• Energy Research

The aim of this study was to investigate the impact of restoration management on the composition of a macro-invertebrate community in a formerly, nutrient-poor grassland. Four grassland plots were selected that were last fertilised 7, 11, 24 or 29 years before sampling in 1996. In the same plots it was observed that nutrient impoverishment as a restoration tool resulted in a decrease in primary production and a directional shift in vegetation composition after cessation of fertiliser application. Terrestrial isopods, millipedes, and centipedes were sampled with pitfall traps in the four plots. The directional shift observed in vegetation composition before this study was not accompanied by a directional change in macro-invertebrate composition. Both the field poorest in nutrients and the one richest in nutrients showed the lowest density and species richness, while the species composition was similar across intermediate succession stages. By far the most specimens and species were caught in the field that had not received fertilisers for 24 years. Succession theory could only partly explain the observed results. Canonical correspondence analysis of the data revealed that only a small part of the pattern could be explained by the nutrient status of the grasslands. The C accumulation due to secondary succession of plants was hypothesised to influence the densities and diversity of macro-invertebrate communities in these grasslands.

SummaryRecent observations suggest that repeated fires could drive Mediterranean forests to shrublands, hosting flammable vegetation that regrows quickly after fire. This feedback supposedly favours shrubland persistence and may be strengthened in the future by predicted increased aridity. An assessment was made of how fires and aridity in combination modulated the dynamics of Mediterranean ecosystems and whether the feedback could be strong enough to maintain shrubland as an alternative stable state to forest.A model was developed for vegetation dynamics, including stochastic fires and different plant fire‐responses. Parameters were calibrated using observational data from a period up to 100 yr ago, from 77 sites with and without fires in Southeast Spain and Southern France.The forest state was resilient to the separate impact of fires and increased aridity. However, water stress could convert forests into open shrublands by hampering post‐fire recovery, with a possible tipping point at intermediate aridity.Projected increases in aridity may reduce the resilience of Mediterranean forests against fires and drive post‐fire ecosystem dynamics toward open shrubland. The main effect of increased aridity is the limitation of post‐fire recovery. Including plant fire‐responses is thus fundamental when modelling the fate of Mediterranean‐type vegetation under climate‐change scenarios.

[KEYWORDS: Agriculture Ecosystem services Land use Management optimization Soil Urban Trade-off] On-going human population growth and changing patterns of resource consumption are increasing global demand for ecosystem services, many of which are provided by soils. Some of these ecosystem services are linearly related to the surface area of pervious soil, whereas others show non-linear relationships, making ecosystem service optimization a complex task. As limited land availability creates conflicting demands among various types of land use, a central challenge is how to weigh these conflicting interests and how to achieve the best solutions possible from a perspective of sustainable societal development. These conflicting interests become most apparent in soils that are the most heavily used by humans for specific purposes: urban soils used for green spaces, housing, and other infrastructure and agricultural soils for producing food, fibres and biofuels. We argue that, despite their seemingly divergent uses of land, agricultural and urban soils share common features with regards to interactions between ecosystem services, and that the trade-offs associated with decision-making, while scale- and context-dependent, can be surprisingly similar between the two systems. We propose that the trade-offs within land use types and their soil-related ecosystems services are often disproportional, and quantifying these will enable ecologists and soil scientists to help policy makers optimizing management decisions when confronted with demands for multiple services under limited land availability.

Intensive land use reduces the diversity and abundance of many soil biota, with consequences for the processes that they govern and the ecosystem services that these processes underpin. Relationships between soil biota and ecosystem processes have mostly been found in laboratory experiments and rarely are found in the field. Here, we quantified, across four countries of contrasting climatic and soil conditions in Europe, how differences in soil food web composition resulting from land use systems (intensive wheat rotation, extensive rotation, and permanent grassland) influence the functioning of soils and the ecosystem services that they deliver. Intensive wheat rotation consistently reduced the biomass of all components of the soil food web across all countries. Soil food web properties strongly and consistently predicted processes of C and N cycling across land use systems and geographic locations, and they were a better predictor of these processes than land use. Processes of carbon loss increased with soil food web properties that correlated with soil C content, such as earthworm biomass and fungal/bacterial energy channel ratio, and were greatest in permanent grassland. In contrast, processes of N cycling were explained by soil food web properties independent of land use, such as arbuscular mycorrhizal fungi and bacterial channel biomass. Our quantification of the contribution of soil organisms to processes of C and N cycling across land use systems and geographic locations shows that soil biota need to be included in C and N cycling models and highlights the need to map and conserve soil biodiversity across the world.

Corrigendum to New Phytologist 225 (2020), 1500–1515, doi: 10.1111/nph.16252. Since its publication, the authors of Baudena et al. (2020) have identified an error for the set of parameter values representing flammability in Table 2. In this correction, the authors would also like to report that, when using the flammability values as originally published in Baudena et al. (2020; i.e. a factor 2 larger than those actually used in the simulations), the main results do not change qualitatively (see Supporting Information Figs S1, S2 to this correction). Namely, when increased aridity was simulated as negatively affecting oak post-fire recovery and colonization rate, while positively affecting the community flammability, the authors observed that the forest state was resilient to the separate impact of fires and increased aridity. Yet, water stress could convert forests into open shrublands by hampering post-fire recovery and at the same time either increasing flammability or decreasing the oak forest colonization rate (or both). A tipping point (emerging from bistability of the open shrubland and forest state) was detected at intermediate levels of aridity (Fig. S1). In the ‘short-term’ run, that is a century, the authors observed again that the probability of a mixed successional community becoming an oak forest after 100 yr decreased drastically with increasing aridity (moving from bottom left to top right in Fig. S2, e.g. with flammability equal to 1.5 times the baseline value as published in table 2 in Baudena et al., 2020). The main differences between the two parameter sets were that the effects of aridity were more dramatic in Figs S1 and S2, as their baseline flammability (given in table 2 in Baudena et al., 2020) was twice as high as the baseline flammability that we actually used in figs 3 and 4 in Baudena et al. (2020) (as reported here in Table 2). We apologize to our readers for this mistake. 2 Table List of symbols, names, values, units and their source for the parameters and functions used in Eqn 1. (Table presented.) B, B. retusum; C, Cistus spp.; P, P. halepensis; Q, Quercus spp.; R, R. officinalis; U, U. parviflorus. (It includes the correct values for the flammability parameters (in bold) used in Baudena et al., 2020.) † Sources: aOptimization of the parameters with the successional data (c1–5) and with fire data (c6). bRoy & Sonie (1992), Panaïotis et al. (1997), Pausas (1999b), Caturla (2002), Lloret et al. (2003), Baeza et al. (2006), Raevel et al. (2012), Moya-Delgado (2017). cr1, expert estimation; r6, optimized from fire site data. dExpert estimation. eDaskalakou & Thanos (1996), Martínez-Sánchez et al. (1999), Pausas et al. (2003), Santana et al. (2012, 2014). fCalibration with fire data. Acknowledgements The authors would like to kindly acknowledge Matilde Torrassa for finding the error in the original version of the paper.

Tree mortality appears to be increasing in moist tropical forests 1 , with potentially important implications for global carbon and water cycles 2 . Little is known about the drivers of tree mortality in these diverse forests, partly because long-term data are lacking 3 . The relative importance of climatic factors and species functional traits as drivers of tropical tree mortality are evaluated using a unique dataset in which the survival of over 1,000 rainforest canopy trees from over 200 species has been monitored monthly over five decades in the Central Amazon. We found that drought, as well as heat, storms and extreme rainy years, increase tree mortality for at least two years after the climatic event. Specific functional groups (pioneers, softwoods and evergreens) had especially high mortality during extreme years. These results suggest that predicted climate change will lead to higher tree mortality rates, especially for short-lived species, which may result in faster carbon sequestration but lower carbon storage of tropical forests.