Modelli interpretativi della distribuzione delle brughiere pedemontane ai fini gestionali.

Lo studio vuole contribuire alla conoscenza delle brughiere pedemontane a Calluna vulgaris (brugo) dell\u2019Italia settentrionale, ai fini di individuare elementi rilevanti per la gestione e la conservazione. L\u2019area di studio \ue8 compresa nella porzione collinare e planiziale della provincia di Como e in un breve tratto di quella di Milano. Sono stati impiegati i Generalized Linear Models per individuare quali tra le variabili ambientali interpretino pi\uf9 adeguatamente la distribuzione delle brughiere. Il modello finale indica un\u2019influenza positiva della geomorfologia (rilievi prealpini e depositi mindeliani), del bioclima (indice di Gams), della ricorrenza degli incendi e negativa del suolo (ultisols). La superficie potenzialmente occupata dalle brughiere corrisponde a circa il 7% del territorio attualmente a bosco, a prato oppure coltivato; tuttavia le brughiere si estendono oggi su meno dell\u20191% di questa superficie. La copertura della canopy influisce negativamente sulla presenza delle brughiere, con valori di Leaf Area Index tra 1.5-2.3, rilevanti una progressiva riduzione nella frequenza di brugo. Si desume pertanto il complessivo carattere relittuale di questo tipo di vegetazione, da ricollegarsi al diffuso abbandono della gestione tradizionale.Emerge in definitiva la necessit\ue0 di dare ampio impulso ad attivit\ue0 che sostengono la conservazione e il ripristino delle brughiere

La vegetazione dell\u2019istituenda Riserva Naturale \u201cOasi di Lacchiarella\u201d (Parco Agricolo Sud Milano).

\uc8 stata studiata dal punto di vista fitosociologico la vegetazione della Riserva naturale Oasi di Lacchiarella. Sono state individuate 34 cenosi vegetali, ascrivibili a 12 classi fitosociologiche: Lemnetea, Potametea, Phragmiti-Magnocaricetea, Bidentetea tripartiti, Stellarietea mediae, Oryzetea sativae, Molinio- Arrhenatheretea,Galio-Urticetea, Alnetea glutinosae, Salicetea purpureae, Rhamno-Prunetea e Querco-Fagetea. Il grado di naturalit\ue0 e il valore floristico-vegetazionale \ue8 nel complesso basso, anche nelle formazioni boschive. Le cenosi si dispongono secondo un gradiente ecologico di umidit\ue0, caratterizzato da un progressivo svincolamento dalla falda. Le cenosi di piante infestanti o ruderali seguono una propria linea dinamico-evolutiva, pressoch\ue9 indipendente da quella di interramento dei corsi d\u2019acqua; entrambe comunque convergono verso le formazioni boschive

Biomasse da praterie seminaturali come fonte di energia: un fuoco di paglia?

Biomass from seminatural grasslands as energy source: flash in the pan? - The aim of the study is to evaluate the potentiality of four seminatural herbaceous communities (grasslands of Arrhenatherion, Nardo-Agrostion tenuis, Bromion erecti and Polygono-Trisetion alliances) in the Prealpine Lombardy. We quantified the biomass production (stubble height 5 cm), the main bioenergetic features, such as ash, carbon, hydrogen and nitrogen content, and the Higher Heating Value. Biomass values vary greatly, with means between 513 (Arrhenatherion) to 227 g m-2 (Bromion erecti). The mean ash content ranges between 4.3-7.7% and mean HHV from 18.3 to 19.6 MJ kg-1. The mean energy per unit area varies between 4.5-9.5 MJ m-2.We suggest that the management of seminatural grasslands could provide biomass suitable for bioenergy production instead of common energy crops and at the same time promote conservation of habitats and their biodiversity, mostly in protected areas

Negli agro-ecosistemi, bisogna davvero scegliere fra produttività e biodiversità?

La relazione fra produttivit\ue0 e ricchezza in specie vegetali \ue8 tradizionalmente interpretata con una funzione \u2018a gobba\u2019, ovvero con i livelli pi\uf9 alti di ricchezza floristica corrispondenti agli ambienti caratterizzati da livelli intermedi di produttivit\ue0, mentre gli ambienti \u2018difficili\u2019 e quelli pi\uf9 produttivi sono da poche specie, spesso altamente dominanti. La relazione \u2018a gobba\u2019 pu\uf2 spiegare, ad esempio, perch\ue9 gli agro-ecosistemi con una gestione di tipo \u2018low-input\u2019 (es. senza l\u2019aggiunta di fertilizzanti) possono ospitare, in casi estremi, fino a 89 specie al metro quadro, oppure perch\ue9 con l\u2019aggiunta di fertilizzanti, in particolare di azoto, il numero di specie presenti subisce una consistente riduzione a causa dell\u2019instaurarsi dei fenomeni competitivi. Recentemente, uno studio condotto a livello mondiale su vegetazioni erbacee \ue8 arrivato alla conclusione che la relazione fra produttivit\ue0 e ricchezza \ue8 \u2018debole e variabile\u2019, dando il via alla speranza che sia possibile mantenere una elevata ricchezza in specie, anche in ambienti molto produttivi. Utilizzando gli stessi dati dello studio, ma analizzando specificamente il limite massimo (potenziale) della ricchezza in specie lungo il gradiente di produttivit\ue0, \ue8 possibile mettere in luce, anche per questo insieme di dati, l\u2019esistenza di un limite massimo non-lineare, statisticamente significativo, \u2018a gobba\u2019. Quest\u2019analisi conferma che l\u2019alta ricchezza in specie pu\uf2 svilupparsi in ambienti a produttivit\ue0 intermedia, sebbene non necessariamente, mentre non esistono comunit\ue0 ricche in specie a livelli di produttivit\ue0 bassi e elevati. Quindi il dilemma fra produttivit\ue0 e ricchezza in specie potenziale \ue8 un fenomeno prevedibile a livello mondiale, e la risposta alla domanda del nostro titolo \ue8: decisamente s\uec

Understanding the response of plant biodiversity to environmental perturbation using Grime’s CSR theory

Recent large-scale analyses of plant trait variation have identified two principal spectra of functional variability: 1). an \u2018economics\u2019 spectrum ranging from acquisitive species with rapid growth and thin leaves to conservative species with tough, carbon-rich leaves and, 2). for species of intermediate economics, a size spectrum characterized in part by leaf size variation (Wright et al. 2004; D\uedaz et al. 2004; Cerabolini et al. 2010; Pierce et al. 2012). Indeed, a triangle of viable leaf trait combinations is evident for the Italian flora, and has been used to produce a methodology (Pierce et al. 2013) for the classification of woody and herbaceous angiosperms, gymnosperms and pteridophytes according to CSR (competitor, stress-tolerator, ruderal) theory (Grime 2001; see also Grime & Pierce 2012). Here we review the application of CSR classification for the interpretation of the functional characteristics and assembly of a range of plant communities in Italy and worldwide. We show how CSR classification can be applied to investigate species coexistence at the centimeter scale (e.g. Pierce et al. 2014) and, by allowing a functional interpretation of macro-scale phenomena such as the relationship between biomass production and potential species richness (e.g. Cerabolini et al. 2014), how CSR strategies can allow the prediction of ecosystem and plant community responses to environmental change

Plant strategies as biological indicators of ecosystem services

Ecosystems provide services that are essential to human welfare and have been broadly classified into four types: 1). provisioning (the supply of ecosystem products including affecting food, fuel and water), 2). supporting (such as nutrient cycles and primary production that allow other ecosystem services to proceed); 3). regulating (controlling the extent of environmental processes, including climate), and 4). cultural (spiritual, recreational and scientific benefits). Ecosystem services are typically assessed using economic indicators such as perceived dollar value, but despite the importance of ecosystem properties and processes in governing ecosystem services the biotic characteristics of ecosystems do not currently play a central role ecosystem service assessment. Plants are the primary producers in terrestrial ecosystems and account for the majority of the biomass, and so the main aim of the present study was to develop a method whereby plant ecological strategies can be used to quantify and compare the four main types of ecosystem service. Sixty herbaceous plant communities, representative of a wide ecological range within the Alps and central Europe, were used to quantify differences in community-weighted mean (CWM) functional trait values, above and below ground biomass, and the quality of the species present (i.e. invasive, rare). Provisioning services were estimated as a function of the CWM values of above-ground biomass, canopy height and leaf dry weight. Supporting services were estimated as a function of leaf nitrogen content and local seasonality (flowering start and flowering period). Regulating services were calculated from the amount of sequestration in the form of below-ground dry weight and leaf carbon content. Cultural services were calculated from the relationship between the presence of protected species, black list species and the proportion of plant species in flower. Values for each ecosystem service type were compared with the CWM values of Grime\u2019s CSR plant strategies calculated from leaf economics and size traits. Grime\u2019s competitor strategy was found to be highly representative (i.e. correlated with) the degree of provisioning. The extent of ruderalism in the plant community was found to indicate the extent of supporting services, and the degree of stress-tolerance in the plant community was found to denote regulating services. Cultural services were not related to the plant strategies present. These findings underline the utility of plant CSR strategies as readily-applicable indicators of ecosystem services, at least for those that involve resource stocks and cycling, but not for cultural services

Quantifying the extent of plant functional specialization using Grime's CSR strategies

Specialization refers to a species adaptation to a restricted range of environmental conditions. While generalist species are able to exploit a wide variety of resources in a broad range of habitats, specialist species tend to have narrower niche breadths. From an evolutionary perspective, specialization is the result of a functional syndrome in which a suite of traits covary to allow the effective exploitation of specific resources. Accordingly, the measurement of specialization should be based on a multi-trait approach. In plant ecology, a well-known classification of the adaptive strategies of plants is Grime's competitor, stress tolerator, ruderal (CSR) theory in which the three principal strategies represent relatively easily measurable trait combinations from the global spectrum of plant form and function arising under conditions of competition, abiotic restriction to growth or periodic disturbance, respectively. In this paper, we thus introduce a method to summarize the functional specialization of plant species and communities by applying inequality measures to Grime's CSR strategies. The general idea is that a plant species that can be exclusively assigned to one CSR strategy can be considered a specialist (as it adopts only one adaptive strategy to access resources), while species that share functional characteristics of multiple CSR strategies can be considered more generalist. The behavior of the proposed measures is shown with one case study on the functional changes of six Alpine vegetation types ordered along a gradient, from pioneer to more stable communities

A global method for calculating plant CSR ecological strategies applied across biomes

The interface between humans and the remainder of the biosphere is characterised by rapid and drastic ecosystem perturbation, and plants are useful indicators of such changes that \u2018sit still and wait to be counted\u2019. Grime\u2019s competitor, stress-tolerator, ruderal (CSR) theory includes a practical classification method that is starting to find applications as a descriptive and predictive tool, but it is calibrated using a national flora. Using the TRY plant functional trait database (www.try-db.org), leaf economics and size data for 3068 tracheophytes (representing 198 families, six continents and all 14 principal biomes) were used to produce a multivariate analysis of trait variability, to generate a globally-calibrated CSR classification tool (\u2018Stratefy\u2019). Strategies were determined within biomes, plant families and life-forms. Fourth-corner and RLQ analyses highlighted correlations between strategies and environmental data globally and locally. Certain biomes (e.g. tropical moist and dry broadleaf forests) exhibited convergence of CSR strategies but others exhibited strategy divergence (e.g. deserts). Convergence was also evident for certain life-forms (e.g. perennial graminoids) but not others (e.g. perennial forbs). C-, S- and R-selection were variously correlated with different climatic variables worldwide depending on life-form or family. We shall include a practical demonstration of the Stratefy tool

Characterization of native hayseed: guaranteeing a seed mixture for habitat and species conservation

Here we present data on hayseed quality (purity, seed content and germination rate of seeds) for lots collected from different vegetation types and with different brush harvester types. We show that it is possible to provide labelling information with regard to hayseed quality, to calculate sowing denisties and help consumers understand the quality and performance of the product they have bought

Estimating and comparing food availability for tree-seed predators in typical pulsed-resource systems: alpine conifer forests.

Alpine conifers produce pulsed resources for the community of tree-seed consumers. Here, we describe field and statistical methods to estimate spatio-temporal variation in seed-crops in forests with different species composition. Annual and between-site variation in seed production was high and characterised by occurrence of mast-crops followed by seed-crop failure the following year. Seed-crops of different species did not fluctuate in parallel. Please see also: Plant Biosystem 143(3), Page 643 for Corrigendu