Dataset of occurrence and incidence of pine processionary moth in Andalusia, south Spain

This dataset provides information about infestation caused by the pine processionary moth (Thaumetopoeapityocampa ([Denis & Schiffermüller], 1775)) in pure or mixed pine woodlands and plantations in Andalusia. It represents a long-term series (1993-2015) containing 81,908 records that describe the occurrence and incidence of this species. Data were collected within a monitoring programme known as COPLAS, developed by the Regional Ministry of Environment and Territorial Planning of the Andalusian Regional Government within the frame of the Plan de Lucha Integrada contra la Procesionaria del Pino (Plan for Integrated Control Against the Pine Processionary Moth). In particular, this dataset includes 4,386 monitoring stands which, together with the campaign year, define the dataset events in Darwin Core Archive. Events are related with occurrence data which show if the species is present or absent. In turn, the event data have a measurement associated: degree of infestation.

Are the metabolomic responses to folivory of closely related plant species linked to macroevolutionary and plant-folivore coevolutionary processes?

The debate whether the coevolution of plants and insects or macroevolutionary processes (phylogeny) is the main driver determining the arsenal of molecular defensive compounds of plants remains unresolved. Attacks by herbivorous insects affect not only the composition of defensive compounds in plants but also the entire metabolome. Metabolomes are the final products of genotypes and are constrained by macroevolutionary processes, so closely related species should have similar metabolomic compositions and may respond in similar ways to attacks by folivores. We analyzed the elemental compositions and metabolomes of needles from three closely related Pinus species with distant coevolutionary histories with the caterpillar of the processionary moth respond similarly to its attack. All pines had different metabolomes and metabolic responses to herbivorous attack. The metabolomic variation among the species and the responses to folivory reflected their macroevolutionary relationships, with P. pinaster having the most divergent metabolome. The concentrations of terpenes were in the attacked trees supporting the hypothesis that herbivores avoid plant individuals with higher concentrations. Our results suggest that macroevolutionary history plays important roles in the metabolomic responses of these pine species to folivory, but plant-insect coevolution probably constrains those responses. Combinations of different evolutionary factors and trade-offs are likely responsible for the different responses of each species to folivory, which is not necessarily exclusively linked to plant-insect coevolution.

Similar local, but different systemic, metabolomic responses of closely related pine subspecies to folivory by caterpillars of the processionary moth

Plants respond locally and systemically to herbivore attack. Most of the research conducted on plant-herbivore relationships at element and molecular levels have focused on the elemental composition or/and certain molecular compounds or specific families of defence metabolites showing that herbivores tend to select plant individuals or species with higher nutrient concentrations and avoid those with higher levels of defence compounds. We performed stoichiometric and metabolomics, both local and systemic, analyses in two subspecies of Pinus sylvestris under attack from caterpillars of the pine processionary moth, an important pest in the Mediterranean Basin. Both pine subspecies responded locally to folivory mainly by increasing relative concentrations of terpenes and some phenolics. Systemic responses differed between pine subspecies, and most of the metabolites presented intermediate concentrations between those of the affected parts and unattacked trees. Our results support the hypothesis that foliar nutrient concentrations are not a key factor for plant selection by adult female processionary moths for oviposition, since folivory was not associated with any of the elements analysed. Phenolic compounds generally did not increase in the attacked trees, questioning the suggestion of induction of phenolics following folivory attack and the anti-feeding properties of phenolics. Herbivory attack produced a general systemic shift in pines, in both primary and secondary metabolism, which was less intense and chemically different from the local responses. Local pine responses were similar between pine subspecies, while systemic responses were more distant.

Disparity in elevational shifts of European trees in response to recent climate warming

Predicting climate-driven changes in plant distribution is crucial for biodiversity conservation and management under recent climate change. Climate warming is expected to induce movement of species upslope and towards higher latitudes. However, the mechanisms and physiological processes behind the altitudinal and latitudinal distribution range of a tree species are complex and depend on each tree species features and vary over ontogenetic stages. We investigated the altitudinal distribution differences between juvenile and adult individuals of seven major European tree species along elevational transects covering a wide latitudinal range from southern Spain (37°N) to northern Sweden (67°N). By comparing juvenile and adult distributions (shifts on the optimum position and the range limits) we assessed the response of species to present climate conditions in relation to previous conditions that prevailed when adults were established. Mean temperature increased by 0.86 °C on average at our sites during the last decade compared with previous 30-year period. Only one of the species studied, Abies alba, matched the expected predictions under the observed warming, with a maximum abundance of juveniles at higher altitudes than adults. Three species, Fagus sylvatica, Picea abies and Pinus sylvestris, showed an opposite pattern while for other three species, such as Quercus ilex, Acer pseudoplatanus and Q. petraea, we were no able to detect changes in distribution. These findings are in contrast with theoretical predictions and show that tree responses to climate change are complex and are obscured not only by other environmental factors but also by internal processes related to ontogeny and demography.

Direct and indirect effects of climate on demography and early growth of Pinus sylvestris at the rear edge: changing roles of biotic and abiotic factors

Global change triggers shifts in forest composition, with warming and aridification being particularly threatening for the populations located at the rear edge of the species distributions. This is the case of Scots pine (Pinus sylvestris) in the Mediterranean Basin where uncertainties in relation to its dynamics under these changing scenarios are still high. We analysed the relative effect of climate on the recruitment patterns of Scots pine and its interactions with local biotic and abiotic variables at different spatial scales. Number of seedlings and saplings was surveyed, and their annual shoot growth measured in 96 plots located across altitudinal gradients in three different regions in the Iberian Peninsula. We found a significant influence of climate on demography and performance of recruits, with a non-linear effect of temperature on the presence of juveniles, and a positive effect of precipitation on their survival. Abundance of juveniles of P. sylvestris that underwent their first summer drought was skewed towards higher altitudes than the altitudinal mean range of the conspecific adults and the optimum elevation for seedlings' emergence. At local level, light availability did not influence juveniles' density, but it enhanced their growth. Biotic interactions were found between juveniles and the herb cover (competition) and between the number of newly emerged seedlings and shrubs (facilitation). Results also highlighted the indirect effect that climate exerts over the local factors, modulating the interactions with the pre-existing vegetation that were more evident at more stressful sites. This multiscale approach improves our understanding of the dynamics of these marginal populations and some management criteria can be inferred to boost their conservation under the current global warming.

Experimental test of postfire management in pine forests: impact of salvage logging versus partial cutting and nonintervention on bird-species assemblages

There is an intense debate about the effects of postfire salvage logging versus nonintervention policies on regeneration of forest communities, but scant information from experimental studies is available. We manipulated a burned forest area on a Mediterranean mountain to experimentally analyze the effect of salvage logging on bird-species abundance, diversity, and assemblage composition. We used a randomized block design with three plots of approximately 25 ha each, established along an elevational gradient in a recently burned area in Sierra Nevada Natural and National Park (southeastern Spain). Three replicates of three treatments differing in postfire burned wood management were established per plot: salvage logging, nonintervention, and an intermediate degree of intervention (felling and lopping most of the trees but leaving all the biomass). Starting 1 year after the fire, we used point sampling to monitor bird abundance in each treatment for 2 consecutive years during the breeding and winter seasons (720 censuses total). Postfire burned-wood management altered species assemblages. Salvage logged areas had species typical of open- and early-successional habitats. Bird species that inhabit forests were still present in the unsalvaged treatments even though trees were burned, but were almost absent in salvage-logged areas. Indeed, the main dispersers of mid- and late-successional shrubs and trees, such as thrushes (Turdus spp.) and the European Jay (Garrulus glandarius) were almost restricted to unsalvaged treatments. Salvage logging might thus hamper the natural regeneration of the forest through its impact on assemblages of bird species. Moreover, salvage logging reduced species abundance by 50% and richness by 40%, approximately. The highest diversity at the landscape level (gamma diversity) resulted from a combination of all treatments. Salvage logging may be positive for bird conservation if combined in a mosaic with other, less-aggressive postfire management, but stand-wide management with harvest operations has undesirable conservation effects.

Herbivory has a greater impact in shade than in sun: response of Quercus pyrenaica seedlings to multifactorial environmental variation

Many biotic and abiotic factors affect seedling establishment in woody plants. In Mediterranean environments, the major factors affecting tree regeneration are light, water, and herbivory. We investigated the response of some morphological and chemical traits of Quercus pyrenaica Willd. seedlings to simulated herbivory (hand removal of 50% of the aerial mass) and two levels of light (sun vs. shade) and water (one vs. two waterings). Water had no appreciable direct effect on morphological or chemical traits. Shaded seedlings grew less but had greater total leaf area. Simulated herbivory decreased the total leaf area, and root and aerial mass. Among the chemical characteristics, shaded seedlings had higher levels of nitrogen and lower levels of condensed tannins. In colorimetric assays of tannins, clipped seedlings had lower absorbances than did unclipped plants, and this effect was more pronounced in the sun than in the shade. Our experiment shows that light availability and herbivory affect the development and defence of Q. pyrenaica seedlings. Although Q. pyrenaica tolerated shade and simulated herbivory, both factors decreased biomass and chemical defence, which could affect the seedlings' future performance.Key words: environmental context, light, mammal herbivory, oak seedlings, Quercus pyrenaica, secondary compounds.

Ungulate damage on Scots pines in Mediterranean environments: effects of association with shrubs

The spatial structure of plant communities as well as the quality and abundance of neighbours can strongly influence the intensity of herbivory suffered by a plant. In this paper, we study the effect of the association with shrubs on the ungulate herbivory suffered by Scots pine (Pinus sylvestris var. nevadensis Christ., Pinaceae) saplings in two isolated, fragmented populations in southeastern Spain. For this, we monitored herbivory on saplings with regard to the microhabitat in which they grew. We distinguished pines growing in open interspaces, on the edge of shrubs and within the canopy of shrubs, and also we distinguished four functional types of shrubs: thorny shrubs, nonthorny shrubs, thorny scrubs, and nonthorny scrubs. Our results show that association with shrubs increases the damage inflicted on Scots pine saplings. In fact, saplings growing in the open patches, far from the shrubs, escaped from herbivory more frequently and incurred less damage than did saplings growing close to shrubs. However, herbivory was also reduced when pine saplings were completely surrounded by shrubs, since then they served as a mechanical barrier. The type of neighbouring shrub did not affect the overall damage suffered by pines, despite the fact that the ungulates damaged the nonthorny scrubs more intensely than the other kinds of shrubs. Consequently, saplings have an advantage when growing within the canopy of shrubs; these constitute key microsites for pine recruitment in these Mediterranean forests.Key words: associational resistance, associational susceptibility, mammalian herbivory, Mediterranean high mountain, neighbouring effects, Pinus sylvestris var. nevadensis.