Kreyling J., Grant K., Hammerl V., Arfin-Khan M.A.S., Malyshev A.V., Peñuelas J., Pritsch K., Sardans J., Schloter M., Schuerings J., Jentsch A., Beierkuhnlein C. (2019) Winter warming is ecologically more relevant than summer warming in a cool-temperate grassland. Scientific Reports. 9: 0-0.EnllaçDoi: 10.1038/s41598-019-51221-w
Climate change affects all seasons, but warming is more pronounced in winter than summer at mid- and high latitudes. Winter warming can have profound ecological effects, which are rarely compared to the effects of summer warming, and causal explanations are not well established. We compared mild aboveground infrared warming in winter to warming in summer in a semi-natural, cool-temperate grassland in Germany for four years. Aboveground plant biomass increased following winter warming (+18%) and was unaffected by summer warming. Winter warming affected the composition of the plant community more than summer warming, favoring productive species. Winter warming increased soil respiration more than summer warming. Prolonged growing seasons and changes in plant-community composition accounted for the increased aboveground biomass production. Winter warming stimulated ecological processes, despite causing frost damage to plant roots and microorganisms during an extremely cold period when warming reduced the thermal insulation provided by snow. Future warming beyond such intermittent frosts may therefore further increase the accelerating effects of winter warming on ecological processes. © 2019, The Author(s).
Lang A., Kallhardt F., Lee M.S., Loos J., Molander M.A., Muntean I., Pettersson L.B., Rákosy L., Stefanescu C., Messéan A. (2019) Monitoring environmental effects on farmland Lepidoptera: Does necessary sampling effort vary between different bio-geographic regions in Europe?. Ecological Indicators. 102: 791-800.EnllaçDoi: 10.1016/j.ecolind.2019.03.035
In agro-ecosystems, environmental monitoring is fundamental to detect and survey changes related to land use change and management practices. Butterflies and moths have often been suggested as suitable indicators for monitoring environmental effects on biodiversity in farmlands. Here, we estimated the required sample size and monitoring effort necessary to run a Lepidoptera survey in European farmland, assessing in particular if monitoring investment would differ between representative bio-geographical regions. We operated linear 1-km long transect routes in farmland of Romania, Spain and Sweden from 2013 to 2015, and recorded butterflies and burnet moths (Papilionoidea, Zygaenidae). The transects were walked back and forth four times a season, and replicated yearly. The lepidopteran diversity was high in farmlands of Romania and Spain, but comparatively low in Sweden. The coefficient of variation (CV) of recorded species number differed between countries being lowest in Sweden and highest in Spain. In general, the CV dropped above a transect length of 400–800 m, thus indicating an increase in statistical power. Assuming a non-parametric test for matched samples, power calculations were conducted with the raw count data and with log-transformed count data for comparison. When using log-transformed data, the required sample size to detect an effect was less than 10 transects per country or region (in order to detect a 10% loss of species or a decrease of 30% in total abundance). Specific subgroups of species, e.g. protected species or specific indicator groups, showed a higher variance, thus requiring a higher sample size to detect effects ranging from 12 to 16 transects (equivalent to 21–29 working days per country and year). When using original, untransformed count data a considerably larger sample size would be needed. Actual time to be invested in field work differed between countries due to contrasting regional constraints and conditions. Nevertheless, the final monitoring effort in working days was similar between countries as the factors involved balanced out each other, in particular due to the differing year-to-year variations. Our study demonstrated the feasibility of an environmental monitoring programme in arable land using farmland butterflies across Europe. We present a suitable approach and guidelines as well as the necessary effort to be invested in future Europe-wide monitoring programmes of butterflies in agro-ecosystems, based on predictions of statistical power. © 2019
Lanzas M., Hermoso V., de-Miguel S., Bota G., Brotons L. (2019) Designing a network of green infrastructure to enhance the conservation value of protected areas and maintain ecosystem services. Science of the Total Environment. 651: 541-550.EnllaçDoi: 10.1016/j.scitotenv.2018.09.164
There is a growing demand for holistic landscape planning to enhance sustainable use of ecosystem services (ESS) and maintenance of the biodiversity that supports them. In this context, the EU is developing policy to regulate the maintenance of ESS and enhance connectivity among protected areas (PAs). This is known as the network of Green Infrastructure (GI). However, there is not a working framework defined to plan the spatial design of such network of GI. Here, we use the software Marxan with Zones, to prioritize the spatial distribution of different management zones that accommodate the needs of a network of GI. These zones included a conservation zone, mainly devoted to protecting biodiversity, a GI zone, that aimed at connecting PAs and maintaining regulating and cultural ESS; and a management zone devoted to exploiting provisioning ESS. We performed four planning scenarios that distribute the targets for ESS and biodiversity in different ways across management zones. We also conducted a sensitivity analysis by increasing ESS targets to explore trade-offs that may occur when managing together biodiversity and ESS. We use Catalonia (northeastern Spain) as a case study. We found that the representation of ESS could be achieved for intermediate targets in all scenarios. There was, however, a threshold on these targets over which trade-offs appeared between maintaining regulating and cultural ESS and biodiversity versus getting access to provisioning ESS. These “thresholds values” were displaced towards higher ESS targets when we moved from more strict to more flexible planning scenarios (i.e., scenarios that allowed mixing representation of objectives for biodiversity and ESS within the same zone). This methodological approach could help design a framework to integrate biodiversity and ESS management in holistic plans and decision making and, at the same time, meeting European mandates concerning the design of GI networks, or similar needs elsewhere. © 2018 Elsevier B.V.
Lehikoinen A., Brotons L., Calladine J., Campedelli T., Escandell V., Flousek J., Grueneberg C., Haas F., Harris S., Herrando S., Husby M., Jiguet F., Kålås J.A., Lindström Å., Lorrillière R., Molina B., Pladevall C., Calvi G., Sattler T., Schmid H., Sirkiä P.M., Teufelbauer N., Trautmann S. (2019) Declining population trends of European mountain birds. Global Change Biology. 25: 577-588.EnllaçDoi: 10.1111/gcb.14522
Mountain areas often hold special species communities, and they are high on the list of conservation concern. Global warming and changes in human land use, such as grazing pressure and afforestation, have been suggested to be major threats for biodiversity in the mountain areas, affecting species abundance and causing distribution shifts towards mountaintops. Population shifts towards poles and mountaintops have been documented in several areas, indicating that climate change is one of the key drivers of species’ distribution changes. Despite the high conservation concern, relatively little is known about the population trends of species in mountain areas due to low accessibility and difficult working conditions. Thanks to the recent improvement of bird monitoring schemes around Europe, we can here report a first account of population trends of 44 bird species from four major European mountain regions: Fennoscandia, UK upland, south-western (Iberia) and south-central mountains (Alps), covering 12 countries. Overall, the mountain bird species declined significantly (−7%) during 2002–2014, which is similar to the declining rate in common birds in Europe during the same period. Mountain specialists showed a significant −10% decline in population numbers. The slope for mountain generalists was also negative, but not significantly so. The slopes of specialists and generalists did not differ from each other. Fennoscandian and Iberian populations were on average declining, while in United Kingdom and Alps, trends were nonsignificant. Temperature change or migratory behaviour was not significantly associated with regional population trends of species. Alpine habitats are highly vulnerable to climate change, and this is certainly one of the main drivers of mountain bird population trends. However, observed declines can also be partly linked with local land use practices. More efforts should be undertaken to identify the causes of decline and to increase conservation efforts for these populations. © 2018 John Wiley & Sons Ltd
Liu L., Estiarte M., Peñuelas J. (2019) Soil moisture as the key factor of atmospheric CH4 uptake in forest soils under environmental change. Geoderma. 355: 0-0.EnllaçDoi: 10.1016/j.geoderma.2019.113920
Methane (CH4) is an important anthropogenic greenhouse gas that can be produced and consumed by microorganisms in soils. We present a meta-analysis of the potential effects of environmental change on CH4 uptake by forest soils. Such effects have not been reliably estimated even though aerobic methanotrophs in forest soils are the largest biological sink for atmospheric CH4. Differences in the annual rate of CH4 uptake between forests are likely caused by differences in vegetation, microbial communities, and the physical and chemical properties of soil environments, but we found no clear different patterns at annual scale among tropical, temperate, and boreal forests. The meta-analysis indicated that the rates of CH4 uptake in forest ecosystems were significantly decreased under elevated CO2 and N enrichment, but the rates increased under drought. The effects of warming on the rates of CH4 uptake were inconsistent in forest soils, and the response ratio accordingly suggested that a warmer climate would have no significant effect on the rate of CH4 uptake. The seasonality of CH4 uptake in natural forest soils and the clear results of the drought experiments evidence the importance of soil moisture. However, our linear model did not unravel a clear negative effect of climatic water surplus nor mean annual precipitation on soil CH4 uptake. Therefore, process-based and ecosystem-specific models of CH4 flux are also warranted for predicting the responses of ecosystemic CH4 fluxes to climate change. © 2019 Elsevier B.V.
Liu Q., Piao S., Fu Y.H., Gao M., Peñuelas J., Janssens I.A. (2019) Climatic Warming Increases Spatial Synchrony in Spring Vegetation Phenology Across the Northern Hemisphere. Geophysical Research Letters. 46: 1641-1650.EnllaçDoi: 10.1029/2018GL081370
Climatic warming has advanced spring phenology across the Northern Hemisphere, but the spatial variability in temperature sensitivity of spring phenology is substantial. Whether spring phenology will continue to advance uniformly at latitudes has not yet been investigated. We used Bayesian model averaging and four spring phenology models, and demonstrated that the start of vegetation growing season across the Northern Hemisphere will become substantially more synchronous (up to 11.3%) under future climatic warming conditions. Larger start of growing season advances are expected at higher than lower latitudes (3.7–10.9 days earlier) due to both larger rate in spring warming at higher latitudes and larger decreases in the temperature sensitivity of start of growing season at low latitudes. The consequent impacts on the northern ecosystems due to this increased synchrony may be considerable and thus worth investigating. ©2019. American Geophysical Union. All Rights Reserved.
Lucas-Borja M.E., Plaza-Álvarez P.A., Gonzalez-Romero J., Sagra J., Alfaro-Sánchez R., Zema D.A., Moya D., de las Heras J. (2019) Short-term effects of prescribed burning in Mediterranean pine plantations on surface runoff, soil erosion and water quality of runoff. Science of the Total Environment. 674: 615-622.EnllaçDoi: 10.1016/j.scitotenv.2019.04.114
Fires are a complex phenomenon that may generate a chain of responses and processes that affect each part of the ecosystem. Thus, it is important to understand the magnitude of the impacts of fire on soil properties and the response of plants to this disturbance. For the moment, few studies have examined the effects of prescribed fire on large plots in afforested pine plantations in Mediterranean ecosystems. To fill this gap, the effects of a prescribed fire on runoff, soil erosion, and water quality for approximately one year after burning have been evaluated in pine plantations in south-eastern Spain. We constructed six erosion plots in the control area and six erosion plots in the burned area that were 4 m long and 2 m wide, immediately after the prescribed fire. Runoff, soil erosion and runoff water quality were studied after each rainy event in all plots. Our results reveal that prescribed fire did not significantly affect runoff and soil erosion when low intensity precipitations occur at pine plantations. In relation to water quality, water turbidity, salinity, pH, organic matter content and ionic substances concentrations increased immediately after prescribed burn, nevertheless these changes disappeared over time. We can conclude that prescribed fire can be a useful tool for fuel reduction in Mediterranean pine plantations without wide and long-term impacts to soil losses, or water quality. © 2019 Elsevier B.V.
Luyssaert S., Marie G., Valade A., Chen Y.-Y., Djomo S.N., Ryder J., Otto J., Naudts K., Lansø A.S., Ghattas J., McGrath M.J. (2019) Author Correction: Trade-offs in using European forests to meet climate objectives (Nature, (2018), 562, 7726, (259-262), 10.1038/s41586-018-0577-1). Nature. 567: 0-0.EnllaçDoi: 10.1038/s41586-019-1023-8
In this Letter, in “About 75% of this reduction is expected to come from emission reductions and the remaining 25% from land use, land-use change and forestry”, ‘25%’ should read ‘1%’ and '75%' should read '99%'. In the sentence “The carbon-sink-maximizing portfolio has a small negative effect on annual precipitation (−2 mm) and no effect on air temperature (Table 1)” the word ‘precipitation’ was omitted. Denmark was accidentally deleted during the conversion of Fig. 1. The original Letter has been corrected online. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
Marañón-Jiménez S., Peñuelas J., Richter A., Sigurdsson B.D., Fuchslueger L., Leblans N.I.W., Janssens I.A. (2019) Coupled carbon and nitrogen losses in response to seven years of chronic warming in subarctic soils. Soil Biology and Biochemistry. 134: 152-161.EnllaçDoi: 10.1016/j.soilbio.2019.03.028
Increasing temperatures may alter the stoichiometric demands of soil microbes and impair their capacity to stabilize carbon (C) and retain nitrogen (N), with critical consequences for the soil C and N storage at high latitude soils. Geothermally active areas in Iceland provided wide, continuous and stable gradients of soil temperatures to test this hypothesis. In order to characterize the stoichiometric demands of microbes from these subarctic soils, we incubated soils from ambient temperatures after the factorial addition of C, N and P substrates separately and in combination. In a second experiment, soils that had been exposed to different in situ warming intensities (+0, +0.5, +1.8, +3.4, +8.7, +15.9 °C above ambient) for seven years were incubated after the combined addition of C, N and P to evaluate the capacity of soil microbes to store and immobilize C and N at the different warming scenarios. The seven years of chronic soil warming triggered large and proportional soil C and N losses (4.1 ± 0.5% °C −1 of the stocks in unwarmed soils) from the upper 10 cm of soil, with a predominant depletion of the physically accessible organic substrates that were weakly sorbed in soil minerals up to 8.7 °C warming. Soil microbes met the increasing respiratory demands under conditions of low C accessibility at the expenses of a reduction of the standing biomass in warmer soils. This together with the strict microbial C:N stoichiometric demands also constrained their capacity of N retention, and increased the vulnerability of soil to N losses. Our findings suggest a strong control of microbial physiology and C:N stoichiometric needs on the retention of soil N and on the resilience of soil C stocks from high-latitudes to warming, particularly during periods of vegetation dormancy and low C inputs. © 2019 Elsevier Ltd
Martinez-Vilalta J., Anderegg W.R.L., Sapes G., Sala A. (2019) Greater focus on water pools may improve our ability to understand and anticipate drought-induced mortality in plants. New Phytologist. : 0-0.EnllaçDoi: 10.1111/nph.15644
Drought-induced tree mortality has major impacts on ecosystem carbon and water cycles, and is expected to increase in forests across the globe with climate change. A large body of research in the past decade has advanced our understanding of plant water and carbon relations under drought. However, despite intense research, we still lack generalizable, cross-scale indicators of mortality risk. In this Viewpoint, we propose that a more explicit consideration of water pools could improve our ability to monitor and anticipate mortality risk. Specifically, we focus on the relative water content (RWC), a classic metric in plant water relations, as a potential indicator of mortality risk that is physiologically relevant and integrates different aspects related to hydraulics, stomatal responses and carbon economy under drought. Measures of plant water content are likely to have a strong mechanistic link with mortality and to be integrative, threshold-prone and relatively easy to measure and monitor at large spatial scales, and may complement current mortality metrics based on water potential, loss of hydraulic conductivity and nonstructural carbohydrates. We discuss some of the potential advantages and limitations of these metrics to improve our capacity to monitor and predict drought-induced tree mortality. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust
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