dock också noteras att en normal succession medför att renlavars täckningsgrad minskar när ett trädbestånd blir gammalt och sluter sig. I det aktuella beståndet kanske gallring är den viktigaste åtgärden för att öka ljustillgången, reducera mängden barrförna och förbättra renlavens växtmiljö. SLU/Dept. of Forest Ecology and Management 2007 L3 swe eng https://stud.epsilon.slu.se/12037/ |
| spellingShingle | kvävegödsling fältexperiment inventering renlavar rennäring Werndin, Lisa Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| title | Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| title_full | Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| title_fullStr | Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| title_full_unstemmed | Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| title_short | Effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| title_sort | effekter av gödsling i äldre tallbestånd på renbetesväxter i fält- och bottenskikt |
| topic | kvävegödsling fältexperiment inventering renlavar rennäring |