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Spatio-ecological heterogeneity is strongly linked to many ecological processes and functions such as plant species diversity patterns and change, metapopulation dynamics, and gene flow. Remote sensing is particularly useful for measuring spatial heterogeneity of ecosystems over wide regions with repeated measurements in space and time. Besides, developing free and open source algorithms for ecological modelling from space is vital to allow to prove workflows of analysis reproducible. From this point of view, NASA developed programs like the Surface Biology and Geology (SBG) to support the development of algorithms for exploiting spaceborne remotely sensed data to provide a relatively fast but accurate estimate of ecological properties in vast areas over time. Most of the indices to measure heterogeneity from space are point descriptors : they catch only part of the whole heterogeneity spectrum. Under the SBG umbrella, in this paper we provide a new R function part of therasterdivR package which allows to calculate spatio-ecological heterogeneity and its variation over time by considering all its possible facets. The new function was tested on two different case studies, on multi- and hyperspectral images, proving to be an effective tool to measure heterogeneity and detect its changes over time.

Puccinellia fasciculata is a littoral miohalophyte with a Mediterranean-Atlantic distribution, uncommonly found in inland sites. The main Italian inland population is located in the Salse di Nirano Reserve, an area internationally renowned for the phenomenon of mud volcanoes. In this study, molecular markers are used to characterize this population and its possible relationships with the nearest littoral conspecific population. A survey of ISSR markers revealed low levels of genetic diversity (He = 0.081 in the inland population, 0.105 in the littoral one) and a weak genetic differentiation (Gst = 0.24 within the inland population, 0.28 among this and the littoral one). A sequence analysis of three non-coding regions of chloroplast DNA found no genetic differentiation both within the inland population and between the two populations, and revealed a common origin for the two dating back to the middle Holocene. The apparent incongruence between the results from the two approaches may be explained by differences between ISSR and non-coding cpDNA markers in capturing signatures related to gene flow; their integrated information implies a mixed reproductive strategy and a common evolutionary history for the two examined populations. Effective conservation strategies are recommended for the inland population of P. fasciculata and its habitat.

Context: Preserving hydrophyte and wetland plant diversity is among the most critical environmental issues worldwide. The progressive decline and disappearance of these species led to dramatic consequences on functions and services provided by inland aquatic ecosystems. This is especially relevant for lowlands that are usually disturbance-dominated landscapes, mainly by mechanization in agriculture and land use changes. Objectives: In these contexts, it is fundamental to understand the key factors affecting the aquatic and wetland plant richness, focusing on relict aquatic habitats, and overcoming a purely trophic-oriented approach. Methods: To do this, the aquatic and wetland flora of 88 aquatic sites, encompassed in an oversimplified watershed, was explored in terms of the total number of aquatic and wetland plant species, hydrophytes, alien species, and policy species, as well as 18 explanatory variables, including eco-morphological, hydrological, direct human impact, and landscape mosaic drivers. Results: The results emphasize the key role of site area and hydrological connectivity compared to land-use intensity in explaining hydrophyte and wetland plant richness in overexploited landscapes; conversely, site origin was crucial only for alien species, being more abundant in artificial sites. Conclusions: This paper offers a new comprehension of the leading contribution of local drivers in explaining macrophyte patterns, suggesting a relevant influence of habitat dynamics in regulating species establishment and developing. The future challenge will be to actively include artificial and/or altered aquatic ecosystems in hydrophyte and wetland plants conservation programs, not forgetting the risks associated with an increasingly spread of alien species. Graphic Abstract: [Figure not available: see fulltext.].

Urban sprawl is defined as an inefficient urban development often linked to sparse building density over rural areas. Routinely available remote sensing data on land cover are useful to study such phenomena, focus is on large raster maps of Urban Morphological Zones (UMZ) produced by the CORINE Land Cover programme of the European Environmental Agency. We present statistical indices to investigate changes in urban size and morphology between sub-regions within a predefined study area and show their implementation with raster data representing UMZ. Urban size is measured by urban land proportion, while morphology is quantified by Moran’s I spatial correlation index. These two area-proportionately additive measures allow comparisons between urban size and morphology in sub-regions of different size to be performed. An urban sprawl scatterplot displaying Moran’s I vs. urban land proportion is proposed as a tool to compare the urban sprawl level in pre-defined sub-regions with respect to a global average level. This scatterplot allows urban sprawled regions within a map to be identified and also an assessment of whether sprawl is due to augmented urban size or decreased urban compactness. An example of the methods is given for Bologna province, Northern Italy, where the interest is in detecting types of urban sprawl at several spatial scales, i.e. municipalities and unions of municipalities, within the whole province.

Chestnut stands (orchards and coppices) are among the most typical elements of the southern European mountain landscape and a protected habitat (9260 Castanea sativa woods) according to the European Union (Directive 92/43/EEC). As an anthropogenic landscape, they require specific measures to address preservation or to guide their evolutionary trend. In the Northern Apennines, a landscape multiscalar-multitemporal approach was adopted to highlight factors that have acted on the evolution of this habitat and which still might affect either its preservation or its evolutionary dynamics. Using a diachronic GIS-approach, we analyzed old cadastral maps (drawn up 200 years ago), and aerial photographs. Both the present distribution pattern of the woody species and the incidence of important chestnut diseases were also surveyed. The factors explaining the current extent and species composition of the local chestnut forests confirm their status as an anthropogenic habitat. The present landscape distribution of chestnut woods is heavily linked to past human settlements. Chestnut blight and ink disease are more an indirect reason for past felling activities than an actual direct cause of damage to trees, because of the hypovirulence spread and the limited incidence of the ink disease. Vegetation dynamics of abandoned chestnut forests evolved only partly towards deciduous Beech and Hop Hornbeam stands, thus suggesting both the possibility of a recovery of this cultivation and the need for new criteria for its management.

Castanea sativa woods, one of the most widespread habitats of southern Europe, are included in the European Community Natura 2000 network within Sites of Community Importance (SCI). In the Northern Apennines, chestnut woods are mainly coppices derived from old chestnut orchards, and now abandoned. To describe the relationship between present chestnut structure and vegetation features, we analysed the plant diversity of chestnut woods by 143 phytosociological releves within 6 SCIs. The gradient of diversity was identified by multivariate analysis (clustering and ordination) and related to other woods such as mixed oak woods or lowest altitude Fagus sylvatica woods in order to evaluate the potential evolutionary pattern of present chestnut woods.

Question: Can landscape quality be evaluated and compared by a single numerical value using vegetation maps? Location: Northern Apennines (Italy), at about 44° N and between 10° and 11° E. Methods: Seven phytosociological vegetation maps (1:25,000), which correspond to man’s different impact on mountain landscapes, were considered. Syntaxa were classified into five degrees of naturalness, ordered according to increasing naturalness criterion: urbanized, agricultural, semi-natural, sub-natural, and natural. Naturalness vegetation maps were derived in a vectorial GIS. The degrees of naturalness of vegetation were ordered according to increasing naturalness criterion. If ci is the cumulative relative value of every mapped area of the degrees of naturalness, the sum of these cumulative values is A = ∑ ci and is a measure of vegetation artificiality. Its maximum value is Amax = n-1. The Index of Vegetation Naturalness is IVN = 1 - A / Amax , ranging from 0 to 1. Our IVN is an extension of the ILC by Pizzolotto e Brandmayr (1996) due to the ordinal character of the vegetation classification into degrees of naturalness. The maps of vegetation naturalness were also analyzed by two known metrics for the evaluation of landscape quality: TECI (Total Edge Contrast Index) and MSI (Mean Shape Index). Results: The case studies show that the IVN has a linear correlation with the decreasing area of the urbanized and agricultural vegetation types as well as with the increasing area of the highest degree of naturalness. Conclusions: The IVN could be joined to the TECI for the evaluation of naturalness of landscapes. The TECI can supply additional information about the importance of landscape ecotones. Our case studies suggest that an urbanized landscape should correspond to IVN values lower than 0.20. A natural landscape should have IVN values higher than 0.80.