Suchergebnisse

13 páginas, 4 figuras. ; 1. Traditionally, techniques of plant manipulation during restoration have focused on the reduction of competition by 'problematic' existing vegetation. However, the increasing recognition of facilitation as a main process regulating the composition of communities has brought a change in the practice of restoration towards a better awareness of the benefits inherent to conserving neighbouring vegetation. 2. Here, I provide the results of a meta-analysis of published studies that have manipulated interactions among plants with the objective of restoring degraded terrestrial systems. I created four different data sets corresponding to the variables most commonly used to measure plant performance (i.e. emergence, survival, growth and density), and asked whether the benefits of facilitation as a restoration tool vary depending on the study duration, the life-form of the neighbour and target species, and the ecosystem type. 3. Neighbour effects varied strongly among performance estimators. Positive effects were frequently found for emergence and survival, whereas neutral or negative interactions predominated for growth and density. 4. No clear support existed for a relationship between study duration and neighbour effect. 5. The life-form of the interacting species, particularly of neighbours, largely influenced the interaction outcome. Herbs had strong negative effects, especially on other herb species, whereas shrubs had large facilitative effects, especially on trees. 6. Semiarid and tropical systems showed in general more positive neighbour effects than wetlands and particularly mesic temperate systems, where negative interactions predominated. However, these results were largely influenced by the over-representation of herb species in wetlands and temperate habitats, survival facilitation being found in all systems when only woody species were considered. 7. Synthesis. Pre-existing vegetation can have large impacts on species establishment in degraded habitats. Inhibition predominates in herbaceous communities typical of early-successional stages, whereas facilitation prevailes in communities dominated by shrubs and trees. Even productive systems (e.g. mesic temperate habitats) appear suitable for the application of facilitation as a restoration tool of woody communities. Whereas restoring herbaceous communities seems largely reliable on removal techniques, augmenting populations of nurse shrubs and trees should be considered a promising strategy for restoring woody late-successional communities. ; This study was supported by a Juan de la Cierva contract to L.G.A, the coordinated Spanish MCINN project INTERBOS (CGL2008-04503-C03-01 ⁄ BOS) and the GESBOME project (RNM 1890) from the Excellence Research Group Programme of the Andalusian Government. ; Peer reviewed

13 pages, 3 figures, 2 tables, 57 references. I am most indebted to Regino Zamora and José María Gómez for their invaluable intellectual and logistical support during this study. I thank the Consejería de Medio Ambiente (Junta de Andalucía) and the Directors of the Sierra Nevada National Park and the Sierra de Baza Natural Park for permission to do fieldwork. Many thanks also to Sergio de Haro, Elena Baraza and José Antonio Hódar for field assistance. David Nesbitt improved the English version. This research is part of REDBOME (www.ugr.es/~redbome/) and GLOBIMED (www.globimed.net) networks on forest ecology. ; 1. Plant recruitment is a multiphase process that takes place in environments that are heterogeneous in space and time. In this work, I analyse how environmental heterogeneity in Mediterranean forests affects dynamics of early recruitment at different scales, using the wind-dispersed tree Acer opalus subsp. granatense as a case study. 2. Seed dispersal and viability, post-dispersal predation, seedling emergence and seedling and sapling survival were evaluated in different habitats (regional scale) and microhabitats (local scale). Simultaneously, a review of the literature on spatial dynamics of plant recruitment in Mediterranean systems was conducted to look for general patterns and investigate their fit to the Acer system. Nineteen woody and herbaceous species were included in the review. 3. At the regional scale, Acer recruitment dynamics strongly converged among sites of the same habitat. This was mainly due to large seedling emergence and survival differences among habitats. Although most of the studies reviewed analyzed only one site per habitat type, they also support strong regional variation (either site- or habitat-specific) in recruitment patterns. 4. At the local scale, Acer recruitment was microhabitat-specific, a result shared by almost all the reviewed species independently of their life form and dispersal syndrome. This was mostly due to spatial differences in seed arrival (higher under conspecifics) and seedling survival (higher under nurse shrubs). 5. Spatial discordance among seed rain and recruitment was found in 60% of the reviewed species at the regional scale, and in 67% at the local scale. Acer results supported this predominant lack of concordance. Discordance among seed rain and recruitment suggests that regeneration is largely limited by safe sites than by seed availability. Because seedling survival was the limiting process with a larger impact on the magnitude and spatial pattern of recruitment, safe sites might be defined as those where seedlings have a higher survival probability. 6. Synthesis : This study indicates that the influence of seed dispersal on the spatial patterns and demography of plant species could be limited in heterogeneous and stressful environments (as are found in the Mediterranean), where recruitment is restricted to a small fraction of the landscape. If we are to preserve the distribution and abundance of Mediterranean species in the face of environmental changes, we need to explicitly consider the strong patch-specificity that characterizes their recruitment process at all scales. ; This study was supported by a grant PFPU-MECD to L.G.A., the Andalusian government grant (PAI) rnm-220 and by the coordinated Spanish MEC projects HETEROMED (REN2002-04041-CO2-01/GLO) and DINAMED (CGL2005-05830-C03-03). ; Peer reviewed

10 páginas.-- 5 figuras.-- 1 tabla.-- 45 referencias.-- Supporting Information Additional Supporting Information may be found in the online versionof this article. Fig. S1. Performance of palm seedlings in each treatment. Fig. S2. Influence of light intensity on VPD. http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12311/suppinfo ; © 2014 British Ecological Society. The degradation of the Andean cloud forest raises strong biological conservation issues and threatens the sustainability of a crucial water resource. The idea that nurse-based restoration can accelerate the recovery of these forests is underexplored, despite its promise as a restoration technique. Recent conceptual models predict that facilitation among plants may be an important mechanism, but there is a lack of strong empirical support. We gathered experimental data to test this prediction and explore the relevance of using nurse-based forest restoration in these environments. A 20-month factorial experimental design in the Andean tropical cloud forest was established. We measured the survival and estimated the biomass production of transplanted seedlings of a keystone canopy forest species, Ceroxylon echinulatum (Arecaceae), in a deforested area in the presence/absence of herbivory, a potential nurse plant (the tussock grass Setaria sphacelata, Poaceae) and artificial shade. The joint effects of deforestation and herbivory led to the death of all seedlings, whereas most seedlings survived in the adjacent forest, which was used as the control. The presence of nurse plants led to significantly higher survival and growth of Ceroxylon seedlings throughout the experiment, regardless of herbivore presence. The nurse effects were explained by a reduction of the relative abiotic stress experienced by the seedlings outside the forest, that is, the consistently decreasing maximum vapour pressure deficit. Furthermore, nurse tussocks delayed and reduced the effects of herbivory by offering physical protection and a refuge for seedlings against detection by herbivores. However, the effects of herbivory and abiotic stress on facilitation were not additive. Synthesis and applications. Facilitation in degraded cloud forest can be intense as soon as the beneficiary plants are driven away from their physiological optimum (relative abiotic stress) and/or are confronted by herbivory. Using pre-established exotic tussock grasses as a nurse-based restoration technique in degraded cloud forest is a low-cost, non-detrimental (to biodiversity) option, especially in the absence of nurse trees and shrubs. The success of this method requires transplanting seedlings at the base of tussocks. Facilitation in degraded cloud forest can be intense as soon as the beneficiary plants are driven away from their physiological optimum (relative abiotic stress) and/or are confronted by herbivory. Using pre-established exotic tussock grasses as a nurse-based restoration technique in degraded cloud forest is a low-cost, non-detrimental (to biodiversity) option, especially in the absence of nurse trees and shrubs. The success of this method requires transplanting seedlings at the base of tussocks. ; We thank the people of the Inti-Llacta Reserve for their kind reception and J. Lincango, S. Cauvy-Fraunie, and C. Gully for their help with data collection. We are also grateful to P. Liancourt and two anonymous reviewers for extensive comments on the manuscript and to the LucidPapers team for English revision. This research was funded by the Ecuadorian government (ECOFONDO grant no. 019-ECO7-Inv1) and the project PALMS FP7-ENV-2007-I (www.fp7-palms.org). ; Peer Reviewed

10 pages, 3 figures, 4 tables, 61 references. We thank the Consejerı´a de Medio Ambiente, Junta de Andalucı´a, for permitting the field work in Sierra Nevada and Sierra de Baza. Sergio de Haro provided invaluable help in the field. Corinna Riginos made constructive comments on the manuscript. David Nesbitt improved the English version. ; Seed dispersal can severely limit the quantity of plant recruits and their spatial distribution. However, our understanding of the role of dispersal in regeneration dynamics is limited by the lack of knowledge of seed deposition patterns in space and time. In this paper, we analyse the spatiotemporal variability of seed dispersal patterns in the Mediterranean maple, Acer opalus subsp. granatense , by monitoring seed rain along two years at a broad spatial scale (2 mountain ranges, 2 populations per range, 4 microhabitats per population). We quantified seed limitation and its components (source and dispersal limitation), and explored dispersal limitation in space by analysing dispersal distances, seed aggregation, and microhabitat seed distribution. Acer opalus subsp. granatense was strongly seed-limited throughout the gradients explored, being always dispersal limitation much higher than source limitation. The distribution of seeds with distance from adult individuals was leptokurtic and right-skewed in all populations, being both kurtosis and skewness higher the year of the highest seed production. Dispersal distances were shorter than expected by random in the four populations, which suggests distancelimited dispersal. Dispersal patterns were highly aggregated and showed a preferential direction around adults. At the microhabitat scale, most seeds accumulated under adult maples. However, there were no more seeds under trees and shrubs other than maple than in open interspaces, implying that established vegetation does not disrupt patterns of seed deposition by physically trapping seeds. When compared with patterns of seedling establishment, limited dispersal ability and inter-annual spatial concordance in seed rain patterns suggest that several potentially safe sites for recruitment have a very low probability of receiving seeds in most maple populations. These findings are especially relevant for rare species such as Acer opalus subsp. granatense , and illustrate how dispersal studies are not only crucial for our understanding of plant population dynamics but also to provide conservation directions. ; Financial support was provided by a PFPU-MECD grant to L.G.A., the Andalusian government grant (PAI) rnm-220, and projects REN2001-4552-E and HETEROMED REN2002-04041-CO2-01/GLO from the Spanish Ministry of Science and Technology (MCYT). ; Peer reviewed

9 pages, 3 figures, 2 tables, 55 references. We thank the Consejería de Medio Ambiente, Junta de Andalucía, for permitting our fieldwork in the Sierra Nevada National Park and Sierra de Baza Natural Park. We are especially grateful to Sergio de Haro, Elena Baraza and Jose Antonio Hódar for their help in the field. Peter Klinkhamer and two anonymous reviewers provided helpful comments on earlier versions of the manuscript. David Nesbitt improved the English version. ; 1 Spatial patterns of seedling establishment have been shown to be largely affected by differences at the microhabitat scale. However, it is far from clear whether such differences are consistent both in space and time, and how they influence the spatial structure of plant populations. 2 We analyse the spatiotemporal variability in microhabitat quality for seedling emergence and survival of the Mediterranean tree Acer opalus ssp. granatense , examining seedling dynamics at the microhabitat scale in two maple populations intermingled in pine forests and two established on stony slopes during three consecutive years with different climatic conditions. 3 Seedling establishment varied markedly between microhabitats. In general, seedlings benefited from the presence of pre-established vegetation, with lower emergence and survival of maple seedlings in open interspaces than under adult maples, non-conspecific trees and shrubs. 4 However, the quality of most microhabitats depended on both habitat type and year. Emergence and survival under adult maples, heterospecific trees and in open interspaces was higher in forest than in stony-slope populations, and increased significantly with summer rainfall. Shrubs, on the contrary, showed relatively high values of seedling emergence and survival at all sites and in both dry and wet years. Consequently, the benefits of living under shrubs were comparatively greater at lower precipitation levels. 5 The different microhabitats found in heterogeneous landscapes such as Mediterranean forests vary, over relatively large spatiotemporal scales, in quality for seedling establishment. Shrubs showed the highest consistency in patterns of both seedling emergence and survival. This finding, together with the predominance of dry years in Mediterranean areas, may explain why Acer opalus ssp. granatense has a stable spatial distribution at a geographical scale with most saplings associated with shrubs. Spatiotemporal patterns of seedling dynamics at the microhabitat scale may cascade through later demographic stages, eventually impacting the spatial structure of plant populations. ; This study was supported by a PFPU-MECD grant to L.G.A., the Andalusian government grant (PAI) rnm-220, and projects REN2001-4552-E and HETEROMED REN2002-04041-CO2-01/GLO from the Spanish Ministry of Science and Technology (MCYT). ; Peer reviewed

Ruiz Benito, P. et al. 14 páginas.-- 3 figuras.-- 2 tablas.-- 50 referencias.-- Additional supporting information may be found in the online version of this article at the publisher's web-site: http://dx.doi.org/10.1111/geb.12515 ; Aim: Biodiversity loss and climate-driven ecosystem modification are leading to substantial changes in forest structure and function. However, the effects of diversity on demographic responses to the environment are poorly understood. We tested the diversity hypothesis (measured through functional diversity) and the mass ratio hypothesis (measured through functional identity) in relation to tree growth, tree mortality and sapling abundance. We sought to determine whether functional diversity underlies demographic responses to environmental variation in European forests. Location: Europe (Spain, Germany, Wallonia, Finland and Sweden). Methods: We used data from five European national forest inventories from boreal to Mediterranean biomes (c. 700,000 trees in 54,000 plots and 143 tree species) and the main forest types across Europe (i.e. from needle-leaved evergreen forests to broad-leaved deciduous forests). For each forest type, we applied maximum likelihood techniques to quantify the relative importance of stand structure, climate and diversity (i.e. functional diversity and functional identity) as determinants of growth, mortality and sapling abundance. We also tested whether demographic responses to environmental conditions (including stand density, evapotranspiration and temperature anomalies) varied with functional diversity. Results: Our results suggest that functional diversity has a positive effect on sapling abundance and growth rates in forests across Europe, while no effect was observed on tree mortality. Functional identity has a strong effect on mortality and sapling abundance, with greater mortality rates in forests dominated by needle-leaved individuals and a greater abundance of saplings in forests dominated by broad-leaved individuals. Furthermore, we observed that functional diversity modified the effects of stand density on demographic responses in Mediterranean forests and the influence of evapotranspiration and temperature anomalies in forests widely distributed across Europe. Main conclusion: Our results suggest that functional diversity may play a key role in forest dynamics through complementarity mechanisms, as well as by modulating demographic responses to environmental variation. ; The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement nos 265171 (FunDivEUROPE) and PCOFUND-GA-2010-267243 (Plant Fellows), The Leverhulme Trust (no. IN-2013-004), the University of Stirling and MINECO (FUNDIVER, no. CGL2015-69186-C2-2-R) ; Peer Reviewed

18 pages, 6 figures, 2 tables, 1 plate, 93 references. This research is part of REDBOME (www.ugr.es/;redbome/) and GLOBIMED (www.globimed.net) networks on forest ecology. ; The ecological impacts of forest plantations are a focus of intense debate, from studies that consider plantations as "biological deserts" to studies showing positive effects on plant diversity and dynamics. This lack of consensus might be influenced by the scarcity of studies that examine how the ecological characteristics of plantations vary along abiotic and biotic gradients. Here we conducted a large-scale assessment of plant regeneration and diversity in plantations of southern Spain. Tree seedling and sapling density, plant species richness, and Shannon's (H0) diversity index were analyzed in 442 pine plantation plots covering a wide gradient of climatic conditions, stand density, and distance to natural forests that act as seed sources. Pronounced variation in regeneration and diversity was found in plantation understories along the gradients explored. Low- to mid-altitude plantations showed a diverse and abundant seedling bank dominated by Quercus ilex, whereas high-altitude plantations showed a virtually monospecific seeding bank of Pinus sylvestris. Regeneration was null in plantations with stand densities exceeding 1500 pines/ha. Moderate plantation densities (500–1000 pines/ha) promoted recruitment in comparison to low or null canopy cover, suggesting the existence of facilitative interactions. Quercus ilex recruitment diminished exponentially with distance to the nearest Q. ilex forest. Richness and H0 index values showed a hump-shaped distribution along the altitudinal and radiation gradients and decreased monotonically along the stand density gradient. From a management perspective, different strategies will be necessary depending on where a plantation lies along the gradients explored. Active management will be required in highdensity plantations with arrested succession and low diversity. Thinning could redirect plantations toward more natural densities where facilitation predominates. Passive management might be recommended for low- to moderate-density plantations with active successional dynamics (e.g., toward oak or pine–oak forests at low to mid altitudes). Enrichment planting will be required to overcome seed limitation, especially in plantations far from natural forests. We conclude that plantations should be perceived as dynamic systems where successional trajectories and diversity levels are determined by abiotic constraints, complex balances of competitive and facilitative interactions, the spatial configuration of native seed sources, and species life-history traits. ; Financial support was provided by a Juan de la Cierva contract (2006-1342) to L. Gómez-Aparicio and the GESBOME project (RNM 1890) from the Excellence Research Group Programme of the Andalusian Government. ; Peer reviewed

11 páginas.- 4 figuras.- 2 tablas.-- 44 referencias.- Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467-019-10453-0 .- Data availability Estimation of species demographic parameters and pairwise competitive coefficients for both climatic treatments are available at Dryad Digital Repository https://doi.org/10.5061/dryad.5d1s952. Average species means for the 19 functional traits included in this experiment are included in Supplementary Table 1. ; Functional traits are expected to modulate plant competitive dynamics. However, how traits and their plasticity in response to contrasting environments connect with the mechanisms determining species coexistence remains poorly understood. Here, we couple field experiments under two contrasting climatic conditions to a plant population model describing competitive dynamics between 10 annual plant species in order to evaluate how 19 functional traits, covering physiological, morphological and reproductive characteristics, are associated with species' niche and fitness differences. We find a rich diversity of univariate and multidimensional associations, which highlight the primary role of traits related to water- and light-use-efficiency for modulating the determinants of competitive outcomes. Importantly, such traits and their plasticity promote species coexistence across climatic conditions by enhancing stabilizing niche differences and by generating competitive trade-offs between species. Our study represents a significant advance showing how leading dimensions of plant function connect to the mechanisms determining the maintenance of biodiversity. ; Funding support to conduct the experiment was provided by the Spanish Ecological Terrestrial Society (AEET, Jóvenes Investigadores grant 2014/2). I.M. P.-R. and L.M. were funded by a "Ramón & Cajal" contract (RYC-2013-13937) and an "Acción 6 UJA" fellowship (EI_RNM4_2017), respectively. O.G. acknowledges postdoctoral financial support provided by the European Union Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (No. 661118-BioFUNC). I.M.P.-R. and L.G.-A. also thank support from the MICINN projects DECAFUN (CGL2015-70123-R) and INTERCAPA (CGL-2014-56739-R). ; Peer reviewed

44 páginas.- 4 figuras.- 2 tablas.- 51 referencias.- Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467-019-10453-0.- Estimation of species demographic parameters and pairwise competitive coefficients for both climatic treatments are available at Dryad Digital Repository https://doi.org/ 10.5061/dryad.5d1s952. Average species means for the 19 functional traits included in this experiment are included in Supplementary Table 1. ; Functional traits are expected to modulate plant competitive dynamics. However, how traits and their plasticity in response to contrasting environments connect with the mechanisms determining species coexistence remains poorly understood. Here, we couple field experiments under two contrasting climatic conditions to a plant population model describing competitive dynamics between 10 annual plant species in order to evaluate how 19 functional traits, covering physiological, morphological and reproductive characteristics, are associated with species¿ niche and fitness differences. We find a rich diversity of univariate and multidimensional associations, which highlight the primary role of traits related to water- and light-use-efficiency for modulating the determinants of competitive outcomes. Importantly, such traits and their plasticity promote species coexistence across climatic conditions by enhancing stabilizing niche differences and by generating competitive trade-offs between species. Our study represents a significant advance showing how leading dimensions of plant function connect to the mechanisms determining the maintenance of biodiversity. ; Funding support to conduct the experiment was provided by the Spanish Ecological Terrestrial Society (AEET, Jóvenes Investigadores grant 2014/2). I.M. P.-R. and L.M. were funded by a "Ramón & Cajal" contract (RYC-2013-13937) and an "Acción 6 UJA" fellowship (EI_RNM4_2017), respectively. O.G. acknowledges postdoctoral financial support provided by the European Union Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement (No. 661118-BioFUNC). I.M.P.-R. and L.G.-A. also thank support from the MICINN projects DECAFUN (CGL2015-70123-R) and INTERCAPA (CGL-2014-56739-R).

12 páginas.-- 3 figuras.-- 1 tabla.-- 58 referencias.-- Special Feature: Intransitive competition and species coexistence.-- Data available from the Dryad Digital Repository: https://doi.org/10.5061/dryad.5d1s9 (Matías, Godoy, Gómez-Aparicio, & Pérez-Ramos, 2018). ; El artículo esta en libre acceso en la revista.-- free access article in this review ; Very little is known about how variation in environmental conditions alters the strength and the structure of competitive networks and what are the consequences of this for species coexistence. We performed a competition experiment with 10 annual plant species to parameterise a population model describing species' dynamics according to their vital rates and pairwise competitive coefficients. Seeds from all species were sown under two different climatic scenarios: (1) right before the first major storm of the growing season and (2) after an imposed fall drought of 2 months simulating an extreme climatic event of intense aridity. Species' demography and competitive responses were used to estimate pairwise stabilising niche differences and average fitness differences. In addition, we used tools from network theory to characterise the structure of multispecies competition from the determinants of species coexistence. Specifically, we evaluated changes in competitive dominance between species pairs, and the prevalence of intransitive competitive relationships for 120 triplets between these two climatic events. The experimental extreme event significantly reduced fitness differences between species pairs. Such an equalising mechanism promotes coexistence. However, niche differences were also reduced in such a way that the number of species pairs whose niche differences overcame their fitness differences was reduced from six to two. Contrary to our expectations, the extreme event did not increase the hierarchy of competitive dominance. Instead, and depending on the technique used, the prevalence of intransitivity remained marginally similar (17% to 22%) or significantly increased from 19.4% to 29.8%. This pattern was likely a consequence of the significant changes in competitive dominance between species pairs (26 changes out of 45; 58%). Although fitness differences were equalised and intransitive competition promoted, our model predicted a lower likelihood of coexistence under the extreme event for both species pairs and triplets, mainly because competitive interactions did not promote enough niche differences to balance the observed fitness asymmetries in our competitive networks. Synthesis. We empirically proved that an extreme climate results in communities with reduced niche and fitness differences in which species are less likely to coexist despite the increasing prevalence of intransitive competition. ; Was funded by a Juan de la Cierva grant (FPDI-2013-15867). O.G. acknowledges postdoctoral financial support provided by the Spanish Ministry for Education and Science (Juan de la Cierva, JCI-2012-12061), and by the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 661118-BioFUNC. Funding support to conduct the experiment was provided by the Spanish Ecological Terrestrial Society (AEET, Jóvenes Investigadores grant 2014/2). L.G.-A. acknowledges support from the MICINN project INTERCAPA (CGL-2014-56739-R) and European FEDER Funds. I.M.P.-R thanks the funding provided by the Ramón & Cajal Research Programme (RYC-2013-13937) and the Spanish MINECO project DECAFUN (CGL2015-70123-R). ; Peer reviewed

12 pages, 4 figures, 4 tables, 73 references. We thank the Consejería de Medio Ambiente, Junta de Andalucía, and the direction of the National Park, for permission to work in Sierra Nevada. We are especially grateful to Empresa de Transformación Agraria S.A. (TRAGSA) for carrying out the experimental plantations. Jose M. Gómez, Sergio de Haro, Elena Baraza and Daniel García kindly helped with the field work. David Nesbitt looked over the English version of the manuscript. ; Question: Positive interactions are predicted to be common in communities developing under high physical stress or high herbivory pressure due to neighbour amelioration of limiting physical and consumer stresses, respectively. However, when both stress sources meet in the same community, the relative importance of the two facilitation mechanisms is poorly understood. We ask: What is the relative importance of abiotic vs. biotic mechanisms of facilitation of tree saplings by shrubs in Mediterranean mountain forests? Location: Sierra Nevada, SE Spain (1800-1850 m a.s.l.) Methods: Saplings of four tree taxa (Acer opalus ssp. granatense, Quercus ilex, Pinus nigra ssp. salzmanii and P. sylvestris var. nevadensis) were planted following a 2 × 2 factorial design: two levels of herbivory (control and ungulate exclusion) and two microhabitats (under shrubs and in open areas). Sapling survival and growth were monitored for five years. Results: Shrubs had positive effects on sapling survival both in control and ungulate excluded plots. This effect was species-specific, with shrubs increasing the survival of Acer opalus and Quercus ilex three and twofold, respectively, but having a minor effect on the Pinus species. Herbivory damage was also species-specific, being much higher for Acer opalus than for any other species. Shrubs did not protect saplings of any species against ungulates. Thus, all Acer saplings (the most damaged species) suffered herbivory outside the exclosures, which largely reduced sapling height. Conclusions: Protection from abiotic stress (summer drought and winter frost) was much more relevant than protection from biotic stress (herbivory). However, we propose that the final balance between the two mechanisms can be expected to vary strongly between sites, depending on the relative magnitude of the different sources of stress and the intrinsic traits (e.g. palatability) of the species interacting. ; This study was supported by a PFPU-MECD grant to L.G.A., the Andalusian government grant (PAI) rnm-220, and projects FEDER 1FD97-0743-CO3-02 and HETEROMED REN2002-04041-CO2-01/GLO from the Spanish Ministry of Science and Technology (MCYT). ; Peer reviewed

16 páginas.-- 5 figuras.-- 1 tablas.-- 56 referencias.-- This article belongs to the Special Issue "Ecology and Management of Invasive Species in Forest Ecosystems". ; There is growing recognition of the importance of soil fauna for modulating nutrient cycling processes such as litter decomposition. However, little is known about the drivers promoting changes in soil fauna abundance on a local scale. We explored this gap of knowledge in a mixed oak forest of Southern Spain, which is under decline due to the invasion of the exotic soil-borne pathogen Phytophthora cinnamomi . Meso-invertebrate abundance found in soil litter was estimated at the suborder level. We then explored their statistical correlations with respect to light availability, tree and litter characteristics, and P. cinnamomi abundance. Oribatida and Entomobryomporpha were the most abundant groups of Acari and Collembola, respectively. According to their trophic level, predator and detritivore abundances were positively correlated while detritivores were, in turn, positively correlated with pathogen abundance and negatively influenced by light availability and tree defoliation. These overall trends differed between groups. Among detritivores, Diplopoda preferred highly decomposed litter while Oribatida and Psocoptera preferred darker environments and Poduromorpha were selected for environments with lower tree defoliation. Our results show the predominant role of light availability in influencing litter fauna abundances at local scales and suggest that the invasive soil-borne pathogen P. cinnamomi is integrated in these complex relationships. ; O.G. acknowledges postdoctoral financial support provided by the European Union Horizon research and innovation program under the Marie Sklodowska-Curie grant agreement No 661118-BioFUNC. O. G. also thanks research support from the Spanish Ministry of Economy and Competitiveness through the IMPLANTIN project (CGL2015-65346-R). L.G.A. acknowledges support from the MICINN project INTERCAPA (CGL-2014-56739-R).

There is growing recognition of the importance of soil fauna for modulating nutrient cycling processes such as litter decomposition. However, little is known about the drivers promoting changes in soil fauna abundance on a local scale. We explored this gap of knowledge in a mixed oak forest of Southern Spain, which is under decline due to the invasion of the exotic soil-borne pathogen Phytophthora cinnamomi. Meso-invertebrate abundance found in soil litter was estimated at the suborder level. We then explored their statistical correlations with respect to light availability, tree and litter characteristics, and P. cinnamomi abundance. Oribatida and Entomobryomporpha were the most abundant groups of Acari and Collembola, respectively. According to their trophic level, predator and detritivore abundances were positively correlated while detritivores were, in turn, positively correlated with pathogen abundance and negatively influenced by light availability and tree defoliation. These overall trends differed between groups. Among detritivores, Diplopoda preferred highly decomposed litter while Oribatida and Psocoptera preferred darker environments and Poduromorpha were selected for environments with lower tree defoliation. Our results show the predominant role of light availability in influencing litter fauna abundances at local scales and suggest that the invasive soil-borne pathogen P. cinnamomi is integrated in these complex relationships. ; Spanish Ministry of Economy and Competitiveness through the IMPLANTIN project (CGL2015-65346-R) ; European Union Horizon research and innovation program under the Marie Sklodowska-Curie grantEuropean Union (EU) [661118-BioFUNC]

10 páginas.- 3 figuras.- 1 tabla.- 47 referencias.- Supplementary information is available for this paper at https://doi.org/10.1038/s41467-020-17960-5 ; Ecologists have long argued that higher functioning in diverse communities arises from the niche differences stabilizing species coexistence and from the fitness differences driving competitive dominance. However, rigorous tests are lacking. We couple field-parameterized models of competition between 10 annual plant species with a biodiversity-functioning experiment under two contrasting environmental conditions, to study how coexistence determinants link to biodiversity effects (selection and complementarity). We find that complementarity effects positively correlate with niche differences and selection effects differences correlate with fitness differences. However, niche differences also contribute to selection effects and fitness differences to complementarity effects. Despite this complexity, communities with an excess of niche differences (where niche differences exceeded those needed for coexistence) produce more biomass and have faster decomposition rates under drought, but do not take up nutrients more rapidly. We provide empirical evidence that the mechanisms determining coexistence correlate with those maximizing ecosystem functioning. ; O.G. acknowledges postdoctoral financial support provided by the European Union Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 661118-BioFUNC. ; Peer reviewed

18 páginas. Three anonymous referees helped us to greatly improve the paper. We are grateful to the Consejería de Medio Ambiente (Andalusian Government) and to the Organismo Autónomo Parques Nacionales for financial support and to the Doñana National Park and Doñana Biological Reserve managers for the use of their facilities and the support to carry out the field work. Héctor Garrido, Eduardo Aguilera and Rubén Rodríguez provided us with valuable information about the wading bird colony. Doñana Monitoring Team members and Eduardo Gutiérrez, Juan S. Cara, Paula Madejón, Pilar Burgos and Vanessa Peiró helped us with the field and/or laboratory analyses. ; Conservation management conflicts frequently arise when an overpopulation of a protected organism has negative effects on other valuable elements in the same ecosystem. We studied the interactions between a colony of protected tree-nesting wading birds and a remnant population of centenarian cork oaks that was part of the formerly dominant forests in the Doñana Biological Reserve (SW Spain). A significant increase in the tree mortality rates has been recorded in areas that are yearly influenced by the bird colony. ; LVG, CA, AM, MTD, LGA and TM were supported by the INTERBOS (CGL2008-4503-C03-01), the DECALDO (091/2009) and the BIOGEOBIRD (P09-RMN-4987) projects. ; Peer reviewed