| 2. |
- Eckstein, Rolf Lutz, et al.
(författare)
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Invasibility of a Nutrient-Poor Pasture through Resident and Non-Resident Herbs Is Controlled by Litter, Gap Size and Propagule Pressure
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:7
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Tidskriftsartikel (refereegranskat)abstract
- Since inference concerning the relative effects of propagule pressure, biotic interactions, site conditions and species traits on the invasibility of plant communities is limited, we carried out a field experiment to study the role of these factors for absolute and relative seedling emergence in three resident and three non-resident confamilial herb species on a nutrient-poor temperate pasture. We set up a factorial field experiment with two levels each of the factors litter cover (0 and 400 g m(-2)), gap size (0.01 and 0.1 m(2)) and propagule pressure (5 and 50 seeds) and documented soil temperature, soil water content and relative light availability. Recruitment was recorded in spring and autumn 2010 and in spring 2011 to cover initial seedling emergence, establishment after summer drought and final establishment after the first winter. Litter alleviated temperature and moisture conditions and had positive effects on proportional and absolute seedling emergence during all phases of recruitment. Large gaps presented competition-free space with high light availability but showed higher temperature amplitudes and lower soil moisture. Proportional and absolute seedling recruitment was significantly higher in large than in small gaps. In contrast, propagule pressure facilitated absolute seedling emergence but had no effects on proportional emergence or the chance for successful colonisation. Despite significantly higher initial seedling emergence of resident than non-resident species, seed mass and other species-specific traits may be better predictors for idiosyncratic variation in seedling establishment than status. Our data support the fluctuating resource hypothesis and demonstrate that the reserve effect of seeds may facilitate seedling emergence. The direct comparison of propagule pressure with other environmental factors showed that propagule pressure affects absolute seedling abundance, which may be crucial for species that depend on other individuals for sexual reproduction. However, propagule batch size did not significantly affect the chance for successful colonisation of disturbed plots.
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| 3. |
- Lerink, Bas J. W., et al.
(författare)
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How much wood can we expect from European forests in the near future?
- 2023
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Ingår i: Forestry (London). - : Oxford University Press. - 0015-752X .- 1464-3626. ; 96:4, s. 434-447
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Tidskriftsartikel (refereegranskat)abstract
- The demand for wood in Europe is expected to increase in the coming decades. However, any theoretical maximum supply will be affected by sustainability constraints, the motivations of forest owners and regional factors, such as incentives, species and assortments. However, the influence of these factors on supply is changeable. In this study, we quantify what might be realistically available as additional wood supply from currently existing European forests, based on a combination of results of the forest resource model EFISCEN-Space and a literature review of national supply projections. Wood mobilization scenarios for 10 representative Model Regions in Europe that assume forest owners and managers in the simulated regions will adapt their behaviour to alternative behaviour as recorded from other regions were projected with the EFISCEN-Space model. The realistic additional potential based on the literature review is 90 million m(3) yr(-1). This potential should be attainable within 10-20 years. However, the simulations in the Model Regions found potentials to be lower in 7 out of 10 cases as compared with the country they are located in. On average, the model regions reached less than half of the potential as compared with the literature review. This suggests that the realistic additional potential at the European scale may well be lower if all mobilization barriers are taken into account in more detail, but also highlights the uncertainty surrounding these estimates. We conclude from the analyses that although there are large differences in potential between regions and the analysis method employed, there are no 'hotspots' where a large pool of accessible wood can be quickly mobilized using existing infrastructure for nearby industries. An increase in harvest would therefore only be possible with a large effort that spans the whole chain, from forest owners' behaviour to capacity building, financial incentives and matching resources to harvesting capacity. The additionally available wood can most likely only be mobilized against higher marginal costs and will thus only become available in times of higher stumpage prices. The largest potential lies in privately owned forests which often have a fragmented ownership but will most likely be able to supply more wood, though mostly from deciduous species. In the long term (more than 20 years), additional wood, compared with the amounts we found for short term, can only be made available through investments in afforestation, forest restoration, improved forest management and more efficient use of raw material and recycled material.
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