| 1. |
- Ampoorter, Evy, et al.
(författare)
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Tree diversity is key for promoting the diversity and abundance of forest-associated taxa in Europe
- 2020
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 129:2, s. 133-146
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Tidskriftsartikel (refereegranskat)abstract
- Plant diversity is an important driver of diversity at other trophic levels, suggesting that cascading extinctions could reduce overall biodiversity. Most evidence for positive effects of plant diversity comes from grasslands. Despite the fact that forests are hotspots of biodiversity, the importance of tree diversity, in particular its relative importance compared to other management related factors, in affecting forest-associated taxa is not well known. To address this, we used data from 183 plots, located in different forest types, from Mediterranean to Boreal, and established along a climatic gradient across six European countries (FunDivEUROPE project). We tested the influence of tree diversity, tree functional composition (i.e. functional trait values), forest structure, climate and soil on the diversity and abundance/activity of nine taxa (bats, birds, spiders, microorganisms, earthworms, ungulates, foliar fungal pathogens, defoliating insects and understorey plants) and on their overall diversity and abundance/activity (multidiversity, multiabundance/activity). Tree diversity was a key driver of taxon-level and overall forest-associated biodiversity, along with tree functional composition, forest structure, climate and soil. Both tree species richness and functional diversity (variation in functional trait values) were important. The effects of tree diversity on the abundance/activity of forest-associated taxa were less consistent. Nonetheless, spiders, ungulates and foliar fungal pathogens were all more abundant/active in diverse forests. Tree functional composition and structure were also important drivers of abundance/activity: conifer stands had lower overall multidiversity (although the effect was driven by defoliating insects), while stands with potentially tall trees had lower overall multiabundance/activity. We found more synergies than tradeoffs between diversity and abundance/activity of different taxa, suggesting that forest management can promote high diversity across taxa. Our results clearly show the high value of mixed forest stands for multiple forest-associated taxa and indicate that multiple dimensions of tree diversity (taxonomic and functional) are important.
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| 2. |
- Baeten, Lander, et al.
(författare)
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Identifying the tree species compositions that maximize ecosystem functioning in European forests
- 2019
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 56:3, s. 733-744
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Tidskriftsartikel (refereegranskat)abstract
- 1. Forest ecosystem functioning generally benefits from higher tree species richness, but variation within richness levels is typically large. This is mostly due to the contrasting performances of communities with different compositions. Evidence-based understanding of composition effects on forest productivity, as well as on multiple other functions will enable forest managers to focus on the selection of species that maximize functioning, rather than on diversity per se.2. We used a dataset of 30 ecosystem functions measured in stands with different species richness and composition in six European forest types. First, we quantified whether the compositions that maximize annual above-ground wood production (productivity) generally also fulfil the multiple other ecosystem functions (multifunctionality). Then, we quantified the species identity effects and strength of interspecific interactions to identify the "best" and "worst" species composition for multifunctionality. Finally, we evaluated the real-world frequency of occurrence of best and worst mixtures, using harmonized data from multiple national forest inventories.3. The most productive tree species combinations also tended to express relatively high multifunctionality, although we found a relatively wide range of compositions with high- or low-average multifunctionality for the same level of productivity. Monocultures were distributed among the highest as well as the lowest performing compositions. The variation in functioning between compositions was generally driven by differences in the performance of the component species and, to a lesser extent, by particular interspecific interactions. Finally, we found that the most frequent species compositions in inventory data were monospecific stands and that the most common compositions showed below-average multifunctionality and productivity.4. Synthesis and applications. Species identity and composition effects are essential to the development of high-performing production systems, for instance in forestry and agriculture. They therefore deserve great attention in the analysis and design of functional biodiversity studies if the aim is to inform ecosystem management. A management focus on tree productivity does not necessarily trade-off against other ecosystem functions; high productivity and multifunctionality can be combined with an informed selection of tree species and species combinations.
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| 3. |
- Hicks, Lettice C., et al.
(författare)
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The legacy of mixed planting and precipitation reduction treatments on soil microbial activity, biomass and community composition in a young tree plantation
- 2018
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 124, s. 227-235
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Tidskriftsartikel (refereegranskat)abstract
- Drought events are expected to increase as a consequence of climate change, with the potential to influence both plant and soil microbial communities. Mixed planting may be an option to mitigate drought stress to plants, however, the extent to which mixed planting mitigates the indirect effect of drought (reduced plant-derived carbon input) on soil microorganisms remains unknown. Using soils from a young experimental plantation in Central Europe, we investigated whether mixed planting (oak monoculture, and oak admixed with 1–3 other tree species) under simulated drought (50% precipitation reduction for 2 years) influenced soil microbial activity, biomass and community composition. To focus on legacy effects - i.e. indirect effects mediated by plant composition and a history of drought, rather than direct effects of reduced water availability - soils were measured at a standardised moisture content (28 ± 1% water holding capacity). Rates of bacterial growth and respiration were lower in soils with a legacy of drought. In contrast, fungal growth was not affected by a history of drought, suggesting that fungi were less adversely affected by reduced plant-input during drought, compared to bacteria. The effect of drought on the fungal-to-bacterial growth ratio was influenced by mixed planting, leading to a disproportionate decrease in bacterial growth in drought-exposed soils under oak monoculture than when oak was admixed with two or three different tree species. The presence of a particular tree species (with specific functional traits) in the admixture, rather than increased tree richness per se, may explain this response. Microbial biomass parameters, reflecting both the direct and indirect effects of past drought conditions, were consistently lower in drought-exposed soils than controls. While bacteria were more sensitive to the indirect effect of drought than fungi, the biomass concentrations suggested that the direct effect of reduced moisture affected both groups similarly. Overall, our findings demonstrate that drought can have lasting effects on microbial communities, with consequences for microbial function. Results also suggest that admixing oak with other tree species may alleviate the drought-legacy effect on bacteria and increase tolerance to future drought.
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| 4. |
- Rahman, Md Masudur, et al.
(författare)
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Effects of drought legacy and tree species admixing on bacterial growth and respiration in a young forest soil upon drying and rewetting
- 2018
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 127, s. 148-155
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Tidskriftsartikel (refereegranskat)abstract
- In the context of future climate change, the flush of CO2 emissions from soils after drying-rewetting events could have a strong impact on the terrestrial carbon balance. Mixed forests may be more resistant and resilient to drought events compared to monocultures, and as such may modulate the effects of drought on soil functioning belowground. We investigated the influence of mixed planting and drought legacy on respiration and bacterial growth rates (3H Leucine incorporation) in response to drying-rewetting. Soils were sampled from a 7-year old tree diversity experiment (FORBIO), where oak (Quercus robur L.) trees admixed with one or three other tree species were subjected to ∼50% precipitation reduction for 2 years (“drought legacy”). Respiration increased immediately after rewetting, whereas bacterial growth only started after a distinct lag phase of ca. 7 h. A legacy of drought reduced bacterial growth and respiration rates upon rewetting, however tree species admixing did not modulate the drought legacy effect. Our results suggest that prolonged decrease in precipitation may lead to a reduced CO2 pulse upon drying-rewetting and admixing up to three tree species with oak in a young afforestation would not alleviate drought legacy effects on bacterial growth and respiration rates.
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