Tropical forests are undergoing a biodiversity crisis including defaunation processes. Structure and function of biotic communities in disturbed ecosystems can be assessed with network analyses of interspecific interactions. In a disturbed tropical forest we studied the network of interactions between fruiting plants and three groups of frugivorous animals, determining the structure, modular roles of species and the robustness of the network under simulated extinction scenarios based on species strength (SS) (relevance), species role (SR) (connectivity) and body size (vulnerability). We recorded 5,347 interactions between 63 frugivore and 60 plant species. The network had a modular structure with four modules: (1) plants with exposed fruits consumed by bats; (2) plants with juicy fruits consumed by larger birds; (3) plants with dry high-lipid-content fruits consumed by migratory birds; and (4) generalist plants consumed by several frugivores (three guilds). Robustness of the network was lower when species with high SS or important connectivity roles (i.e., module hubs) were lost first; when larger animals were lost first the network was more robust than in the other scenarios. Our results suggest that modularity may protect disturbed communities against species loss. We provide bases for developing ecologically-sound measures for the conservation of ecological interactions in anthropogenic landscapes.

Considering that parasitic plant distributions are constrained by host availability, we measure the effects of adding information of host distributions to predict distributions of mistletoes under climate change using ecological niche modeling (ENM). We contrasted ecological niche models of two Psittacanthus mistletoe species, P. schiedeanus, a host-generalist species inhabiting cloud forests, and P. sonorae, a Bursera-specialist restricted to the Sonoran Desert. Mistletoe models that use only climate variables were contrasted with models that also take into account biotic interactions (i.e., host) to evaluate the potential effects that future climatic conditions have on the distributions of these mistletoe-host interactions. Current potential distributions of both mistletoe species were affected by environmental conditions under future climate change scenarios. However, future projected distributions differed between mistletoe species when including host interactions, with improved accuracy models for P. schiedeanus. Our results are consistent with previous studies showing that biotic interactions can be important in structuring species distributions at regional scales.

Based on land-use data collected every five years from 1990 to 2010, we quantified land-use dynamics and resultant effects on the ecosystem services along urban-rural gradients of the Guangzhou-Foshan Metropolitan Area, South China. The urban-rural gradients were set around the urban core cohesion zone with a 10-km-wide buffer zone and the value of each ecosystem service was calculated using a well-established benefit transfer method. The areas of construction land, water body and orchard expanded, while cropland, forestland and unused land contracted. The total value of ecosystem services decreased by US$ 200.33 million (or 4.3%) from 1990 to2010. Along the urbanrural gradients, the average value supplied by cropland, orchard and water body generally demonstrated a ‘first-rise-then-fall’ trend, while forestland and construction land presented an ever-increasing trend. For individual ecosystem services, raw material, gas regulation, climate regulation, soil formation and retention, biodiversity protection, recreation and culture increased steadily along the urban-rural gradients, while food production showed a fluctuating ‘first-rise-then-fall’ trend; water conservation and waste treatment increased fromthe core cohesion zone to the third concentric ring, and then had a sudden surge in the seventh concentric ring in both 2005 and 2010.

The risk of overestimating the number of nocturnal owls during a census is substantial when the territory density is high and no individual signature is available. The tawny owl voice was demonstrated to be individual, but no statistical technique evaluated to date is suitable for a census of this species. To overcome the problem, the combination of two methods is suggested in this study: (1) the Visual Spectrographic Comparison (VSC), a bioacoustics tool which tries to separate owls' voices classifying the spectrograms of their calls based on their visual characteristics, and (2) the extensively used technique of Mapping Method (MM). The technique was applied to a dense population of tawny owls living in an isolated deciduous wood of northern Italy. Fourteen territorial males were individuated in the area, resulting a density of 6.0 pairs/km2. Most of the home ranges seem to overlap substantially, an evidence not in step with the common idea of high territoriality of the species. Since the technique is believed to be exhaustive, a future monitoring of this population could be precise, cheap and very informative. This technique could be easily extended to other elusive species that show individual vocal cues.

Accurate estimates of methane (CH₄) fluxes from restored peatlands are needed to inform emission factor estimations and reporting. Flux measurements are usually taken during the daytime but such measurements may provide biased estimates of overall CH₄ emissions if night-time fluxes differ from daytime fluxes. Diurnal variations in CH₄ fluxes have been reported for a range of peatland types, but not for restored raised bogs which are important carbon stores in some countries. To help fill this knowledge gap, we investigated diurnal variations in CH₄ emissions from a restored raised bog. CH₄ fluxes from a restored raised bog were measured in two 24-hr field campaigns using flux chambers. Carbon dioxide (CO₂) fluxes were also monitored, as were a suite of complementary environmental variables. Night-time CH₄ fluxes were significantly greater than daytime fluxes during both campaigns, by 10.4% and 36.1%, respectively. In Campaign 1 air temperature was the best predictor of CH₄ fluxes, whereas in Campaign 2 net ecosystem exchange (NEE) values were the best predictor. This study shows that diurnal variations in CH₄ fluxes exist in a restored peatland and that current approaches biased to daytime measurements will underestimate CH₄ emissions from restored peatlands to the atmosphere.

Seed dispersal has significantly contributed to horseweed invasion in ecosystems. However, there is a lack of research on long-distance (more than 1 km) and dynamic (hourly) seed movement during an entire seed-shedding season and under different atmospheric conditions. To fill this knowledge gap, the Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) model, accounting for meteorological factors and biological dynamics (hourly-order seed emission), was validated using experimental data. The validated model was run for different atmospheric conditions (wind speed and updraft-vertical turbulence) to estimate the longest distance (LD, from the source with more than 1 seed ha^-1 deposition) and distribution of seed dispersal during one day (8:00 to 18:00). In a weak wind condition (1–4 m s^-1 at 10 m height, standard deviation of vertical wind velocity = 0.5–0.6 m s^-1), LD was about 36.5 km, and 4% of seeds were deposited farther than 5 km. In a strong wind condition (5–7 m s^-1, 0.8–1 m s^-1), LD was 165 km, and 27% were blown farther than 5 km. At the end of the seed-shedding season (44 days), seed dispersal exceeded 186 km; 79% were found within 5 km and 14% were blown farther than 10 km.

Although Italy is among the European countries with the highest number of threatened species, since the turn of the twenty-first century some flagship species, such as Eurasian otter Lutra lutra and wolf Canis lupus, have started to recover. Since 2003 the otter has been newly recorded on the Sila Massif (S. Italy), where it had been reported to have gone extinct in the 1980s. With the aim of outlining the actual range of this population, in 2014–2017 we monitored otter occurrence on eight major rivers. Spraint surveys were carried out on 18–23 sampling stretches every July. Seven stations (Rivers Savuto and Neto-Lese) showed 75–100% positive surveys, while otters were recorded only once at three of the rivers. Monitoring allowed identifying in the catchments of the Rivers Savuto and Neto, which flow on opposite sides of the Sila Massif, otter core population at the southern edge of its Italian range. We assessed the exceptionality of the recent sightings using a surprise index based on the time distribution of pre-disappearance otter records. Analyses suggest that the otter persisted in the area and went unrecorded during the national survey carried out in 1983–1985, stressing the need for further monitoring at national scale.

The relationship between selected environmental variables and plant species composition was studied on two mineralogically different spoil heaps (Hg and Cu) in Central Slovakia with contrasting reclamation approaches. Data on plant species composition were collected by stratified random sampling in defined physiognomic vegetation types. A detrended correspondence analysis showed that most of the variability in species composition was related to the succession gradient from open communities with a low cover of vascular plants to forest vegetation, and to the moisture gradient. Variance partitioning by canonical correspondence analysis revealed that most of the variability in plant composition was related to the content of various heavy metals (27.8% at the Hg-spoil heap and 28.3% at the Cu-spoil heap), but a significant relationship was found only for Mn. Other significant factors comprised soil moisture, pH and P content for the Hg-spoil heap and soil temperature and Ca content for the Cu-spoil heap. Although heavy metal content explained most of the variability in species composition, the relationship was caused by the correlation of heavy metal content with other environmental variables rather than by a direct causal relationship.