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\"Over the past 20 years dramatic declines have taken place in UK insect populations. Eventually, such declines must have knock-on effects for other animals, especially high profile groups such as birds and mammals. This authoritative, yet accessible account details the current state of the wildlife in Britain and Ireland and offers an insight into the outlook for the future. Written by a team of the country's leading experts, it appraises the changes that have occurred in a wide range of wildlife species and their habitats and outlines urgent priorities for conservation. It includes chapters on each of the vertebrate and major invertebrate groups, with the insects covered in particular depth. Also considered are the factors that drive environmental change and the contribution at local and government level to national and international wildlife conservation. Essential reading for anyone who is interested in, and concerned about, UK wildlife\"-- Provided by publisher.

Recent advances in sequencing technologies now permit the analyses of plant DNA from fossil samples (ancient plant DNA, plant aDNA), and thus enable the molecular reconstruction of palaeofloras.Hitherto, ancient frozen soils have proved excellent in preservingDNAmolecules, and have thus been the most commonly used source of plant aDNA. However, DNA from soil mainly represents taxa growing a fewmetres fromthe sampling point. Lakes have larger catchment areas and recent studies have suggested that plant aDNAfromlake sediments is a more powerful tool for palaeofloristic reconstruction. Furthermore, lakes can be found globally in nearly all environments, and are therefore not limited to perennially frozen areas. Here,we review the latest approaches and methods for the study of plant aDNA from lake sediments and discuss the progressmade up to the present.Weargue that aDNAanalyses add newand additional perspectives for the study of ancient plant populations and, in time, will provide higher taxonomic resolution and more precise estimation of abundance. Despite this, key questions and challenges remain for such plant aDNA studies. Finally, we provide guidelines on technical issues, including lake selection, and we suggest directions for future research on plant aDNA studies in lake sediments.

Even though a high fraction of angiosperm plants depends on animal pollinators for sexual reproduction, little is known how pollinator service changes across the ranges of plant species and whether it may contribute to range limits. Here, we tested for variation in pollinator service in the North American Arabidopsis lyrata from its southern to northern range edge and evaluated the driving mechanisms. We monitored insect pollinators using time-lapse cameras in 13 populations over two years and spotted 67 pollinating insect taxa, indicating the generalist nature of this plant-pollinator system. Pollinator service was highest at intermediate local flower densities and higher in large compared to small plant populations. Southern populations had generally smaller population sizes, and visitation rate and pollination ratio decreased with latitude. We also found that pollinator visitation was positively correlated with the richness of other flowering plants. This study indicates that plant populations at southern range edges receive only marginal pollinator service if they are small, and the effect of lower pollination is also detectable within populations across the range when the local flower density is low. Results, therefore, suggest the potential for an Allee effect in pollination that manifests itself across spatial scales.

Schedules of survival, growth and reproduction are key life‐history traits. Data on how these traits vary among species and populations are fundamental to our understanding of the ecological conditions that have shaped plant evolution. Because these demographic schedules determine population growth or decline, such data help us understand how different biomes shape plant ecology, how plant populations and communities respond to global change and how to develop successful management tools for endangered or invasive species. Matrix population models summarize the life cycle components of survival, growth and reproduction, while explicitly acknowledging heterogeneity among classes of individuals in the population. Matrix models have comparable structures, and their emergent measures of population dynamics, such as population growth rate or mean life expectancy, have direct biological interpretations, facilitating comparisons among populations and species. Thousands of plant matrix population models have been parameterized from empirical data, but they are largely dispersed through peer‐reviewed and grey literature, and thus remain inaccessible for synthetic analysis. Here, we introduce the compadre Plant Matrix Database version 3.0, an open‐source online repository containing 468 studies from 598 species world‐wide (672 species hits, when accounting for species studied in more than one source), with a total of 5621 matrices. compadre also contains relevant ancillary information (e.g. ecoregion, growth form, taxonomy, phylogeny) that facilitates interpretation of the numerous demographic metrics that can be derived from the matrices. Synthesis. Large collections of data allow broad questions to be addressed at the global scale, for example, in genetics (genbank), functional plant ecology (try, bien, d3) and grassland community ecology (nutnet). Here, we present compadre, a similarly data‐rich and ecologically relevant resource for plant demography. Open access to this information, its frequent updates and its integration with other online resources will allow researchers to address timely and important ecological and evolutionary questions.

The two-spotted spider mite (TSSM), Tetranychus urticae, is among the most destructive piercing-sucking herbivores, infesting more than 1100 plant species, including numerous greenhouse and open-field crops of significant economic importance. Its prolific fecundity and short life cycle contribute to the development of resistance to pesticides. However, effective resistance loci in plants are still unknown. To advance research on plant-mite interactions and identify genes contributing to plant immunity against TSSM, efficient methods are required to screen large, genetically diverse populations. In this study, we propose an analytical pipeline utilizing high-resolution imaging of infested leaves and an artificial intelligence-based computer program, MITESPOTTER, for the precise analysis of plant susceptibility. Our system accurately identifies and quantifies eggs, feces and damaged areas on leaves without expert intervention. Evaluation of 14 TSSM-infested Arabidopsis thaliana ecotypes originating from diverse global locations revealed significant variations in symptom quantity and distribution across leaf surfaces. This analytical pipeline can be adapted to various pest and host species, facilitating diverse experiments with large specimen numbers, including screening mutagenized plant populations or phenotyping polymorphic plant populations for genetic association studies. We anticipate that such methods will expedite the identification of loci crucial for breeding TSSM-resistant plants.

1. There is increasing evidence that species diversity enhances the temporal stability (TS) of community productivity in different ecosystems, although its effect at the population and tree levels seems to be negative or neutral. Asynchrony in species responses to environmental conditions was found to be one of the main drivers of this stabilizing process. However, the effect of species mixing on the stability of productivity, and the relative importance of the associated mechanisms, remain poorly understood in forest communities. 2. We investigated the way mixing species influenced the TS of productivity in Pinus sylvestris L. and Fagus sylvatica L. forests, and attempted to determine the main drivers among overyielding, asynchrony between species annual growth responses to environmental conditions, and temporal shifts in species interactions. We used a network of 93 experimental plots distributed across Europe to compare the TS of basal area growth over a 15-year period (1999-2013) in mixed and monospecific forest stands at different organizational levels, namely the community, population and individual tree levels. 3. Mixed stands showed a higher TS of basal area growth than monospecific stands at the community level, but not at the population or individual tree levels. The TS at the community level was related to asynchrony between species growth in mixtures, but not to overyielding nor to asynchrony between species growth in monospecific stands. Temporal shifts in species interactions were also related to asynchrony and to the mixing effect on the TS. 4. Synthesis. Our findings confirm that species mixing can stabilize productivity at the community level, whereas there is a neutral or negative effect on stability at the population and individual tree levels. The contrasting findings regarding the relationships between the temporal stability and asynchrony in species growth in mixed and monospecific stands suggest that the main driver in the stabilizing process may be the temporal niche complementarity between species rather than differences in species' intrinsic responses to environmental conditions.

A fundamental goal of ecology is to predict how strongly one species affects the abundance of another. However, our ability to do so is hindered by the fact that interaction outcomes are notoriously variable in space and time (i.e. context‐dependent) and we lack a predictive understanding of the factors that drive this context‐dependence. Determining whether abiotic factors, in particular, predictably shift the outcome of species interactions is of critical importance for many contemporary problems, from forecasting climate change impacts to predicting the efficacy of weed biocontrol. In this essay, we highlight the context‐dependent nature of interactions between plants and their pollinators and herbivores. We advocate for approaches that will identify whether particular abiotic factors predictably shift how strongly these interactions influence plant abundance and/or population growth. We review long‐standing theory that describes how abiotic context should influence the selective impacts of pollinators and herbivores on plants and articulate why this theory requires modification to predict population‐level effects. Finally, we propose several empirical approaches to address gaps in existing knowledge: (i) experiments across broad abiotic gradients to determine whether the outcome of interactions between pollinators or herbivores and plants varies consistently with changing abiotic conditions; (ii) experiments that manipulate the underlying environmental gradient to elucidate whether the abiotic factor that correlates with interaction outcome is causal; and (iii) seed addition studies to explore how strongly seedling recruitment correlates with seed input (as affected by pollen limitation or herbivory) and to quantify how the strength of the seed‐to‐seedling linkage is influenced by the underlying abiotic gradient. Synthesis. Our understanding of the underlying drivers of context‐dependent plant–animal interactions is currently not well developed. Progress in this area is essential to better predict when and where species interactions will alter the responses of plant populations to environmental changes as well as to develop more robust theory. Experiments aimed at explicitly exploring the role of abiotic factors in mediating the population‐level impact of pollen limitation and herbivory could determine the extent to which variation in the abiotic environment predictably shifts the outcome of these interactions.

1. Competition among conspecifics of the same cohort has been traditionally thought to be a main process driving population dynamics. In this classical view, however, the role of facilitation in stressful conditions has rarely been considered. Here, using a transplant experiment across a forest-prairie gradient, we test whether the stress gradient hypothesis (SGH) extends to individuals thought to be strongly competing. 2. We transplanted 2-year-old seedlings oí Nothofagus pumilio at two different densities (clusters of 10 and isolated) and at different distances from the forest edge (from 30 m inside the forest up to 50 m outside the forest in the prairie). We further stem-mapped all seedlings belonging to the clusters and computed a competition index (CI). After 3 years of growing, survival and increment growth in diameter and height were measured and analysed using mixed-effects models. We conducted a nearest-neighbour analysis using seedlings' CI and growth and computed model fit using the area under the curve (AUC) method. 3. Seedlings planted in dense clusters had significantly higher survival than solitary seedlings at the stressful end of the gradient. This trend was reversed at the opposite end of the gradient, supporting the SGH at the intraspecific level. Pursuing this at the level of the individual, we found that higher CIs (more neighbours) in seedlings predicted higher probabilities of their survival (facilitation) in stressful conditions. 4. Seedlings diameter and height increment growth were not affected by planting density and only diameter varied along the stress gradient; seedlings had higher diameter increments in growth outside the forest. Finally, when compared with conceptual models, our results mostly support predictions of a higher facilitation at intermediate position along the gradient. 5. Synthesis. We showed that facilitation overrides competition among tree seedlings even at locations under moderate stress; the facilitation process occurs in resource-mediated interactions (niche overlapping). These results represent an important shift in our way to understand the densitydependent mortality process, and calls for a model reformulation including positive interactions even when competition is expected to be strongest (conspecifics of the same cohort).

Frost effects on savanna plant communities have been considered as analogous to those from fire, both changing community structure and filtering species composition. However, while frost impacts have been well-studied for the woody component of savannas, it is still poorly explored for the ground-layer community. Here, we investigated effects of frost in the Cerrado along a gradient of tree cover, focusing on ground-layer plant species, near the southern limit of the Cerrado in Brazil. We aimed to elucidate if the pattern already described for the tree layer also extends to the ground layer in terms of mimicking the effects of fire on vegetation structure and composition. We assessed how damage severity differs across species and across the tree-cover gradient, and we examined the recovery process after frost in terms of richness and community structure along the canopy cover gradient. Frost caused immediate and widespread dieback of the perennial ground-layer, with greatest impact on community structure where tree cover was lowest. However, frost did not reduce the number of species, indicating community resilience to this natural disturbance. Although frost mimicked the effects of fire in some ways, in other ways it differed substantially from fire. Unlike fire, frost increases litter cover and decreases the proportion of bare soil, likely hindering crucial processes for recovery of plant populations, such as seed dispersal, seed germination and plant resprouting. This finding calls attention to the risk of misguided conclusions when the ground layer is neglected in ecological studies of tropical savannas and grasslands.

1. Facilitation (positive interaction) has received increasing attention in plant ecology over the last decade. Just as for competition, distinguishing different modes of facilitation (mutualistic, commensal or even antagonistic) may be crucial. 2. We therefore introduce the new concept of symmetric versus asymmetric facilitation and present a generic individual-based zone-of-influence model. The model simultaneously implements different modes of both facilitation and competition among individual plants via their overlapping zone of influence. Because we consider facilitation modes as a continuum related to environmental context, we integrated this concept with the stress-gradient hypothesis (SGH) by exploring differences in spatial pattern formation in self-thinning plants along a stress gradient in our model. 3. The interplay among modes of interaction creates distinctly varied spatial patterns along stress gradients. When competition was symmetric, symmetric facilitation (mutualism) consistently led to plant aggregation along stress gradients. However, asymmetric facilitation (commensalism) produces plant aggregation only under more benign conditions but tends to intensify local competition and spatial segregation when conditions are harsh. When competition was completely asymmetric, different modes of facilitation contributed little to spatial aggregation. 4. Symmetric facilitation significantly increased survival at the severe end of the stress gradient, which supports the claim of the SGH that facilitation should have generally positive net effects on plants under high stress levels. Asymmetric facilitation, however, was found to increase survival only under intermediate stress conditions, which contradicts the current predictions of the SGH. 5. Synthesis. Our modelling study demonstrates that the interplay between modes of facilitation and competition affects different aspects of plant populations and communities, implying context-dependent outcomes and consequences. The explicit consideration of the modes and mechanisms of interactions (both facilitation and competition) and the nature of stress factors will help to extend the framework of the SGH and foster research on facilitation in plant ecology.