509 research outputs found
Acer-Fraxinus dominated woods of the Italian Peninsula: a floristic and phytogeographical analysis.
Forest communities dominated by noble broad-leaved trees (maple, lime and ash) in Europe are of elevated scientific and conÂservation interest for the European Union. In this paper, we first present a synthesis of the maple and ash forests in peninsular Italy. By classifying these forests, we distinguish seven main groups for the territory, which only broadly match the syntaxa proposed in the literature. The variability of the Apennine data is then analysed floristically and phytogeographically (using chorological components) in a central-southern European context, using numerical classification, INSPAN, and direct ordination of several synoptic tables. These analyses allow us to identify six different groups of European Acer-Fraxinus communities. Canonical VariÂates Analysis (CVA) of the geographical components confirms the existence of distinct phytogeographical groups. In particular, we highlight the clear distinction between central European (including the Alps) and southern European coenoses. Among the latter there was a clear floristic and chorological distinction between Balkan and Apennine groups. These results reflect the biogeographical subdivisions of Europe, but do not support the syntaxonomical schemes proposed by other authors, which are based only on floristic-ecological information or (recently) use a smaller data set of Italian relevĂ©s. This study also shows that syntaxonomical schemes above the association level should pay more attention to phytogeographical aspects rather than focus on floristic-ecological information alone, in order to propose models that are of value on a geographical scale
Fine-scale fern ecological responses inform on riparian forest habitat conservation status
The recognition of the ecological quality of ecosystems and habitats therein is increasingly important in the Anthropocene. However, there are still scarcely explored ways of how and what to assess to obtain a sound ecological status of habitats. Ferns are an understudied plant group, especially given their usefulness as ecological indicators. Disentangling biotic and abiotic factors that drive fine-scale fern distribution could provide insight into the quality of their habitats. We investigated the environmental factors affecting the distribution of different largely distributed fern species in Europe. We studied their presence and abundance at different life stages in a forest habitat of European priority conservation concern. Our aim was to understand whether fern species can be used as an ecological indicator group in riparian alderwood habitat. We sampled 120 plots of 50 m(2) in randomly selected transects along streams of a riparian forest habitat characterized by the presence of many fern species in the understory, controlling for the effects of geology and elevation. Within each plot, fern species were recorded, including vegetative and generative stages of each ramet (rosette of fronds). We modelled fern occurrence and abundance for the different fern life stages, and diversity indices of the fern community in relation to environmental predictors. We found that population- and community-level responses of ferns mainly depended on soil granulometry and, to a lesser extent, moss cover and stream orientation. We also found that the generative life stage compared to the vegetative adult stage benefits from different ecological characteristics for certain fern species. Alterations of the natural hydrology might lead to a general deterioration in habitat quality for ferns. We suggest that some fern species acting as early-warning species, and potentially their life stages, can be used as an ecological quality indicator for riparian forest habitats. This study deepened the understanding of the fine-scale ecology of an array of European ferns in riparian forests and provides valuable information to assist in the conservation of fern species and their populations
Seasonality fluctuations recorded in fossil bivalves during the early Pleistocene: implications for climate change
Understanding the transformations of the climate system may help to predict and reduce the effects of global climate change. The geological record provides a unique archive that documents the long-term fluctuations of environmental variables, such as seasonal change. Here, we investigate how seasonal variation in seawater temperatures varied in the Mediterranean Sea during the early Pleistocene, approaching the Early-Middle Pleistocene Transition (EMPT) and the beginning of precession-driven Quaternary-style glacialâinterglacial cycles. We performed whole-shell and sclerochemical stable isotope analyses (ÎŽ18O, ÎŽ13C) on bivalves, collected from the lower Pleistocene Arda River marine succession (northern Italy), after checking shell preservation. Our results indicate that seawater temperature seasonality was the main variable of climate change in the Mediterranean area during the early Pleistocene, with the Northern Hemisphere Glaciation (NHG) exerting a control on the Mediterranean climate. We show that strong seasonality (14.4â16.0 °C range) and low winter paleotemperatures (0.8â1.6 °C) were likely the triggers leading to the establishment of widespread populations of so called ânorthern guestsâ (i.e., cold water taxa) in the Mediterranean Sea around 1.80 Ma. The shells postdating the arrival of the ânorthern guestsâ record a return to lower seasonal variations and higher seawater paleotemperatures, with seasonality increasing again approaching the EMPT; the latter, however, is not associated with a corresponding cooling of mean seawater paleotemperatures, showing that the observed seasonality variation represents a clear signal of progressive climate change in the Mediterranean Sea
Robotic Monitoring of Habitats: the Natural Intelligence Approach
In this paper, we first discuss the challenges related to habitat monitoring and review possible robotic solutions. Then, we propose a framework to perform terrestrial habitat monitoring exploiting the mobility of legged robotic systems. The idea is to provide the robot with the Natural Intelligence introduced as the combination of the environment in which it moves, the intelligence embedded in the design of its body, and the algorithms composing its mind. This approach aims to solve the challenges of deploying robots in real natural environments, such as irregular and rough terrains, long-lasting operations, and unexpected collisions, with the final objective of assisting humans in assessing the habitat conservation status. Finally, we present examples of robotic monitoring of habitats in four different environments: forests, grasslands, dunes, and screes
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