74 research outputs found
Contributions of Hedgerows to People: A Global Meta-Analysis
David García de León et al. (2021) 'Contributions of Hedgerows to People: A Global Meta-Analysis', Frontiers in Conservation Science, 2. doi:10.3389/fcosc.2021.789612.Hedgerows are linear landscape features of woody vegetation usually located around agricultural fields. An increasing number of studies have addressed the effects of hedgerows on biodiversity and ecosystem services. This study is aimed to synthesize these effects and compare the levels of biodiversity and ecosystem services in farmland with hedgerows and (1) farmland without hedgerows and (2) nearby natural habitat at the global scale. We hypothesized that farmland with hedgerows (1) enhances biodiversity and ecosystem services as compared to farmland without hedgerows but (2) supports lower levels of biodiversity and ecosystem services than natural habitat. Our systematic literature review retained 835 observations from 170 primary studies, which were analyzed following the standard methodology in meta-analyses. Our results partially support both hypotheses. Farmland with hedgerows exhibited higher levels of biodiversity and provisioning services than farmland without hedgerows (H1). Farmland with hedgerows provided similar levels of biodiversity (edge effects) but lower levels of ecosystem services than natural habitat (H2). The effects of hedgerows on biodiversity and ecosystem services depended on control ecosystem type (grassland/meadow or forest/woodland) but were largely independent of climate type (temperate or tropical) and the focus of spatial scale (field or landscape). In conclusion, conservation and restoration of hedgerows contribute to people in several ways by enhancing biodiversity and multifunctionality in agricultural landscapes.Comunidad de MadridUniversidad de Alcal
Rooting big and deep rapidly: the ecological roots of pine species distribution in southern Europe
Root properties can influence plant drought resistance, and consequently plant species distribution. Root structure strongly varies across biomes partly as a result of phylogeny. However, whether the spatial distribution of phylogenetically close plant species is linked to differences in root properties remains unclear. We examined whether root properties mediate the strong correlation between summer drought intensity and the spatial segregation of pine species native to southern Europe. For this, we compared the seedling root growth and structure of five ecologically distinct pine species grown in 360 L rhizotrons for 19 months under typical hot and dry Mediterranean conditions. We studied the mountain and boreo-alpine pines Pinus sylvestris and Pinus nigra, and the Mediterranean pines Pinus pinaster, Pinus pinea, and Pinus halepensis. Mediterranean pines formed deep roots faster than mountain pines, their shoots and roots grew faster and had higher root growth, especially P. halepensis, at low air temperature. By the end of the study, Mediterranean pines had larger root systems than mountain pines. Neither distribution of root mass with depth nor root-to-shoot mass ratio varied significantly among species. Across species, minimal annual rainfall to which species are exposed in their range related negatively to root growth but positively to specific root length and the time needed for roots to reach a depth of 40 cm. This study highlights the importance of root growth as a driver of pine distribution in southern Europe and suggests that rapidly producing a large, deep root system may be a key attribute for pines to colonize dry Mediterranean locations.info:eu-repo/semantics/acceptedVersio
Multiscale assessment of woody species recruitment in Mediterranean shrublands: facilitation and beyond
Forest recovery in Mediterranean environments is influenced by factors such as aridity, herbivory and facilitation by shrubs, as well as by seed limitation in the case of highly fragmented forests. How these various factors interact can determine the direction of secondary succession, yet these interactions are poorly understood. We assessed the relative importance of several factors in forest species recruitment in Retama sphaerocarpa (L.) Boiss (Retama) shrublands at different spatial scales.Ministerio de Economía y CompetitividadComunidad de Madri
Assessing the relative role of climate on litterfall in Mediterranean cork oak forests
Litterfall plays a key role in the dynamic of forest ecosystems, ultimately determining
forest productivity and carbon and nutrient cycling. Increasing our
understanding on the role of structural and environmental factors controlling
litterfall amount and seasonality is of paramount importance for modelling and
estimating soil carbon sequestration and nutrient cycling under climate change
scenarios. However, the effect of climatic conditions on litterfall has been
scarcely studied, especially in Mediterranean ecosystems. Here, we used nine
years of seasonally collected litterfall data in two contrasting Mediterranean
cork oak forests to evaluate the effect of climatic variables on leaf fall and litterfall.
First, we isolated the litterfall seasonal trend and the between-sites
differences in production by using linear mixed models. Then, we evaluated
the effect of climatic variables and whether this effect was site-specific. We
found a consistent litterfall seasonal pattern, mainly determined by leaf shedding
(70% of litterfall). Leaf fall mainly occurs in spring with a second but
much smaller peak in autumn some years. Mean temperature, precipitation
and mean wind speed strongly influenced litterfall, but this effect was sitespecific.
In the forest site located at higher latitude and altitude, leaf fall increased
linearly with temperature and showed a positive quadratic response to
precipitation. In the water-limited site, leaf fall was reduced as temperature
increased and did not respond to precipitation. These results have implications
for modelling and predicting soil carbon sequestration, nutrient cycling,
and the forest ecosystem productivity. Specifically, carbon and nutrient cycling
models can be improved by incorporating idiosyncratic forest sites responses
to climatic variability.This study was supported by Ministry of Science and Innovation of Spain, the National Agriculture Research Institute (INIA; ref: SUM2006-00026-00-00), and the Diputacio de Girona, Spain. EA was supported by a postdoctoral grant founded by the Universidad Complutense in Madrid. We gratefully acknowledge the logistic support from the Montseny Natural Park, and the valuable help of numerous people during the sampling along the study period. We are also very grateful to Zoe Rohrer for the revision of the English language. The comments and suggestions of two anonymous reviewers contributed to improve previous version of this manuscript
Revegetation through seeding or planting: A worldwide systematic map
Roughly 2 billion ha of land are degraded and in need of ecological restoration worldwide. Active restoration frequently involves revegetation, which leads to the dilemma of whether to conduct direct seeding or to plant nursery-grown seedlings. The choice of revegetation method can regulate plant survival and performance, with economic implications that ultimately feed back to our capacity to conduct restoration. We followed a peer -reviewed protocol to develop a systematic map that collates, describes and catalogues the available studies on how seeding compares to planting in achieving restoration targets. We compiled a database with the charac-teristics of all retrieved studies, which can be searched to identify studies of particular locations and habitats, objectives of restoration, plant material, technical aspects, and outcomes measured. The search was made in eight languages and retrieved 3355 publications, of which 178 were retained. The systematic map identifies research gaps, such as a lack of studies in the global South, in tropical rainforests, and covering a long time period, which represent opportunities to expand field-based research. Additionally, many studies overlooked reporting on important technical aspects such as seed provenance and nursery cultivation methods, and others such as watering or seedling protection were more frequently applied for planting than for seeding, which limits our capacity to learn from past research. Most studies measured outcomes related to the target plants but avoided measuring general restoration outcomes or economic aspects. This represents a relevant gap in research, as the choice of revegetation method is greatly based on economic aspects and the achievement of restoration goals goes beyond the establishment of plants. Finally, we identified a substantial volume of studies conducted in temperate regions and over short periods (0-5 y). This research cluster calls for a future in-depth synthesis, potentially through meta-analysis, to reveal the overall balance between seeding and planting and assess whether the response to this question is mediated by species traits, environmental characteristics, or technical aspects. Besides identifying research clusters and gaps, the systematic map database allows managers to find the most relevant scientific literature on the appropriateness of seeding vs. planting for particular conditions, such as certain species or habitats
Restoring oak forests through direct seeding or planting: Protocol for a continental-scale experiment
The choice of revegetating via direct seeding or planting nursery-grown seedlings influences the potential stresses suffered by seedlings such as herbivory and drought. The outcome of the balance between both revegetation methods may ultimately depend on how species identity and traits such as seed and seedling size interact with environmental conditions. To test this, we will conduct a continental-scale experiment consisting of one mini-experiment replicated by multiple participants across Europe. Each participant will establish a site with seeded and planted individuals of one or more native, locally growing oak (Quercus) species; the selection of this genus aims to favour continental-scale participation and to allow testing the response of a widely distributed genus of broad ecological and economic relevance. At each site, participants will follow the present protocol for seed collection, seeding in the field, nursery cultivation, outplanting, protection against herbivores, site maintenance, and measurement of seedling performance and environmental variables. Each measurement on each species at each site will produce one effect size; the data will be analysed through mixed-effects meta-analysis. With this approach we will assess the main effect of revegetation method, species, plant functional traits, and the potential effect of site-specific effect moderators. Overall, we will provide a continental-scale estimate on the seeding vs. planting dilemma and analyse to what extent the differences in environmental conditions across sites, seed size, functional traits, and the phylogenetic relatedness of species can account for the differences in the effect of revegetation method on seedling performance across study sites and species
Respuesta de dos procedencias de encina a eventos de sequía: una aproximación dendroecológica
Los programas de restauración forestal con encina llevados a cabo en la Península Ibérica han
presentado de manera general una alta mortandad asociada al estrés hídrico. La diversificación
genética de las repoblaciones forestales mediante el uso de ecotipos de ambientes más xéricos
podría ser una estrategia de mitigación del efecto del cambio global sobre dichas plantaciones.
Aunque diversos estudios sugieren que existen diferencias en la adaptación al estrés hídrico entre
ecotipos de esta especie, no abundan estudios que evalúen a largo plazo si estas diferencias
perduran o bien desaparecen fruto de la aclimatación y la alta plasticidad de esta especie. Mediante
el análisis de los anillos de crecimiento de rodajas procedentes de dos ecotipos de encina, de climas
contrastados, plantados en 2008 en una misma área, hemos analizado su crecimiento a lo largo del
tiempo así como la respuesta de ambas regiones de procedencia, en términos de resiliencia, a la
sequía ocurrida durante el 2012. Las plantas de la procedencia más árida mostraron una mayor tasa
de crecimiento y menor mortalidad que la procedencia local. Sin embargo, no encontramos
diferencias entre ecotipos en la respuesta interanual o en la resiliencia a la sequía de 2012. Nuestros
resultados indican que la inclusión de material vegetal de procedencias más áridas en el diseño de
programas de reforestación podría mejorar el desempeño en campo de plantas de encinas
Forest productivity in southwestern Europe controlled by coupled North Atlantic and Atlantic Multidecadal Oscillations
The North Atlantic Oscillation (NAO) depicts annual and decadal oscillatory modes ofvariability responsible for dry spells over the European continent. The NAO therefore holds agreat potential to evaluate the role, as carbon sinks, of water-limited forests under climatechange. However, uncertainties related to inconsistent responses of long-term forestproductivity to NAO have so far hampered firm conclusions on its impacts. We hypothesizethat, in part, such inconsistencies might have their origin in periodical sea surfacetemperature anomalies in the Atlantic Ocean (i.e., Atlantic Multidecadal Oscillation, AMO).Here we show strong empirical evidence in support of this hypothesis using 120 years ofperiodical inventory data from Iberian pine forests. Our results point to AMO+ NAO+ andAMO−NAO− phases as being critical for forest productivity, likely due to decreased winterwater balance and abnormally low winter temperatures, respectively. Our findings could beessential for the evaluation of ecosystem functioning vulnerabilities associated with increasedclimatic anomalies under unprecedented warming conditions in the Mediterranean
Recent increase in tree damage and mortality and their spatial dependence on drought intensity in Mediterranean forests
Resumen de la comunicación oral presentada en XVI Congreso Nacional de la AEET, 16 al 20 de octubre de 2023, Universidad de AlmeríaLand-use and climate change are leading to more frequent and intense tree damage and mortality events. Drought-induced tree mortality is occurring worldwide leading to broad-scale events, but the spatial patterns of tree damage and mortality, their underlying drivers
and their variation over time is largely unknown. We investigated the spatial patterns of tree damage and mortality across Mediterranean forests of the Iberian Peninsula, the underlying effects of competition and climate, and how the spatial patterns and relationships with underlying drivers changed over time. We used the Spanish Forest Inventory to analyse the autocorrelation in tree damage and mortality across forest types, hurdle-gamma models to quantify the effect of competition and climate on tree damage and mortality, and cross-correlograms to assess their spatial dependence and its change over time. We observed a greater magnitude and a stronger autocorrelation in tree damage than mortality, with positive aggregation up to 20 kilometres. There was a spatial dependence between tree damage and mortality with their drivers, with spatial aggregation increasing with water availability, drought intensity and competition. The spatial dependence of tree damage and mortality with the underlying drivers increased over time, particularly for drought intensity. Our results suggest that the combined effect of intense competition and drought could favour more extensive die-off and tree mortality events, providing key information for identifying vulnerable areas and the planning of adaptation measures
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