**2. Vegetation of the agroecosystem**

#### **2.1 Study of the plant landscape**

334 Ecosystems Biodiversity

biodiversity levels are high and their maintenance is strictly linked to the management practices adopted by man, whereby the traditional activities favour such biodiversity. On the other hand, the agricultural systems that are subjected to intensive cultivation that are generically represented in the plain or low hilly areas are poorer overall in landscape elements that are useful for the protection, survival and reproduction of the wild animal and

Over the last ten years, a greater environmental awareness has guided public opinion towards a re-evaluation of the role of man in the management of the agroecosystems on which the maintenance of a satisfactory level of biological complexity depends. From the agricultural point of view, we have therefore passed from a largely productive approach to management strategies that are aimed at an increase in the quality of the products and the

Today, the recovery of ancient cultivated varieties or autochthonous races is encouraged and has taken on crucial importance from the politico-economic and social points of view within specific rural contexts. The appreciation and commercialisation of these products, together with the official recognition that guarantees their quality, can return the original identity to the rural territories of high landscape value. Given their specific characteristics, such territories would have been progressively excluded from the commercial networks of

The return of the original production and local traditions is allowed by the measures introduced with the regulatory practices that are a part of agriculture today. The Common Agricultural Policy that is applied at a regional level through the Regional Plans for Rural Development, and the regulation of the Cross Compliance favour the modernisation of the sector and of the individual farms, the improvement of the socio-economic conditions of the rural populations, and the protection of the environment within which these

In this sense, the farms take on a multifunctional role: as well as providing quality production, and in some cases services such as refection, or educational or recreational activities (e.g., holiday and educational farms), are especially required to manage and maintain their environment. This guarantees periodic maintenance of the non-productive infrastructure, the presence of which has fundamental importance in the correct ecological

This non-productive infrastructure of the agricultural landscape serves many functions, among which there is the conservation of biodiversity, the management and filtering of the water, the protection from pollution, erosion, and hydrogeological problems, and the fixation of CO2. Moreover, these constitute an excellent indirect opportunity for the farms, because they allow the farms themselves to identify with a varied productive context that is

It is obvious that the actions of those who operate in agriculture must be evaluated periodically in order to verify the effective validity and efficacy of their practices. For this, there is the need for indicators or indexes that provide a sufficiently detailed measure of the

With the present study, following on from a description of the main vegetation typologies of an agroecosystem context, we will illustrate a method for the evaluation of the functionality of the rural contexts that we have applied in past years to various territories examined. The system that we have adopted is based on vegetation analysis and on the application of

plant species.

rural environment.

intensive and industrialised agriculture.

populations live and work.

functioning of the agroecosystem.

rich in life and well maintained.

quality of the rural environment.

The study of the vegetation represents the best-suited method for interpretation of the ecological potential of a territorial context. The arrival and establishing of one specific vegetational typology rather than another are phenomena that are mainly linked to the particularities of the climate, pedology and use of a specific area. The phytosociological method is a rapid and efficient analytical procedure based on floristic and statistical measures that is widely used throughout the World (Westhoff & Van der Maarel, 1978; Gèhu & Rivas-Martinez, 1981).

It is based on phytosociological sampling that is carried out in the field following the individuation of an ecologically homogeneous area. It consists in the forming of a list of all of the plants that are found in the chosen site and the assignment of coverage and interactive values to all of these following specifically designed scales (range, + 5 for the coverage, and 1 5 for the interactions). A re-evaluation of the relevés of the area then follows, through comparisons with Tables of previously defined relevés or through statistical analyses, with the aim of defining the plant associations.

The association is the basic unit upon which phytosociology is based, which is found within a unit of territory that is ecologically homogeneous and is represented by significantly repeated floristic components. The phytocoenoses are organised according to a hierarchical system. The upper level of the association is represented by the alliance, which in turn is included in an order. At the apex of the hierarchical organisation there is the vegetation class, which expresses the structure, evolution and phytogeographical significance of the various typologies that are referred to it.

The identification and description of the plant communities represents the first level of investigation, which goes under the name of classical phytosociology analysis. The study of the vegetation is, however, expressed according to two further levels: synphytosociological and geosynphytosociological.

The synphytosociological investigation is based on the identification of vegetation series. This phase studies the dynamic relationships between the various associations within the same sigmetum, which consists of a portion of the territory characterised by the same pedoclimatic particularities and within which there is therefore space for a single typology of potential vegetation (the climax). This level allows identification of the interactions between the different phytocoeneses, as evolutive or regressive, that occur within a "tessella" of ecologically homogeneous territory (Biondi, 1996). The tessella therefore represents the biogeographical environmental unit of a hypothetical mosaic and it is defined on the basis of various factors: the nature of the substrate, the altitude, the exposure, and the slope.

Within each tessella, the associations are organised in serial interactions and the areas occupied by the same plant communities are not constant with time, but can vary according to the management practices that are followed.

Environmental Evaluation and Monitoring of Agro-Ecosystems Biodiversity 337

sector of the Italian peninsula, from the region of Fruili Venezia Giulia to Molise (Fig. 1). The geographical localisation and the pedoclimatic and morphological characteristics of the areas under study are summarised later. Brief descriptions of the ecological characteristics and the evolutive significance of the syntaxonomic classes are given. Moreover, the main orders are illustrated, and some of the vegetational typologies are described that can be

The classes are ordered according to their physiognomic and ecological characteristics: the serial typologies (therophyte vegetation, perennial grasslands, forest edges, shrub layers and mantles, woods) have been differeniated from the category relative to the acquatic

The plant communities that have mainly therophyte species are referred to the class *Stellarietea*, and they are characterised by an annual cycle and reproduction by seed (Rivas

This syntaxon includes phytocoenoses of commensals of annual-seeded crops, as both autumn to winter and spring to summer, and initial and immature grasslands that are seen under conditions of recurring disturbance, mainly by man. This disturbance can be caused

In a serial context, the class *Stellarietea* occupies the first evolutionary step. The phytocoenoses of this syntaxonomic unit take on pioneering characters and tend to be the first to grow on bare substrata. In these communities, exotic species or species with a large

by herbicides or by movement or removal of the surface layer of the soil.

typically seen in the agricultural ecosystems.

Fig. 1. Map of the study areas.

**2.3 The therophyte vegetation** 

**2.3.1 Class** *Stellarietea*

Martinez et al., 2002).

azonal vegetation (both herbaceous and arboreal).

The third level of analysis is known as geosynphytosociology, and it studies the interactions between typologies of the vegetation across different geographical environmental units. In this case, these interactions are defined as chain interactions, and the evolution of a coenosis towards another in chain contact is never expected to occur, because two such coenoses occupy landscape tessellae with different vegetational potentials.

The method has an important predictive role in the ecological analysis of the landscape and has particular use in the planning and management of the territory. It can be used on different scales and allows generalisable results to be obtained. Depending on historic data, it allows the performing of diachronic analyses. It has been adopted by the European Community as the official means for identification and description of the habitats that warrant protection according to Directive 92/43/EEC.

This investigation system constitutes, moreover, the basis of our analysis of the functionality of the agroecosystems. This has been possible following the application of the floristic-vegetational indexes that are now presented (Taffetani & Rismondo, 2009; Rismondo *et al*., 2011).

#### **2.2 The rural ecomosaic**

As already discussed in the introduction, the agroecosystem normally appears within a context that has been modelled and strongly influenced by man. Although recognising the existence of agricultural realities that are greatly different both from the point of view of the vegetational potentiality and that relative to the productive uses and the impact of man, it is still possible to say that generally the rural ecomosaic is formed by an alternation between various tesserae that can be differentiated one from the other as a function of their ecological significance.

In the agricultural landscape, a succession of areas can be seen that are cultivated with techniques that are more or less intensive, as the plots, alternating with diffuse semi-natural elements that gradually tend to occupy more space in passing on to contexts with less human impact. These are usually found in the zones that are less accessible and where mechanical tillage is less possible, and they are more frequent in the agricultural areas that are less intensively cultivated or are subjected to particular protection regulations.

The semi-natural elements are identified by formations such as rows of trees, hedges, small woods (either spontaneous or planted by man) and their ecotones, grasslands, abandoned fields, herbaceous strips along ditches, slopes, small farm tracks, edges of fields and ditches, and riparian formations.

The agricultural areas that are more variegated and richer from a naturalistic point of view usually occupy the zones in which the local population knew how to maintain and value traditional techniques and production in equilibrium with the potentiality of the surrounding environment. However, more and more often the areas that are disadvantaged from a productive point of view tend to be progressively abandoned; this allows evolution of grass coenoses, an increase in the areas of the shrub and tree communities, and the consequent loss of ecosystem variety. All of the units making up the agroecosystem mosaic take on their own functional significance within the context analysed. This significance is the fruit of all of the previous progressive productive uses, and it can be photographed in a clear and precise way, with the identification of the floristic-structural characteristics and with the subsequent syntaxonomic classification of the investigated areas.

In this section of the present study, the vegetation classes will be presented that are more represented in the rural systems that are under analysis. These last refer to the Adriatic

The third level of analysis is known as geosynphytosociology, and it studies the interactions between typologies of the vegetation across different geographical environmental units. In this case, these interactions are defined as chain interactions, and the evolution of a coenosis towards another in chain contact is never expected to occur, because two such coenoses

The method has an important predictive role in the ecological analysis of the landscape and has particular use in the planning and management of the territory. It can be used on different scales and allows generalisable results to be obtained. Depending on historic data, it allows the performing of diachronic analyses. It has been adopted by the European Community as the official means for identification and description of the habitats that

This investigation system constitutes, moreover, the basis of our analysis of the functionality of the agroecosystems. This has been possible following the application of the floristic-vegetational indexes that are now presented (Taffetani & Rismondo, 2009;

As already discussed in the introduction, the agroecosystem normally appears within a context that has been modelled and strongly influenced by man. Although recognising the existence of agricultural realities that are greatly different both from the point of view of the vegetational potentiality and that relative to the productive uses and the impact of man, it is still possible to say that generally the rural ecomosaic is formed by an alternation between various tesserae that can be differentiated one from the other as a

In the agricultural landscape, a succession of areas can be seen that are cultivated with techniques that are more or less intensive, as the plots, alternating with diffuse semi-natural elements that gradually tend to occupy more space in passing on to contexts with less human impact. These are usually found in the zones that are less accessible and where mechanical tillage is less possible, and they are more frequent in the agricultural areas that

The semi-natural elements are identified by formations such as rows of trees, hedges, small woods (either spontaneous or planted by man) and their ecotones, grasslands, abandoned fields, herbaceous strips along ditches, slopes, small farm tracks, edges of fields and ditches,

The agricultural areas that are more variegated and richer from a naturalistic point of view usually occupy the zones in which the local population knew how to maintain and value traditional techniques and production in equilibrium with the potentiality of the surrounding environment. However, more and more often the areas that are disadvantaged from a productive point of view tend to be progressively abandoned; this allows evolution of grass coenoses, an increase in the areas of the shrub and tree communities, and the consequent loss of ecosystem variety. All of the units making up the agroecosystem mosaic take on their own functional significance within the context analysed. This significance is the fruit of all of the previous progressive productive uses, and it can be photographed in a clear and precise way, with the identification of the floristic-structural characteristics and with the

In this section of the present study, the vegetation classes will be presented that are more represented in the rural systems that are under analysis. These last refer to the Adriatic

are less intensively cultivated or are subjected to particular protection regulations.

subsequent syntaxonomic classification of the investigated areas.

occupy landscape tessellae with different vegetational potentials.

warrant protection according to Directive 92/43/EEC.

Rismondo *et al*., 2011).

**2.2 The rural ecomosaic** 

and riparian formations.

function of their ecological significance.

sector of the Italian peninsula, from the region of Fruili Venezia Giulia to Molise (Fig. 1). The geographical localisation and the pedoclimatic and morphological characteristics of the areas under study are summarised later. Brief descriptions of the ecological characteristics and the evolutive significance of the syntaxonomic classes are given. Moreover, the main orders are illustrated, and some of the vegetational typologies are described that can be typically seen in the agricultural ecosystems.

The classes are ordered according to their physiognomic and ecological characteristics: the serial typologies (therophyte vegetation, perennial grasslands, forest edges, shrub layers and mantles, woods) have been differeniated from the category relative to the acquatic azonal vegetation (both herbaceous and arboreal).

Fig. 1. Map of the study areas.
