| 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. |
- Senty, Paul, et al.
(författare)
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Fast Fusion of Sentinel-2 and Sentinel-3 Time Series over Rangelands
- 2024
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Ingår i: Remote Sensing. - 2072-4292. ; 16:11
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Tidskriftsartikel (refereegranskat)abstract
- Monitoring ecosystems at regional or continental scales is paramount for biodiversity conservation, climate change mitigation, and sustainable land management. Effective monitoring requires satellite imagery with both high spatial resolution and high temporal resolution. However, there is currently no single, freely available data source that fulfills these needs. A seamless fusion of data from the Sentinel-3 and Sentinel-2 optical sensors could meet these monitoring requirements as Sentinel-2 observes at the required spatial resolution (10 m) while Sentinel-3 observes at the required temporal resolution (daily). We introduce the Efficient Fusion Algorithm across Spatio-Temporal scales (EFAST), which interpolates Sentinel-2 data into smooth time series (both spatially and temporally). This interpolation is informed by Sentinel-3’s temporal profile such that the phenological changes occurring between two Sentinel-2 acquisitions at a 10 m resolution are assumed to mirror those observed at Sentinel-3’s resolution. The EFAST consists of a weighted sum of Sentinel-2 images (weighted by a distance-to-clouds score) coupled with a phenological correction derived from Sentinel-3. We validate the capacity of our method to reconstruct the phenological profile at a 10 m resolution over one rangeland area and one irrigated cropland area. The EFAST outperforms classical interpolation techniques over both rangeland (−72% in the mean absolute error, MAE) and agricultural areas (−43% MAE); it presents a performance comparable to the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) (+5% MAE in both test areas) while being 140 times faster. The computational efficiency of our approach and its temporal smoothing enable the creation of seamless and high-resolution phenology products on a regional to continental scale.
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| 3. |
- Wang, Lanhui, et al.
(författare)
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Tree cover and its heterogeneity in natural ecosystems is linked to large herbivore biomass globally
- 2023
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Ingår i: One Earth. - 2590-3330. ; 6, s. 1759-1770
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Tidskriftsartikel (refereegranskat)abstract
- Addressing intertwined crises of climate change and biodiversity loss is a pressing global challenge, with trees playing pivotal roles in promoting carbon sequestration and habitat diversity. However, there is a distinct knowledge gap concerning the global drivers shaping tree cover and its heterogeneity, particularly the roles and relative importance of large herbivores and fire compared to climatic and topo-edaphic conditions. Here, we deploy satellite observations of strictly protected areas worldwide to reveal that in regions where vegetation may be in disequilibrium with climate, high biomass of large herbivores, especially browsers, is inversely related to tree cover but positively associated with its spatial heterogeneity. Conversely, fire reduces both tree cover and heterogeneity. These results suggest that top-down megafauna effects on landscape-scale vegetation openness and heterogeneity manifest worldwide. Our finding supports the need to consider megafauna, particularly large herbivores, in ecosystem effects on climate change mitigation and conservation and restoration efforts through trophic rewilding.
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