| 1. |
- Kattge, Jens, et al.
(författare)
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TRY plant trait database - enhanced coverage and open access
- 2020
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Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
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Tidskriftsartikel (refereegranskat)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
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| 2. |
- Nordin, Per
(författare)
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Regeneration measures in time and space : Site preparation, planting and digital tools
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Regeneration success depends on decisions made based on factors on aregional, site, and microenvironmental level. Therefore, understanding andmapping of such factors between and within sites can guide decisions forbetter seedling establishment. Thus, the aim of this thesis was to findcombinations of regeneration measures that result in low seedling mortalityand high growth. Additionally, to explore the potential of digital tools inregeneration planning. Aims were handled using field experiments and asurvey, by integrating digital tools in the analysis and experimental set-up.Increased precipitation and decreased air temperatures between April andOctober during the planting year lowered seedling mortality. Planting inmineral soil also lowered the mortality rate, which emphasized theimportance of planting and site preparation quality (Paper I). Selection ofsite preparation method was found to be of minor importance. The sitepreparation’s ability to create suitable planting spots was most important forseedling survival and growth. Selection of site preparation affected soildisturbance, and natural regeneration was promoted with all methods usedin the experiments (Paper II). Adapting planting position choice, followingsite preparation, to within-site variation was valuable to decrease mortalityrates and promote growth (Paper II-III). In wet conditions, elevatedplanting positions were advantageous compared to lower ones, but moreflexibility could be applied in drier conditions. Norway spruce, Scots pine,and silver birch reacted differently to planting position choice (Paper III).Paper I-III indicated that digital tools could be used in regenerationplanning. A depth-to-water-raster successfully explained seedling mortalityand growth in the extreme ends of the soil moisture spectrum. Using remotesensing derived variables can be valuable for further mapping andunderstanding of between and within-site variation in future regenerationplanning. There were no long-term negative effects on stand productivityafter 30 years following site preparation. The standing volume was largestafter ploughing but disc trenching and mounding also had higher standingvolume than the unscarified control (Paper IV). I conclude that regenerationdecisions made today, regarding species selection and regeneration method,should strive for increased precision for the benefit of the forests oftomorrow.
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| 3. |
- Thiffault, Nelson, et al.
(författare)
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Mechanical Site Preparation Across Space and Time: A Trans-Atlantic Perspective on Successful Regeneration of Boreal Forests
- 2024
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Ingår i: Presented at IUFRO World congress 2024. Forests & Society Towards 2050.
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Konferensbidrag (refereegranskat)abstract
- Successful forest regeneration is crucial for sustainable forest management. In boreal contexts, plantation forestry is notably used when natural regeneration is insufficient after harvesting or wildfires, but planted seedlings face various stresses on harvested sites, jeopardizing their survival and growth. Limited access to water, nutrients and light, plus exposure to pests, and diseases contribute to these stresses. Mechanical site preparation, disturbing the organic layer and upper mineral soil through techniques such as discing, mounding or inverting, is commonly used to mitigate post-planting stress. However, climate change, social interest in forest management, and the need to procure diverse ecosystem services require precise silviculture practices tailored to regional and local objectives. Our empirical research in boreal ecosystems of North America and Scandinavia reveals intricate interactions affecting seedling establishment after reforestation. For instance, in boreal Quebec, Canada, successful conifer seedling establishment depends on regional precipitation, temperature, and interactions with soil characteristics and microsite conditions. In Sweden, planting position within scarified sites significantly influences conifer seedling survival, but effects vary with soil moisture. Long-term silviculture studies also demonstrate the importance of early treatments for stand productivity. For example, mechanical site preparation significantly enhances seedling growth and survival, impacting sapling growth even after 18 years in boreal Quebec. We have observed that seedlings planted in scarified plots show improved water use efficiency compared to control plots. Also, we have shown that site preparation effects on standing volume and density persist for at least 30 years in Sweden. In conclusion, our empirical studies with Pinus and Picea species across multiple sites in Canada and Sweden highlight the absence of a universal solution for regeneration success in boreal ecosystems. Forest managers and decision-makers must recognize these complex interactions and support further international research collaborations. The success of large-scale forest landscape restoration and reforestation programs depends on implementing regionally tailored silviculture prescriptions based on an understanding of the mechanisms driving seedling responses.
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