Evapotranspiration is a major component of the water cycle, yet only daytime transpiration is currently considered in Earth system and agricultural sciences. This contrasts with physiological studies where 25% or more of water losses have been reported to occur occurring overnight at leaf and plant scales. This gap probably arose from limitations in techniques to measure nocturnal water fluxes at ecosystem scales, a gap we bridge here by using lysimeters under controlled environmental conditions. The magnitude of the nocturnal water losses (12–23% of daytime water losses) in row-crop monocultures of bean (annual herb) and cotton (woody shrub) would be globally an order of magnitude higher than documented responses of global evapotranspiration to climate change (51–98 vs. 7–8 mm yr−1). Contrary to daytime responses and to conventional wisdom, nocturnal transpiration was not affected by previous radiation loads or carbon uptake, and showed a temporal pattern independent of vapour pressure deficit or temperature, because of endogenous controls on stomatal conductance via circadian regulation. Our results have important implications from large-scale ecosystem modelling to crop production: homeostatic water losses justify simple empirical predictive functions, and circadian controls show a fine-tune control that minimizes water loss while potentially increasing posterior carbon uptake.

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Soil microclimate is a potentially important regulator of the composition of plant-associated fungal communities in climates with significant drought periods. Here, we investigated the spatio-temporal dynamics of soil fungal communities in a Mediterranean Pinus pinaster forest in relation to soil moisture and temperature. Fungal communities in 336 soil samples collected monthly over 1 year from 28 long-term experimental plots were assessed by PacBio sequencing of ITS2 amplicons. Total fungal biomass was estimated by analysing ergosterol. Community changes were analysed in the context of functional traits. Soil fungal biomass was lowest during summer and late winter and highest during autumn, concurrent with a greater relative abundance of mycorrhizal species. Intra-annual spatio-temporal changes in community composition correlated significantly with soil moisture and temperature. Mycorrhizal fungi were less affected by summer drought than free-living fungi. In particular, mycorrhizal species of the short-distance exploration type increased in relative abundance under dry conditions, whereas species of the long-distance exploration type were more abundant under wetter conditions. Our observations demonstrate a potential for compositional and functional shifts in fungal communities in response to changing climatic conditions. Free-living fungi and mycorrhizal species with extensive mycelia may be negatively affected by increasing drought periods in Mediterranean forest ecosystems.

Summary1. The importance of peatlands is being increasingly recognized internationally for both the conservation of biodiversity and the provision of ecosystem services; strategies are being developed world-wide to help maintain their integrity. Prescribed burning has been highlighted as a threat with considerable debate over its use as it is perceived to produce a Calluna vulgaris monoculture and a decline in preferred peat-forming species. 2. We investigated the impact of prescribed burning on vegetation composition and diversity in a long-term experiment at Moor House NNR in northern England. The study comprised a comparison between no-burn reference plots last burned in ca. 1924 and an experiment where all plots were burned in 1954/5. Within the experiment, the effects of very light sheep grazing vs. no grazing and three burning rotations (no-burn since 1954/5, repeat-burning at 10-and 20-year intervals) were tested. 3. Calluna vulgaris and Hypnum jutlandicum cover and bryophyte species richness increased in the least-disturbed, no-burn reference plots, but bryophyte cover did not. Lichen diversity declined. 4. Within the formal experiment, low-intensity sheep grazing had little impact but there were substantive changes produced by the different burning rotations. There was divergence between the burning rotation treatments with the least-disturbed, no-burn treatment changing towards a C. vulgaris-H. jutlandicum community, whereas the most-disturbed 10-year rotation had a much greater abundance of both Eriophorum and Sphagnum spp. 5. Synthesis and applications. Our findings suggest that blanket-bog vegetation on peat responds to prescribed burning in a complex manner. Where burn return interval is long (>20 years), C. vulgaris becomes dominant and there was no evidence that preferred peatforming species (Eriophorum/Sphagnum) increased. Where burn return interval is short (10 years), E. vaginatum/Sphagnum abundance increased. We found no evidence to suggest that prescribed burning was deleterious to the abundance of peat-forming species; indeed, it was found to favour them. These results inform conservation management policy for blanket bogs in the UK and more generally for future wildfire-mitigation strategies on dwarf-shrubdominated peatlands elsewhere. Some lessons for the management of long-term experimental studies are also discussed.

This document is the authors' final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. There may be differences between this and the publisher's version. You are advised to consult the publisher's version if you wish to cite from this article.

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Question: How is vegetation succession on coal mine wastes under a Mediterranean climate affected by the restoration method used (topsoil addition or not)? How are plant successional processes influenced by local landscape and soil factors? Location: Reclaimed coal mines in the north of Palencia province, northern Spain (42°47′‐42°50′ N, 4°32′‐4°53′ W). Methods: In Jun–Jul 2008, vascular plant species cover was monitored in 31 coal mines. The mines, which had been restored using two restoration methods (topsoil addition or not), comprised a chronosequence of different ages from 1 to 40 yr since restoration started. Soil and environmental factors at each mine were monitored and related to species cover using a combination of ordination methods and Huisman–Olff–Fresco modeling. Results: Plant succession was affected by restoration method . Where topsoil was added, succession was influenced by age since restoration and soil pH. Where no topsoil was added, soil factors seem to arrest succession. Vegetation composition on topsoiled sites showed a gradient with age, from the youngest, with early colonizing species, to oldest, with an increase in woody species. Vegetation on non‐topsoiled sites comprised mainly early‐successional species. Response to age and pH of 37 species found on topsoiled mines is described. Conclusions: Restoration of coal mines under this Mediterranean climate can be relatively fast if topsoil is added, with a native shrub community developing after 15 yr. However, if topsoil is not used, it takes more than 40 yr. For topsoiled mines, the species found in the different successional stages were identified, and their tolerance to soil pH was derived. This information will assist future restoration projects in the area.

Summary1. The search for appropriate management strategies to control invasive plants is an important theme in environmental management. However, the recovery of the resident community species complement does not necessarily respond predictably to restoration efforts. Increasing restoration success requires an understanding of the resistance and resilience of the invaded community and the response of the newly developing community to management. Here, we used Pteridium-invaded heath and grass communities as a test system and investigated the effects of recommended Pteridium aquilinum control treatments on vegetation composition and diversity. 2. We evaluated seven field experiments in four regions of Great Britain designed to test five Pteridium control treatments, including 'one-off' (applied only at the start) and 'repeated' (applied regularly) treatments, against an untreated experimental control. The sites had context-dependent restoration targets, either a Calluna heathland or acid grassland. Species cover and diversity responses (higher plants, mosses plus lichens) to these treatments were monitored annually for 10 years. 3. Pteridium control treatments induced significant change in species composition compared to experimental controls in both vegetation types. On Calluna target sites, 'repeated' treatments overcame the resistance of the invaded community producing a gradual divergence in species composition and species diversity. In contrast, the 'one-off' treatments were ineffective. 4. At the acid grassland target sites, all treatments overcame the resistance of the Pteridiumdominated state producing changes in species composition in comparison with experimental controls. 5. Synthesis and applications. There are two important results for land managers: (i) where Calluna heathland is the target, 'repeated' treatments (cutting once or twice per year) were effective in overcoming the resistance of invaded community and moving species composition towards the target state, effectively creating an alternative state; (ii) where acid grassland is the target both 'one-off' and 'repeated' treatments overcame the invaded community resistance ('one-off' also overcame resilience) producing changes in species composition in the desired direction. The effectiveness of 'one-off' treatments was site dependent and produced alternative stable states within 10 years. In contrast, 'repeated' treatments were site independent but took longer to work and were more expensive.