| 1. |
- Caruso, Alexandro, et al.
(författare)
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Colonization-extinction dynamics of epixylic lichens along a decay gradient in a dynamic landscape
- 2010
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 119, s. 1947-1953
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Tidskriftsartikel (refereegranskat)abstract
- Metapopulation models are often used for understanding and predicting species dynamics in fragmented landscapes. Several models have been proposed depending on e.g. the relative importance of patch dynamics on the metapopulation dynamics. Dead wood is a dynamic substrate patch, and species that are confined to such patches have experienced a high degree of habitat loss in managed forests. Little is, however, known about how the population dynamics of epixylic species are affected by the fast dynamics of their substrate patches. We quantified the effect of local patch conditions and metapopulation processes on colonizations and extinctions of epixylic lichen species in a managed boreal forest landscape. This was done by twice surveying seven lichen metapopulations on 293 stumps in 30 stands of ages covering the duration of the dynamic patches (stumps). We also investigated the relative importance of local stochastic extinctions from stumps that remained available, and deterministic extinctions due to stump surface disappearance. We found importance of a decay gradient, surrounding metapopulation size, and local population sizes, in driving the colonization-extinction dynamics of epixylic lichens. The species were sorted along the stump decay gradient. Increasing surrounding metapopulation size was associated with increased colonization rates, and increasing local population size decreased lichen extinction rates. Finally, both local stochastic extinctions and deterministic extinctions due to patch disappearance occur, confirming that the long-term persistence of epixylic lichens depends on colonization rates that compensate for stochastic population extinctions as well as deterministic extinctions.
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| 2. |
- Caruso, Alexandro, et al.
(författare)
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Different patterns in species richness and community composition between trees, plants and epiphytic lichens in semi-natural pastures under agri-environment schemes
- 2015
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Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 24, s. 1729-1742
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Tidskriftsartikel (refereegranskat)abstract
- Agri-environment schemes (AES) have been established to counteract negative effects of agricultural intensification on e.g. semi-natural pastures and meadows. The efficiency of most AESs have, however, been poorly evaluated. We evaluated the success of a Swedish AES for the management of semi-natural pastures by comparing species richness and composition of vascular plants (except trees), epiphytic lichens and trees among pastures receiving higher (high value pastures) and lower levels of AES paymens (general value pastures). There was no difference in the number of tree species among high and general value pastures, even though AES regulations allow a maximum of 60 and 100 trees/ha in general and high value pastures, respectively. High value pastures had, however, a higher number of plant and epiphytic lichen species than common value pastures. Moreover, a higher number of pasture specialist plant species were indicative of high value pastures than of general value pastures. No lichen species indicating high value pastures are associated with habitats with low canopy cover (such as e.g. pastures). Finally, tree identity was an important factor for explaining the number and composition of epiphytic lichen species. Our study highlights that species groups can respond differently to agri-environment schemes and other conservation measures. Even though the effects are the desired on the diversity of one assessed taxon, this is not always the case for non-target organism groups.
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| 3. |
- Caruso, Alexandro, et al.
(författare)
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Influence of substrate age and quality on species diversity of lichens and bryophytes on stumps
- 2009
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Ingår i: Bryologist. - : American Bryological and Lichenological Society. - 0007-2745. ; 112, s. 520-531
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Tidskriftsartikel (refereegranskat)abstract
- Stumps from the last felling constitute a large proportion of dead wood in young managed forests. Yet, the knowledge of the diversity of stump-inhabiting organisms is poor. We studied the importance of substrate age and quality to lichen and bryophyte diversity on the cut surface of stumps in south-central Sweden. In total, we found 53 lichens and 35 bryophytes on 449 Norway spruce stumps in a forest stand chronosequence of four age classes: 4-5, 8-9, 12-13 and 16-18 years old stands. The influence of substrate age and substrate quality on species diversity differed between lichens and bryophytes. Lichen species richness was higher for age classes 2-4 compared to age class 1, whereas bryophyte richness was higher in age classes 3-4 than in 1. Further, lichen richness increased with increasing stump height and the presence of surface structural components (chairs and levels), which together with decay also influenced lichen species composition. Conversely, increasing stump height and the presence of levels decreased bryophyte richness, which in turn increased with increasing decay, surface area and number of surrounding trees and shrubs. Only decay explained differences in bryophyte species composition. Stumps in this region seem more important to overall lichen diversity, because there were on average more lichen species per stump and we only found common bryophytes but several uncommon lichens. The different responses of lichens and bryophytes to age and substrate variables indicates, however, the importance of including several organism groups in species diversity studies of dead wood.
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| 4. |
- Caruso, Alexandro, et al.
(författare)
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Positive edge effects on forest-interior cryptogams in clear-cuts
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:11, s. e27936-
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Tidskriftsartikel (refereegranskat)abstract
- Biological edge effects are often assessed in high quality focal habitats that are negatively influenced by human-modified low quality matrix habitats. A deeper understanding of the possibilities for positive edge effects in matrix habitats bordering focal habitats (e.g. spillover effects) is, however, essential for enhancing landscape-level resilience to human alterations. We surveyed epixylic (dead wood inhabiting) forest-interior cryptogams (lichens, bryophytes, and fungi) associated with mature old-growth forests in 30 young managed Swedish boreal forest stands bordering a mature forest of high conservation value. In each young stand we registered species occurrences on coarse dead wood in transects 0–50 m from the border between stand types. We quantified the effect of distance from the mature forest on the occurrence of forest-interior species in the young stands, while accounting for local environment and propagule sources. For comparison we also surveyed epixylic open-habitat (associated with open forests) and generalist cryptogams. Species composition of epixylic cryptogams in young stands differed with distance from the mature forest: the frequency of occurrence of forest-interior species decreased with increasing distance whereas it increased for open-habitat species. Generalists were unaffected by distance. Epixylic, boreal forest-interior cryptogams do occur in matrix habitats such as clear-cuts. In addition, they are associated with the matrix edge because of a favourable microclimate closer to the mature forest on southern matrix edges. Retention and creation of dead wood in clear-cuts along the edges to focal habitats is a feasible way to enhance the long-term persistence of epixylic habitat specialists in fragmented landscapes. The proposed management measures should be performed in the whole stand as it matures, since microclimatic edge effects diminish as the matrix habitat matures. We argue that management that aims to increase habitat quality in matrix habitats bordering focal habitats should increase the probability of long-term persistence of habitat specialists.
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| 5. |
- Eriksson, Olof, 1934-, et al.
(författare)
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Use and abuse of reindeer range
- 2007
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- In consequence of variations in geology and soils, in climate, and in its wide extent in longitude, latitude and altitude, the Scandinavian mountain chain exhibits major variations in natural conditions. Nature is constantly influenced by processes that include both natural forces and human activity.In the early 1990s, there was an intense media debate about current damage to the montane vegetation, which many believed they could observe.In 1992, the World Wide Foundation for Nature, WWF, invited representatives of responsible authorities, reindeer-husbandry interests, voluntary conservation bodies and interested researchers to a conference, which, somewhat erroneously, came to be called the 'Reindeer grazing conference', but which included a spectrum of factors that can affect the montane vegetation.One result of this conference was that, in 1993, WWF initiated a research project, extending over several years, intended to provide information about temporal changes in montane vegetation.Experimental areas distributed along the Swedish mountain chain were selected: the southernmost are on Fulufjället in Dalama, and the northernmost are ea. 15 km S of Tavvavuoma in Swedish Lapland. (Some placenames are given in modern North-Saamish spelling in Appendix 2) The vegetation types studied were Grass heath, Meadow with low herbs, Dry heath, Birch forest-heath type with lichens and Birch forest-heath with mosses. These cover all major montane areas and are important grazing areas for reindeer.At all study sites, six adjacent plots were selected, half of which were fenced to deny access to larger herbivores, and half were left open for grazing by all herbivores. The composition of plant communities in the field, bottom and tree layer in plots was estimated in 1995-96, and re-estimated three to four years later.Generally, marginal or no effects of enclosure were seen on the vegetation communities, and there were no differences between vegetation types.Up to the end of the 19th century, travellers in the montane region, both Saami and outsiders, ocularly assessed the plant cover. As a rule, they reported a good supply of reindeer fodder plants, especially lichen species.From the end of the 19th century, there began to be observations of severely denuded lichen cover, especially in areas exposed to a veritable invasion of Saami and reindeer from the north-Norwegian and north-Finnish reindeer grazing areas. Incomers from those areas introduced an extensive form of reindeer husbandry, developed to suit conditions on the Finnmarksvidda and in northernmost Finland, where large reindeer herds could readily find grazing on well-demarcated headlands and islands during the snowfree season, without much supervision.The conflicts of interest between the incomers, and indigenous Saami who wished to carry on an intensive form of reindeer husbandry, with closely supervised herds, were great. From the beginning of the 20th century, state interventions, in the form of commissions of enquiry and field surveys, were instituted. Their aim was to resolve existing conflicts, to ensure a sustainable access to grazing, and satisfactory profitability. The results cannot be said to have been satisfactory.
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| 6. |
- Frisch, Andreas, et al.
(författare)
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Tree Species Composition Predicts Epiphytic Lichen Communities in an African Montane Rain Forest
- 2015
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Ingår i: Biotropica. - : Wiley. - 0006-3606. ; 47, s. 542-549
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Tidskriftsartikel (refereegranskat)abstract
- The ecology of many tropical rain forest organisms, not the least in Africa, remains poorly understood. Here, we present a detailed ecological study of epiphytic lichens in the equatorial montane rain forest of Bwindi National Park (331km(2)), Uganda. We evaluated all major lichen growth forms, including selected groups of crustose lichens. In 14 transects at elevations of 1290m to 2500m, we sampled 276 trees belonging to 60 species. We recorded all lichen species on each tree trunk between ground level and 2m above the ground, yielding 191 lichen species in 67 genera, with a mean of 4.7 species per tree. We used non-metric multi-dimensional scaling to separate epiphytic lichen assemblages according to tree species composition and elevation. Structural equation modeling indicated that elevation influenced tree species composition and that tree species composition largely determined lichen species composition. Thus, elevation acted indirectly on the lichen assemblages. Further studies examining factors such as bark properties and lichen colonization ecology may clarify what determines the association between tree species and lichen assemblages. The link between lichen assemblages and large-scale elevation patterns, as well as disturbance and regrowth histories, warrants further study. An analysis of lichen species composition on individual tree species that occur over large elevation ranges would distinguish the effect of tree species on lichen assemblages from the effect of elevation and thus climate. Our study highlights the limited extent of our knowledge of tropical epiphytic lichens.
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| 7. |
- Gustafsson, Lena, et al.
(författare)
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Natural Versus National Boundaries: The Importance of Considering Biogeographical Patterns in Forest Conservation Policy
- 2015
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Ingår i: Conservation Letters. - : Wiley. - 1755-263X. ; 8, s. 50-57
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Tidskriftsartikel (refereegranskat)abstract
- Applying biogeographical insights to the regulation of production forestry and the determination of forest reserve strategies is expected to increase the effectiveness of biodiversity conservation actions. Here, we assess the extent to which such applications take place. By using Sweden as a case study, we demonstrate fundamental differences among biogeographical regions in natural patterns and processes, past land-use, and anthropogenic impacts that need to be better incorporated into strategic conservation planning and decisions. Furthermore, assessment of specific forestry regulations and biogeographical variation in a number of other countries/provinces embracing boreal and temperate biomes also indicate that natural boundaries are insufficiently considered in forest management policies. We suggest that a substantial potential exists to better align conservation priorities with biogeographical characteristics. To illustrate the application of such an approach, we present a decision support model on how forest conservation policies that rest on natural boundaries and ecological processes can be developed.
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| 8. |
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| 9. |
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| 10. |
- Ranius, Thomas, et al.
(författare)
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Dead wood creation to compensate for habitat loss from intensive forestry
- 2014
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Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 169, s. 277-284
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Tidskriftsartikel (refereegranskat)abstract
- Negative consequences of human activities for biodiversity may be mitigated by compensation measures. Although the interest in applying compensation measures is generally increasing, such measures have rarely been applied in forestry. Many boreal forests are managed by clear felling and used for timber and pulp production. There is an increasing interest in intensifying forestry by also harvesting slash and stumps for biofuel at felling. We evaluated the efficiency of combining intensified forestry production with compensation measures, by estimating the net revenue from slash and stump harvest, the cost of high stump creation, and simulating habitat amount for 680 bark- and wood-living species (fungi, beetles, lichens, and bryophytes) in Norway spruce forests in Sweden under different scenarios of biofuel harvest and compensation. We show that the harvest of slash and stumps has a clear negative effect on the habitat amount available for many species, especially for many fungi and beetles. Combining slash harvesting with the creation of high stumps results in an economic surplus and at the same time provides significantly more habitat in comparison with no slash harvesting and no high stump creation. When undertaking stump harvesting it is currently impossible to achieve such positive effects. Thus, our analyses show that compensation can sometimes be a useful tool when both economic and biodiversity goals must be achieved in forestry, but in other cases it is a better alternative to avoid the activity that causes the negative effects. (C) 2013 Elsevier Ltd. All rights reserved.
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