Testing an expanded set of sustainable forest management indicators in Mediterranean coppice area

A.Cutini, M.Ferretti, G.Bertini, G.Brunialti, S.Bagella, F.Chianucci, G.Fabbio, R.Fratini, F.Riccioli, C.Caddeo, M.Calderisi, B.Ciucchi, S.Corradini, F.Cristofolini, A.Cristofori, U.Di Salvatore, C.Ferrara, L.Frati, S.Landi, L.Marchino, G.Patteri, M.Piovosi, P.P.Roggero, G.Seddaiu, E.Gottardini

Although coppice forests represent a significant part of the European forest area, especially across southern Countries, they received little attention within the Sustainable Forest Management (SFM) processes and scenarios, whose guidelines have been mainly designed to high forests and national scale. In order to obtain “tailored” information on the degree of sustainability of coppices on the scale of the stand, we evaluated (i) whether the main coppice management options result in different responses of the SFM indicators, and (ii) the degree to which the considered SFM indicators were appropriate in their application at stand level. The study considered three different management options (Traditional Coppice TC, coppice under Natural Evolution NE, and coppice under Conversion to high forest by means of periodical thinning CO). In each of the 43 plots considered in the study, which covered three different European Forest Types, we applied a set of eighteen “consolidated” SFM indicators, covering all the six SFM Criteria (FOREST EUROPE, 2020) and, additionally, tested other sixteen novel indicators shaped for agamic forests and/or applicable at stand level. Results confirmed that several consolidated indicators related to resources status (Growing stock and Carbon stock), health (Defoliation and Forest damage), and socio-economic functions (Net revenue, Energy and Accessibility) were highly appropriate for evaluating the sustainability of coppice at stand level. In addition, some novel indicators related to resources status (Total above ground tree biomass), health (Stand growth) and protective functions (Overstorey cover and Understorey cover) proved to be highly appropriate and able to support the information obtained by the consolidated ones. As a consequence, a subset of consolidated SFM indicators, complemented with the most appropriate novel ones, may represent a valid option to support the evaluation of coppice sustainability at stand level. An integrated analysis of the SFM indicators showed that NE and CO display significant higher environmental performances as compared with TC. In addition, CO has positive effects also on socio-economic issues, while TC -which is an important cultural heritage and a silvicultural option that may help to keep local communities engaged in forestry – combines high wood harvesting rates with dense understory cover. Overall, each of the three management options showed specific sustainability values; as a consequence, their coexistence at a local scale and in accordance with the specific environmental conditions and the social-economic context, is greatly recommended since it may fulfill a wider array of sustainability issues.

Epiphytic lichen diversity and sustainable forest management criteria and indicators: A multivariate and modelling approach in coppice forests of Italy

Brunialti G., Frati L., Calderisi M., Giorgolo F., Bagella S., Bertini G., Chianucci F., Fratini R., Gottardini E., Cutini A.

Abstract: Epiphytic lichens represent one of the most suitable indicators of forest continuity and management, especially in the context of ancient and old-growth forests. Nevertheless, they have not yet been included among Sustainable Forest Management (SFM) indicators to which Pan-European forest policy and governance refer. In addition, currently adopted SFM indicators are mainly designed for high forests rather than coppice forests, despite the fact that today this management system covers more than 10% of the total European forests. In this study we investigated these two issues by examining epiphytic lichen diversity in three coppice forest stands, located in the two Italian regions of Tuscany and Sardinia. In particular, we addressed: i) the role of lichen diversity as SFM indicator and ii) its relationship with consolidated and new SFM indicators dealing with structural, health, biodiversity, protective and socioeconomic functions. Multivariate Factor Analysis and Generalised Linear Models were adopted for data analysis. We found that lichen diversity and the frequency of single sensitive species were mainly related to the biodiversity of plants and fungi (Criterion 4), the health and vitality of the forests (Criterion 2) and their protective functions (Criterion 5). Furthermore, our results show that the lichen species highlighted by the models may represent suitable indicators in long-term studies, especially in relation to complex and interconnected aspects of sustainable forest management. Although our findings represent a first contribute to this issue, more in-depth researches will be needed to clarify further aspects of the complex interactions among SFM indicators in the context of coppice forests.

A multi-proxy approach reveals common and species-specific features associated with tree defoliation in broadleaved species

Gottardini E., Cristofolini F., Cristofori A., Pollastrini M., Camin F., Ferretti M.

Abstract: Tree crown defoliation is the most widespread indicator of forest health and vitality in Europe. It is part of the ICP Forests Pan-European survey and it is adopted for reporting under Forest Europe. It is readily understandable and can count on fairly harmonized, long-term, large-scale data series across Europe. On the other hand, it is unspecific with respect to possible causes of damage, and its relation with tree functioning remains unclear. This study focused on European beech (Fagus sylvatica L.), Turkey oak (Quercus cerris L.), and holm oak (Quercus ilex L.), three important broadleaved forest species in southern Europe. We investigated whether and to what extent morpho-physiological (functional) leaf traits and other indicators of foliar, branch and stem health condition are associated with tree defoliation. We tested the relationship between defoliation and leaf-, branch- and stem attributes, and whether indicators of damage and functional leaf traits significantly differ (Mann-Whitney U Test) between defoliated (defoliation > 25%) and undefoliated trees (defoliation ≤ 25%). For each species, we considered one site (three to five plots each) and n = 11–19 randomly selected trees. For each tree, the following indicators were measured: crown condition (defoliation; leaf-, branch- and stem damage, in terms of extent and intensity of damage), leaf morphology (leaf thickness, leaf area, lamina length, fluctuating asymmetry, specific leaf area, damaged leaf surface), leaf physiology and chemistry (chlorophyll a fluorescence, chlorophyll content, carbon and nitrogen stable isotopes composition δ13C, δ15N, carbon/nitrogen ratio). Results show that, for the selected trees of all the three species, defoliation was positively related to the extent of damage on branches. While increasing defoliation in European beech was also accompanied by several significant differences at leaf level (i.e., leaf damage, leaf volume, dry weight, carbon/nitrogen ratio and photosynthetic efficiency), for Turkey oak and holm oak the significant differences between defoliated and undefoliated trees were limited to damage on branches (both species).

Indicators of sustainable forest management to evaluate the socio-economic functions of coppice in Tuscany, Italy

Autori: Riccioli F., Fratini R., Marone E., Fagarazzi C., Calderisi M., Brunialti G.

Abstract: Due to several ecosystem services provided to the community, the multifunctional management of forests has acquired an important role over the years. The current Sustainable Forest Management (SFM) guidelines are based on planning programmes which are able to achieve targets from socio-economic and environmental points of view. In this paper, SFM indicators have been studied and compared to estimate the sustainability of three coppice options, from both an economic and a socio-environmental viewpoint. Each indicator was studied in relationship to the treatment and to the considered areas. The results of the statistical analysis show differences among treatments, and the possible correlations between the indicators. Moreover, by using principal component analysis (PCA), the correlations between the indicators were analysed, while the ways in which they influenced the examined sites were also considered. In particular, specific homogeneous clusters separating the observed sites were observed based on treatment and geographical gradient. Overall, the set of indicators used has proven to be effective when carrying out an evaluation of the existing types of forest management based on the analysis of three fundamental aspects of the SFM.

Long-term comparison of in situ and remotely-sensed leaf area index in temperate and mediterranean broadleaved forests

Autori: C. Tattoni, F. Chianucci, M. Grotti, R. Zorer, A. Cutini, D. Rocchini.

Abstract: Monitoring vegetation structure and functioning is critical for modelling terrestrial ecosystems and energy cycles. Leaf area index (LAI) is an important structural property of vegetation used in many land-surface, climate, and forest monitoring applications. Remote sensing provides a unique way to obtain estimates of leaf area index at spatially extensive areas. However, the analysis and extraction of quantitative information from remotely-sensed data require accurate cross-calibration with in situ forest measurements, which are generally spatially- and temporally-limited, thereby limiting the ability to compare the seasonal dynamic patterns between field and remotely-sensed time series. This is particularly relevant in temperate broadleaved forests, which are characterized by high level of complexity, which can complicate the retrieval of vegetation attributes from remotely-sensed data. In this study, we performed a long-term comparison of MODIS LAI products with continuous in situ leaf area index measurements collected monthly in temperate and Mediterranean forests from 2000 to 2016. Results indicated that LAI showed a good correlation between satellite and ground data for most of the stands, and the pattern in seasonal changes were highly overlapping between the timeseries. We conclude that MODIS LAI data are suitable for phenological application and for up-scaling LAI from the stand level to larger scales.

Multi-temporal dataset of stand and canopy structural data in temperate and Mediterranean coppice forests

Autori: Chianucci F., Ferrara C., Bertini G., Fabbio G., Tattoni C., Rocchini D., Corona P., Cutini A.

Abstract: We provided long-term stand and canopy structural data from permanent monitoring plots representative of some most diffuse temperate and Mediterranean forests, under different coppice management regimes. Periodic inventories were performed in the surveyed plots since the 1970s. Annual litterfall production and its partitioning (leaf, woody, reproductive parts) and optical canopy measurements using the LAI-2000 Plant Canopy Analyzer were performed every year in fully equipped plots since the 1990s. These data can be used for evaluating the influence of coppice management in the stand and canopy structure, the parametrization of radiative transfer models that require accurate ground truth data, and the calibration of high to medium resolution remotely sensed data. Dataset access is at https://doi.org/10.17632/z8zm3ytkcx.2. Associated metadata is available at https://agroenvgeo.data.inra.fr/geonetwork/srv/eng/catalog.search#/metadata/2bd2d77f-3cf8-43da-b1b5-9f8196dc017f.

Coppice silviculture: are laws and regulations in line with current conditions in Italy?

Autori: A. Cutini, W. Mattioli, F. Roggero, G.Fabbio, R. Romano, V. Quatrini, P. Corona

Abstract: Despite a less intensive management in the recent decades, coppices still cover a large part of Italian woodlands. Currently, they are characterized by relatively large wood volumes, especially with respect of those stands classified as “aged”. The current European and national strategies to reduce the use of fossil fuels and the related increasing demand of renewable bio-energy sources are giving a new boost to the coppice system, so that the need for an improved management of these stands is emerging. Under this perspective, this note highlights the opportunity for an overall revision of current forest laws and regulations at regional level in Italy, in order to embed recent scientific achievements and harmonize some aspects such as definitions, rotation, conversion to high stands, standards, cut size and administrative procedures.

Coppice today: which management beyond definitions?

Autori: G. Fabbio, A. Cutini

Abstract: The economical-social change, the competitiveness and “modernity” of fossil fuels, their prompt diffusion are the concurrent factors that heavily reduced the use of coppice firewood and charcoal since the fifties of the last century. Therefore, a shift took place in the last 60 years from the homogeneous area made of intensively managed, young stands to the more and more differentiated standing crops, as for structural features, growing stocks and growth dynamics, even though all of them originated from a common matrix. Nowadays, the former coppice area includes stands managed under lengthened rotations, outgrown coppices, the coppice conversion into high forest. The 2005 National Forest Inventory reported that 87% of standing crops was included in the age-classes 20-40 and over 40 years, with variable percentages according to tree species, from beech up to thermophilous oaks. Here, the basis of historical judgment on the coppice system, the reasons underlying the outgrown coppice establishment, the current standards of cultivation under even doubled rotations, are critically analyzed. The current demand to reduce the use of fossil fuels by renewable bio-energy sources and to face up the effects of climate change (unpredictability, rainfall reduction, higher air temperature, prolonged droughts, water stress, fire risk) give a new boost to the coppice system. Main goals today are to: (i) optimize the capacity of firewood production to reduce the heavy deficit at the country level; (ii) make the best use of the regeneration ability inherent to the system against the more sensitive regeneration from seed in the changing environment. The positive growth trend, the maintenance of resprouting ability as well as of vital stools density in the outgrown coppice area, address to a sustainable increase of rotations up to the age of 50 years, as already highlighted by a few regional regulations. It would allow the recovery of a current volume increment of 1-1.5 M m3 to internal firewood production. Unsuitable stand locations or bio-ecological conditions as well as stands already under conversion into high forest are obviously excluded. The approach to coppice system maintenance within the variable territorial context, the possible innovation and the definition of flexible silvicultural models are then outlined. The useful updating and harmonization of forest regulations are finally recalled.

Measuring $\beta$-diversity by remote sensing: a challenge for biodiversity monitoring. Methods in Ecology and Evolution

Autori: Rocchini, D., Luque, S., Pettorelli, N., Bastin, L., Doktor, D., Faedi, N., Feilhauer, H., F\'{e}ret, J.-B., Foody, G.M., Gavish, Y., Godinho, S., Kunin, W.E., Lausch, A., Leit\~{a}o, P.J., Marcantonio, M., Neteler, M., Ricotta, C., Schmidtlein, S., Vihervaara, P., Wegmann, M., Nagendra, H. (2018).

Abstract: Biodiversity includes multiscalar and multitemporal structures and processes, with different levels of functional organization, from genetic to ecosystemic levels. One of the mostly used methods to infer biodiversity is based on taxonomic approaches and community ecology theories. However, gathering extensive data in the field is difficult due to logistic problems, especially when aiming at modelling biodiversity changes in space and time, which assumes statistically sound sampling schemes. In this context, airborne or satellite remote sensing allows information to be gathered over wide areas in a reasonable time. Most of the biodiversity maps obtained from remote sensing have been based on the inference of species richness by regression analysis. On the contrary, estimating compositional turnover β‐diversity) might add crucial information related to relative abundance of different species instead of just richness. Presently, few studies have addressed the measurement of species compositional turnover from space. Extending on previous work, in this manuscript, we propose novel techniques to measure β‐diversity from airborne or satellite remote sensing, mainly based on: (1) multivariate statistical analysis, (2) the spectral species concept, (3) self‐organizing feature maps, (4) multidimensional distance matrices, and the (5) Rao's Q diversity. Each of these measures addresses one or several issues related to turnover measurement. This manuscript is the first methodological example encompassing (and enhancing) most of the available methods for estimating β‐diversity from remotely sensed imagery and potentially relating them to species diversity in the field.

Remotely sensed spatial heterogeneity as an exploratory tool for taxonomic and functional diversity study. Ecological Indicators

Autori: Rocchini, D., Bacaro, G., Chirici, G., Da Re, D., Feilhauer, H., Foody, G.M., Galluzzi, M., Garzon-Lopez, C.X., Gillespie, T.W., He, K.S., Lenoir, J., Marcantonio, M., Nagendra, H., Ricotta, C., Rommel, E., Schmidtlein, S., Skidmore, A.K., Van De Kerchove, R., Wegmann, M., Rugani, B. (2018).

Abstract: Assessing biodiversity from field-based data is difficult for a number of practical reasons: (i) establishing the total number of sampling units to be investigated and the sampling design (e.g. systematic, random, stratified) can be difficult; (ii) the choice of the sampling design can affect the results; and (iii) defining the focal population of interest can be challenging. Satellite remote sensing is one of the most cost-effective and comprehensive approaches to identify biodiversity hotspots and predict changes in species composition. This is because, in contrast to field-based methods, it allows for complete spatial coverages of the Earth's surface under study over a short period of time. Furthermore, satellite remote sensing provides repeated measures, thus making it possible to study temporal changes in biodiversity. While taxonomic diversity measures have long been established, problems arising from abundance related measures have not been yet disentangled. Moreover, little has been done to account for functional diversity besides taxonomic diversity measures. The aim of this manuscript is to propose robust measures of remotely sensed heterogeneity to perform exploratory analysis for the detection of hotspots of taxonomic and functional diversity of plant species.

The recreational value of forests under different management systems

Riccioli F., Fratini R., Marone E., Boncinelli F., Tattoni C., Rocchini D.

Poster on some FutureForCoppices Project results presented at the IUFRO Conference "3rd Restoring Forests: Regeneration and Ecosystem Function for the Future" Lund (Sweden) - 12-14 September 2017

Spatio-ecological complexity measures in GRASS GIS.

Rocchini, D., Petras, V., Petrasova, A., Chemin, Y., Ricotta, C., Frigeri, A., Landa, M., Marcantonio, M., Bastin, L., Metz, M., Delucchi, L., Neteler, M.

Good estimates of ecosystem complexity are essential for a number of ecological tasks: from biodiversity estimation, to forest structure variable retrieval, to feature extraction by edge detection and generation of multifractal surface as neutral models for e.g. feature change assessment. Hence, measuring ecological complexity over space becomes crucial in macroecology and geography. Many geospatial tools have been advocated in spatial ecology to estimate ecosystem complexity and its changes over space and time. Among these tools, free and open source options especially offer opportunities to guarantee the robustness of algorithms and reproducibility. In this paper we will summarize the most straightforward measures of spatial complexity available in the Free and Open Source Software GRASS GIS, relating them to key ecological patterns and processes

http://dx.doi.org/10.1016/j.cageo.2016.05.006

Boosting the use of spectral heterogeneity in the impact assessment of agricultural land use on biodiversity

Rugani, B., Rocchini, D. (2017)

No consensus has been yet achieved among Life Cycle Assessment (LCA) practitioners on how to assess the impact on biodiversity due to land uses and land use changes, in particular with regard to agricultural areas. In the domain of nature conservation and landscape ecology, spectral heterogeneity (SH) derived from remotely sensed imagery is considered a viable proxy for species diversity detection. The assessment rationale is based on the âspectral variation hypothesisâ: the higher the spectral variability, the higher the ecological heterogeneity and species community diversity, occupying different niches. Our hypothesis is that SH can be effective to improve or complement current Life Cycle Impact Assessment - LCIA practice on biodiversity loss evaluation driven by land use. Hence, we aim here to explore this assumption by computing SH at a local scale of crops cultivation in Southern Alps (Trentino province, Italy), and then combining this information with land use over 30 years. We observe and analyse the relationships between land cover maps and habitat heterogeneity at different time and spatial resolutions. This allows us to argue about the robustness of SH to be a potential surrogate of environmental nuances for species variability detection in LCIA.

Satellite remote sensing to monitor species diversity: potential and pitfalls

Rocchini, D., Boyd, D.S., Féret, J.B., Foody, G.M., He, K.S., Lausch, A., Nagendra, H., Wegmann, M., Pettorelli, N.

Assessing the level of diversity in plant communities from field-based data is difficult for a number of practical reasons: (1) establishing the number of sampling units to be investigated can be difficult; (2) the choice of sample design can impact on results; and (3) defining the population of concern can be challenging. Satellite remote sensing (SRS) is one of the most cost-effective approaches to identify biodiversity hotspots and predict changes in species composition. This is because, in contrast to field-based methods, it allows for complete spatial coverages of the Earthâs surface under study over a short period of time. Furthermore, SRS provides repeated measures, thus making it possible to study temporal changes in biodiversity. Here, we provide a concise review of the potential of satellites to help track changes in plant species diversity, and provide, for the first time, an overview of the potential pitfalls associated with the misuse of satellite imagery to predict species diversity. Our work shows that, while the assessment of alpha-diversity is relatively straightforward, calculation of beta-diversity (variation in species composition between adjacent locations) is challenging, making it difficult to reliably estimate gamma-diversity (total diversity at the landscape or regional level). We conclude that an increased collaboration between the remote sensing and biodiversity communities is needed in order to properly address future challenges and developments.

http://dx.doi.org/10.1002/rse2.9

2D visualization captures the local heterogeneity of oxidative metabolism across soils from diverse land-use.

Rubol, S., Dutta, T., Rocchini, D. (2016)

Fine-scale processes in soils affect large-scale phenomena by controlling mixing and reaction rates, yet technological constraints have hampered the collection of micro-scale kinetic data. As a result, limited information is available on the magnitude of fine-scale biogeochemical rates and their temporal and spatial pattern in response to environmental perturbations. In this work we investigate the spatio-temporal dynamics in oxidative microbial activity and the development of anoxic micro zones (i.e., anoxic hot-spots) at the microscopic level (μm - cm). These analyses rely on novel non-invasive & non-destructive optodes, which are able to capture real-time imaging of oxygen concentrations over time at an interval of twenty seconds. Results showed that labile carbon addition resulted in maximum rates of local metabolic activity within a few minutes (5 to 15) and led to the subsequent formation of anoxic hot-spots. Different areas within a given soil sample presented up to one order of magnitude variation in metabolic rate values. As a result, oxic and anoxic micro-zones coexisted closely. The relationship between oxygen concentrations and heterogeneity of oxidative metabolism resulted in an initial increase in metabolic heterogeneity over time followed by a decrease when anoxic conditions dominated. A similar link was found by comparing metabolic activity and its heterogeneity across a range of soil types. These results demonstrate that the microbial activity and hot-spot development can be monitored by using a non-invasive quantitative imaging system that allows real-time monitoring of spatial oxygen distribution. We conclude that local dynamics of heterogeneity in space and time at the fine-scale present the same functional behavior encountered in most ecosystems at the landscape-scale.

http://dx.doi.org/10.1016/j.scitotenv.2016.06.252

Exploring the relationship between remotely-sensed spectral variables and attributes of tropical forest vegetation under the influence of local forest institutions.

Agarwal, S., Rocchini, D., Marathe, A., Nagendra, H. (2016)

Conservation of forests outside protected areas is essential for maintaining forest connectivity, which largely depends on the effectiveness of local institutions. In this study, we use Landsat data to explore the relationship between vegetation structure and forest management institutions, in order to assess the efficacy of local institutions in management of forests outside protected areas. These forests form part of an important tiger corridor in Eastern Maharashtra, India. We assessed forest condition using 450 randomly placed 10 m radius circular plots in forest patches of villages with and without local institutions, to understand the impact of these institutions on forest vegetation. Tree density and species richness were significantly different between villages with and without local forest institutions, but there was no difference in tree biomass. We also found a significant difference in the relationship between tree density and NDVI between villages with and without local forest institutions. However, the relationship between species richness and NDVI did not differ significantly. The methods proposed by this study evaluate the status of forest management in a forest corridor using remotely sensed data and could be effectively used to identify the extent of vegetation health and management status.

http://dx.doi.org/10.3390/ijgi5070117

Incorporating spatial autocorrelation in rarefaction methods: implications for ecologists and conservation biologists.

Bacaro, G., Altobelli, A., Camelletti, M., Ciccarelli, D., Martellos, S., Palmer, M.W., Ricotta, C., Rocchini, D., Scheiner, S.M., Tordoni, E., Chiarucci, A. (2016)

Recently, methods for constructing Spatially Explicit Rarefaction (SER) curves have been introduced in the scientific literature to describe the relation between the recorded species richness and sampling effort and taking into account for the spatial autocorrelation in the data. Despite these methodological advances, the use of SERs has not become routine and ecologists continue to use rarefaction methods that are not spatially explicit. Using two study cases from Italian vegetation surveys, we demonstrate that classic rarefaction methods that do not account for spatial structure can produce inaccurate results. Furthermore, our goal in this paper is to demonstrate how SERs can overcome the problem of spatial autocorrelation in the analysis of plant or animal communities. Our analyses demonstrate that using a spatially-explicit method for constructing rarefaction curves can substantially alter estimates of relative species richness. For both analyzed data sets, we found that the rank ordering of standardized species richness estimates was reversed between the two methods. We strongly advise the use of Spatially Explicit Rarefaction methods when analyzing biodiversity: the inclusion of spatial autocorrelation into rarefaction analyses can substantially alter conclusions and change the way we might prioritize or manage nature reserves.

http://dx.doi.org/10.1016/j.ecolind.2016.04.026

Long-term response to thinning in a beech (Fagus sylvatica L.) coppice stand under conversion to high forest in Central Italy.

Chianucci F., Salvati L., Giannini T., Chiavetta U., Corona P., Cutini A. (2016)

European beech (Fagus sylvatica L.) forests have a long history of coppicing, but the majority of formerly managed coppices are currently under conversion to high forest. The long time required to achieve conversion requires a long-term perspective to fully understand the implication of the applied conversion practices. In this study, we showed results from a long-term (1992–2014) case-study comparing two management options (natural evolution and periodic thinning) in a beech coppice in conversion to high forest. Leaf area index, litter production, radiation transmittance and growth efficiency taken as relevant stand descriptors, were estimated using both direct and indirect optical methods. Overall, results indicated that beech coppice showed positive and prompt responses to active conversion practices based on periodic medium-heavy thinning. A growth efficiency index showed that tree growth increased as the cutting intensity increased. Results from the case study supported the effectiveness of active conversion management from an economic (timber harvesting) and ecological (higher growth efficiency) point of view.

http://dx.doi.org/10.14214/sf.1549

Measuring Rao’s Q diversity index from remote sensing: An open source solution

Duccio Rocchini, Matteo Marcantonio, Carlo Ricotta

Measuring biodiversity is a key issue in ecology to guarantee effective indicators of ecosystem health at different spatial and time scales. However, estimating biodiversity from field observations might present difficulties related to costs and time needed. Moreover, a continuous data update for biodiversity moni-toring purposes might be prohibitive. From this point of view, remote sensing represents a powerful tool since it allows to cover wide areas in a relatively low amount of time. One of the most common indicators of biodiversity is Shannon’s entropy H_ , which is strictly related to environmental heterogeneity, and thus to species diversity. However, Shannon’s entropy might show drawbacks once applied to remote sensing data, since it considers relative abundances but it does not explicitly account for distances among pixels’ numerical values. In this paper we propose the use of Rao’s Q applied to remotely sensed data, providing a straightforward R-package function to calculate it in 2D systems. We will introduce the theoretical rationale behind Rao’s index and then provide applied examples based on the proposed R function.

http://dx.doi.org/10.1016/j.ecolind.2016.07.039