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Genotypic responses to different environments and reduced precipitation reveal signals of local adaptation and phenotypic plasticity in woodland strawberry
No full textBackground and Aims Climate change is causing increasing temperatures and drought, creating new environmental conditions, which species must cope with. Plant species can respond to these shifting environments by escaping to more favourable environments, undergoing adaptive evolution or exhibiting phenotypic plasticity. In this study, we investigate genotype responses to variation in environmental conditions (genotype-by-environment interactions) over multiple years to gain insights into the plasticity and potential adaptive responses of plants to environmental changes in the face of climate change.Methods We transplanted 16 European genotypes of Fragaria vesca (Rosaceae), the woodland strawberry, reciprocally between four sites along a latitudinal gradient from 40 degrees N (Spain) to 70 degrees N (northern Finland). We examined genotype-by-environment interactions in plant performance traits (fruit and stolon production and rosette size) in ambient weather conditions and a reduced precipitation treatment (as a proxy for drought) at these sites over 2 years.Key Results Our findings reveal signals of local adaptation for fruit production at the latitudinal extremes of F. vesca distribution. No clear signals of local adaptation for stolon production were detected. Genotypes from higher European latitudes were generally smaller than genotypes from lower latitudes across almost all sites, years and both treatments, indicating a strong genetic control of plant size in these genotypes. We found mixed responses to reduced precipitation: several genotypes exhibited poorer performance under the reduced precipitation treatment across most sites and years, with the effect being most pronounced at the driest site, whereas other genotypes responded to reduced precipitation by increasing fruit and/or stolon production and/or growing larger across most sites and years, particularly at the wettest site.Conclusions This study provides insights into the influence of different environments on plant performance at a continental scale. Although woodland strawberry seems locally adapted in more extreme environments, reduced precipitation results in winners and losers among its genotypes. This might ultimately reduce genetic variation in the face of increasing drought frequency and severity, with implications for the capacity of the species to adapt
Soil carbon and nitrogen near alder, birch and spruce trees in four mixed Norway spruce-dominated stands
No full textTo increase understanding of soil processes in mixed forests, we examined soil nitrogen (N) and carbon (C) near alder, birch and spruce trees in Norway spruce (Picea abies)-dominated stands in southern Finland. Two sites were middle-fertile stands aged 20-40 years, and the other two were fertile stands aged 60 years. Grey alder (Alnus incana) was present at all sites and birch (Betula pendula and Betula pubescens) was present at three sites. At each site, we determined C and N stocks of forest floor and mineral soil (0-10 cm depth) close to (max distance 1.5 m) alder, birch, and spruce trees. We found forest floor C stocks to be 0.8 kg m- 2 higher under alder than under birch trees. Forest floor N stocks were higher near alder than near birch or spruce. Alder decreased C:Nratio of both forest floor and mineral soil by around 5 units compared to spruce; birch decreased C:N-ratio of mineral soil. Diffusive fluxes of soil N, as determined by microdialysis method, showed no significant differences between species. At the two fertile 60-year-old stands, microbial biomass N was lower near alder than near birch, birch decreased microbial biomass C:N-ratio compared to spruce, and alder decreased C mineralisation rate and dissolved organic C concentration compared to spruce. Several other properties, such as the concentrations of monoterpenes and condensed tannins, were unexpectedly similar under alder, birch and spruce trees. This suggests the presence of complex interactions between trees in mixed forests, driven by above- and belowground processes involving litter dispersal
Genetic Analysis of Apple Autumn Canopy Senescence in a Nordic Climate
No full textAutumn phenology traits are likely to be essential for the adaptation of apple to boreal climate. However, the genetic control of these traits is not well understood, and, for example, growth cessation does not appear to be controlled by day length as in many other boreal tree species. Here, I combine a quantitative genetic and population genomic approach to study autumn senescence in apple. I phenotyped a diverse germplasm collection for the timing of autumn senescence, performed quantitative trait loci (QTL) mapping in a multiparental population (MPP), and investigated genomic signals of selection to identify candidate genes. The timing of 50% autumn senescence was negatively correlated with adaptation to higher (boreal) climate zones. Two QTL were found to control the timing of autumn senescence in the MPP, exhibiting both dominance and epistatic interactions. The QTL on linkage group (LG) 17 was also variable in the diversity germplasm, while the QTL on LG11 was not. Cultivars adapted to boreal climate showed weak signals of selection at two loci within the genomic region of chromosome 17 corresponding to the LG17 QTL interval, consistent with a recent expansion to northern Sweden. These loci coincide with two predicted UGT85 genes and a possible copy number variation in PHYC, respectively. Thus, this study provides valuable information for further research and breeding of apple in light of the ongoing climate change
Bridging spatio-temporal gaps in ALS data using Landsat time series and forest disturbance-recovery metrics via multi-task neural networks
No full textEuropean forests contribute to climate change mitigation by sequestering carbon, conserving biodiversity, and enhancing water retention. However, climate-induced disturbances such as fires, windthrows, droughts, and pest outbreaks underscore the need for stronger forest monitoring systems. National Forest Inventories (NFIs) serve as the primary source of forest data and information in Europe. Yet, inconsistencies in timing, coverage, methodologies, and data quality highlight the need for a more harmonized and spatially detailed approach. Critically, predicting forest variables directly from satellite data remains challenging, mainly due to the difficulties in aligning remote sensing with ground data. Meanwhile, the operational use of airborne laser scanning (ALS) data is limited by high costs, infrequent updates, and inconsistent coverage from different sensors and flight conditions. This study presents a novel approach relying on fully connected neural networks to integrate Landsat satellite time series and forest disturbance and recovery metrics with ALS data to predict forest height metrics, which can then be used to accurately predict critical forest variables, such as growing stock volume (GSV) and stand basal area (BA). The method was tested across five ecologically and geographically diverse European forest regions: Tuscany (Italy), the Netherlands, the Canton of Grisons (Switzerland), Bia & lstrok;owiez(center dot)a Forest (Poland), and the Vindelalven-Juhttatahkka Biosphere Reserve (Sweden). ALS forest height metrics were predicted with R2 values ranging from 0.47 to 0.68. Then, based on field data, forest height metrics were used to predict GSV (R2 = 0.78) and BA (R2 = 0.69). Our method addresses the issue of limited spatial and temporal availability of ALS data by predicting ALSderived height metrics using Landsat time series. This study examines the challenges of combining satellite and NFI data, building on the premise that satellite data can be effectively used to predict forest height metrics derived from ALS, which in turn can be used to accurately quantify several forest variables. The methods presented here support scalable and cost-effective forest monitoring by providing the spatially and temporally detailed information needed to implement climate-smart forestry
Bird and bat diversity, herbivory and trade-offs with yield in coffee agroforests in Arabica coffee's native range
No full textAgroforestry systems have the potential to provide benefits for conservation, natural pest control and farmer livelihoods. Yet, we need a clearer understanding of how environmental drivers shape different components of biodiversity, how these biodiversity components contribute to suppressing pest levels, and how biodiversity trades off with yield. We focused on the diversity and role of birds and bats across different types of coffee farms in Arabica coffee's native range in southwestern Ethiopia. While elevation, canopy cover, shade tree community composition and surrounding forest cover did not explain bird and bat species richness, the composition of the bird and bat community was significantly influenced by the composition of the shade tree community. Herbivory was unrelated to the species richness and community composition of insectivorous birds and bats. We found no trade-off between bird and bat species richness and coffee yield, but the composition of the bird, but not bat, community changed with increasing yield, where forest specialist birds rapidly declined in abundance from low to mid-yielding sites. Overall, we suggest that the similar levels of bird and bat species richness and an absence of a relationship with herbivory across different types of agroforests are due to the diverse mosaic agricultural landscape and lack of agroforests with very high management intensities (which are common in other parts of the world). From a conservation point of view, intensification of coffee management in the lowest-yielding sites would threaten biodiversity in terms of forest specialist birds. However, is it also important to learn more on the potential positive roles of biodiversity in those parts of the landscape where coffee is managed for high yields. From both a conservation and sustainable management point of view we urgently need more insights into the taxonomy, life-history, habitat preferences and foraging ranges of East African bats
Commodity risk assessment of Alnus cordata and Alnus glutinosa specimen trees from the UK
No full textThe European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'high risk plants, plant products and other objects'. This Scientific Opinion covers the plant health risks posed by the following commodities: Alnus cordata and A. glutinosa as specimen trees (from 7 to 25 years old) in pots imported into the EU from the UK. A list of pests potentially associated with the commodities was compiled. The relevance of each pest was assessed based on evidence following defined criteria. Three pests were selected for further evaluation: one EU-protected zone quarantine pest (Entoleuca mammata), one EU quarantine pest (Phytophthora ramorum (non-EU isolates)) and one non-quarantine pest (Phytophthora siskiyouensis). For the selected pests, the risk mitigation measures implemented in the UK and specified in the technical dossier were evaluated. For these pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, as larger trees are more likely to be infested mainly due to longer time grown in the field. In addition, large canopies and root systems are more difficult to inspect, thereby making the detection of pests more challenging on large trees. The degree of pest freedom varies between the pests evaluated, with E. mammata being the pest most frequently expected on imported Alnus spp. specimen trees. Expert Knowledge Elicitation indicated, with 95% certainty, that between 9905 and 10,000 per 10,000 Alnus spp. specimen trees would be free from E. mammata
Effects of Linear Openings in Forests on Temperate Bird Communities
No full textNarrow, unpaved forest roads and paths are a ubiquitous feature of managed forest landscapes worldwide, with the potential to influence bird communities. However, compared to large roads, the effects of structural changes to the understory and canopy generated by unpaved forest roads and paths are less understood. In this study, we investigate the influence of narrow linear openings in the forest caused by forest roads and paths on bird communities in the southern Black Forest, Germany. We surveyed bird communities in four distinct plot types, including two "linear openings": forest interior, forest paths, forest roads, and forest edges. Forest roads and paths were expected to represent intermediate conditions in terms of openness between interior forests and a forest edge. We aim to understand how these linear openings affect birds' species richness, community composition, and functional traits. Our results show that while species richness remains similar among plot types, the community composition at forest edges differs. The indicator analysis reveals indicator species for each type of plot. In addition, functional traits like body mass and wing shape showed a weak response to the linear openings. The findings suggest that although unpaved forest roads and paths potentially introduce resources and structural modifications in the forest structure, the effect on the birds seems limited compared to pronounced habitat transitions, such as forest edges. These narrow linear infrastructures are often necessary for forest use by humans and can be unnoticeable for birds when carefully planned on a small scale. Nevertheless, forest managers should not overlook broader-scale effects (e.g., potential habitat loss, predation). Our findings contribute to a better understanding of birds' responses to linear and small-scale fragmentation introduced by unpaved forest roads and paths. However, more research is needed to distinguish the ecological impacts and management implications for bird communities in temperate managed forests along a gradient of linear openness
Terrestrial carbon inputs drive methylmercury accumulation in zooplankton of boreal and subarctic lakes
No full textBoreal and subarctic lakes are subject to the climate-sensitive process of browning, whereby transport of terrestrial dissolved organic matter (tDOM) to lakes results in greater dissolved organic carbon (DOC) concentrations and associated darker water color. Increasing tDOM will increase mercury (Hg) transport to these lakes, but whether this leads to greater methylHg (MeHg) bioaccumulation in food webs remains unclear. We determined whether increasing DOC increased MeHg bioaccumulation in the lower food web (i.e., zooplankton) by measuring a suite of water chemistry characteristics (including aqueous MeHg and DOC) along with stable isotopes of C (delta 13C) and N (delta 15N), fatty acid (FA) profiles, and MeHg content of zooplankton from 16 Scandinavian boreal and subarctic lakes along a DOC gradient in the Fall of 2016. We found that both aqueous and zooplankton MeHg were positively correlated with DOC concentration, and that DOC and zooplankton MeHg both increased with the bacterial FA marker 18:1n-7 and decreased with docosahexaenoic acid (DHA) : arachidonic acid and DHA : eicosapentaenoic acid ratios in zooplankton, which are indicators of diet or taxonomic composition. Zooplankton MeHg content was best predicted by delta 13C and the FA 18:1n-7, indicating that zooplankton MeHg bioaccumulation in zooplankton was associated with changes in their resource use along a DOC gradient. Our results suggest that lake browning will likely lead to an increase in MeHg bioaccumulation in zooplankton by affecting aqueous MeHg exposure and lower food web dynamics. In turn, this may lead to increased MeHg contamination in fish and other wildlife
Pedoclimatic, knowledge and management factors drive European soybean and faba bean yields
No full textThe low usage of grain legumes in European cropping systems is often attributed to yield gaps due to limiting pedoclimatic conditions, sub-optimal management practices, and farmers' limited experience and knowledge in growing these crops. The relative contributions of these factors to current grain legume yield gaps at European scale and, in particular, the difference between yields achieved by experienced farmers and those achieved by novices remain unknown. We therefore explored the relationship between yields and these different factors, to identify areas where farmers require more support to close the yield gaps in grain legume production. To this purpose, we conducted a large-scale online farmer survey in nine European countries with a focus on soybean and faba bean. For both crops, classification and regression tree analysis identified country of production as the primary explanatory variable of yield variation and confirmed the hypothesis that greater experience and knowledge is associated with higher yields. However, the effect of several factors differed between the crops, showing the need for legume-specific strategies. Experience and knowledge were particularly important for soybean, although also relevant for faba bean in low-yielding environments. Other important factors identified to determine yield for soybean included farm specialization, agroclimatic zone, the number of years growing grain legumes and the size of farmland, while for faba bean these important factors were pest management and perceived soil fertility. Farmers highlighted drought, weed infestation, and soil characteristics as having critical impacts on yields for both crops, as well as inoculation and irrigation for soybean. Both soybean and faba bean growers emphasized the need for more information on plant protection and cultivar selection. The results indicate the potential to increase legume yields by supporting farmers in the first years of growing grain legumes, especially for crops that have a shorter history in Europe such as soybean