Roberto Canullo

Patterns of functional clonal traits and clonal growth modes in contrasting grasslands in the central Apennines, Italy.

Abstract Aim: Patterns of plant functional traits related to clonality (clonal growth modes; CGM) in plant communities were studied and hypotheses on the importance of the selected traits in plant communities supported by soils differing in moisture and nutrient status were tested. Material and Methods: Selected plant functional traits, such as the position of the mother-daughter plants connections, length of spacers, frequency of multiplication, persistency of ramets connections, presence of storage organs and bud protection were studied in two contrasting plant communities (xeric and mesic abandoned pastures) typical of central Apennines, Italy. Results and Discussion: Clonality was shown to be of great importance in both mesic and xeric grasslands. The major differences between the two communities were due to the dominant CGMs: turf graminoids (having effective protection of growth meristems in dense tussocks) dominated xeric grasslands, while rhizomatous graminoids (typical of competitive resource-rich environments) dominated mesic grasslands. Below-ground CGOs (clonal growth organs), shorter spacers, higher multiplication potential, permanent ramet connection, large bud bank and increased importance of bud protection were found to be of importance in water stressed xeric grassland. Contrary to our expectations, the mesic (less stressed) grasslands have the higher number of clonal plants possessing storage organs. Nomenclature: Pignatti (1982) for taxa; Venanzoni & Kwiatkowski (1995) for the syntaxa mentioned in Table 1. Abbreviations: CGM = Clonal growth mode; CGO = Clonal growth organ.

Patterns of Clonal Growth Modes Along a Chronosequence of Post-Coppice Forest Regeneration in Beech Forests of Central Italy

Forest coppicing leads to changes in composition of the herbaceous understory through soil disturbance and alteration of the light regime. While the role of seed dispersal traits at the start of succession after coppicing has been extensively studied, the role of persistence traits such as clonal growth and bud banks is not yet sufficiently understood. To gain better understanding of this role, we studied the patterns of clonal growth organs and related clonal traits of species in a series of coppiced beech forests of the Central Apennines (Marches region, Italy) in various stages of recovery after the last coppicing event. We conducted stratified random sampling and established a chronosequence of recovery stages based on stand age (reflecting the number of years since the last coppicing). The beech stands were classified into three age groups (Post-logged, Recovering, and Old-coppice stands) according to the characteristic stages of beech coppice dynamics. Clonal growth organs and the corresponding clonal traits of plants in the forest understory vegetation were assessed with the help of a CLO-PLA1 database. We found no significant change in the proportion of clonal species along the studied chronosequence. In contrast, most of the traits and about the half of the clonal growth organs showed correlation with stand age or preference for a certain habitat (i.e., stage of regeneration). Clonal and bud bank traits proved to play an important role in the persistence of species subjected to forest coppicing cycles in the studied area.

La recolonisation des champs abandonnés par l'espèce forestière Anemone nemorosa L.: I - Distribution et dynamique

Abstract The recolonization of abandoned fields by means of the forest species Anemone nemorosa L.: I - Distribution and dynamics. - Anemone nemorosa like pioneer of the forest recreation on previously cultivated areas was investigated. The investigation was carried out on permanent study areas on the Bialowieza Primeval Forest and Bialowieza clearing. A map of distribution and dynamics of A. nemorosa is given. Results show that the state of vegetation is the most important factor limiting the distribution of this species. The comparison of three populations of A. nemorosa (in Tilio-Carpinetum forest, in shrubs and grassland zones) demonstrate some different characteristics on the individuals in pioneer conditions.

Fine‐scale spatial pattern analysis of the herb layer of woodland vegetation using information theory

Abstract The scale dependence of vegetation patterns and processes is generally accepted, but few long‐term studies have directly and explicitly considered scaling aspects in their sampling designs. In order to optimise data collection, particular emphasis must be given to the spatial scales at which maximum diversity, maximum heterogeneity, and maximum spatial dependence appear. The spatial pattern of the herb layer of woodland vegetation (old Quercus cerris coppice) in the central Apennines (Italy) was studied using information theory models. Inside a permanent plot, ground layers of vegetation were sampled along three circular transects. Data were analysed along a series of scales between 0.1 and 60 m. Detected patterns were tested against neutral models generated by Monte‐Carlo simulations. The maximum diversity of species combinations was found between 1 and 4 m, while the maximum heterogeneity and the highest degree of spatial dependence of populations appeared around 10 m. Complete randomisation de...

Spatial patterns of plant species, guilds and biological types in the regenerative phase of a beech coppice (Torricchio Mountain Nature Reserve, Apennines, Italy).

Abstract This work explores and compares horizontal models of some textural categories in the herb layer of an aged beech coppice wood in Torricchio Nature Reserve, Apennines (Italy). Vegetation was analysed using multi-species models of information theory, considering the relationships of diversity and spatial dependence in the categories. Frequency data on circular transects were analysed along a series of scales. Detected patterns were tested against neutral models by Monte-Carlo simulations. Most of the species show a high degree of aggregation and heterogeneity levels which were often maximal over 10 m. The guilds have a much weaker structure. The life forms have the most spatially aggregated groups, and intermediate spatial dependence and units complexity. These results show that the spatial distribution of the understory is guided by effects of previous management that have modified the community structure, creating static centres of shoot development, and sharp environmental heterogeneity.

La recolonisation des champs abandonnés par l'espèce forestière Anemone nemorosa L.: II - Rythme saisonnier, reproduction et potentialité générative des populations de forět, de broussailles et de prairie

Abstract The recolonization of abandoned fields by means of the forestal species Anemone nemorosa L.: II - Seasonality, reproduction and generative potentiality of forest, shrubs and grassland populations. - Anemone nemorosa as pioneer of the forest recreation on oldfields was investigated in permanent study areas on the Bialowieza Primeval Forest and Bialowieza clearing (Poland). Studies on seasonality, seeds production and generative reproduction potentiality were carried out. Considerable differences were found between three population of Anemone nemorosa (in Tilio-Carpinetum forest, shrubs and grassland) showing, in spite of reaction to the exceptional climate, a bigger role of generative reproduction as normal characteristic for the individuals in pioneer conditions.

Data quality in field surveys: methods and results for tree condition, phenology, growth, plant diversity and foliar injury due to ozone

Abstract Vegetation-related response variables adopted in the ICP Forests are related to health, growth, phenology, and diversity. Their assessment and measurement is subject to errors, which need to be controlled and documented. To do this, data quality requirements (DQRs) and intercomparison exercises were implemented. During 2009 and 2010, 111–260 field crews took part in different exercises organized across Europe. Results revealed that, while for some variables (e.g., tree diameter, standing basal area, ozone injury, species diversity) DQRs were substantially achieved, problems still exist for other measurements/calculations (tree height, volume and increment, crown base height, crown symptoms identification and description). In some cases, achievement of DRQs was partly due to relaxed DQRs. While the recent progresses in Quality Assurance/Quality Control for field surveys are promising, further effort is necessary to sharpen DQRs, refine standard operating procedures, and reinforce training.

Unravelling mechanisms of short-term vegetation dynamics in complex coppice forest systems

The silvicultural management of coppicing has been very common in deciduous forests in many European countries. After decades of decline of this practice, socio-economic changes might induce a revival valuing the biomass as a resource. New insights in the ecological processes that regulate plant diversity are relevant for a sustainable forest management. While studies on long-term changes are available, the short-term dynamics of the coppice forest understorey has not yet been explored. In this context, it is interesting to evaluate the species compositional changes, including the processes of species turnover and species impoverishment (nestedness) and to investigate the role of plant functional traits. For this purpose, we resampled a chronosequence of complex coppice beech forests of the Central Apennines (Italy) monitoring the short-time species dynamics of five years (i.e. from 2006 to 2011) in three age classes, i.e. post-logged, recovering and old coppice stands (0–16, 17–31 and > 32 years, respectively). In contrast to our expectation, declining species richness appeared only in the recovering stands, while the landscape scale (between-stand) heterogeneity, except for post-logged and recovering stands in 2011, did not change over five years. Significant temporal nestedness was found in each stage of succession. However, the rate of species turnover and species impoverishment do not significantly differ among the three age classes, indicating their constant importance along the forest regeneration after disturbance. Only in the early stage of forest regeneration after coppicing, species compositional changes are reflected by functional changes with surviving understorey species having clonal regeneration traits. Our results suggest an overall landscape-scale stability (and sustainability) of this coppice forest system. We conclude with management indications, highlighting the importance of maintaining the traditional local approach (coppicing with standards in small 0.5–1.0 ha sized management units with a ca 30-year rotation cycle) where active coppice parcels are interspersed by abandoned stands.

Clonal Growth Modes in Plant Communities Along a Stress Gradient in the Central Apennines, Italy

A simplification from species to functional groups using the concept of clonality is particularly attractive for predictive modelling of vegetation processes and preparing guidelines for nature conservation. This important functional trait based on a modular structure including resource-acquiring units (ramets, feeding sites) and spacers, has been studied in three plant communities (xeric grassland, mesic grassland, and beech forest) under different levels of environmental stress (related to soil moisture and fertility) in the Montagna di Torricchio Nature Reserve near Camerino, Central Apennines, Italy. The study sought to reveal patterns of clonal growth modes (CGMs) in the three plant community types, and to test a series of hypotheses on the importance of selected CGMs along the stress gradient. Clonality was shown to have different importance in the grassland communities, due to differences in the importance of various CGMs (representing syndromes of clonal traits). Below-ground positioning of CGOs, shorter spacers, higher multiplication potential, permanent physical connection between ramets, large bud bank, and increased importance of bud protection were frequently found in water-stressed xeric grasslands, suggesting the adaptive value of these clonal traits. The major differences between grassland communities were due to the dominant CGMs: turf graminoids (with an effective way of protecting growth meristems in dense tussocks) dominated xeric grasslands, whereas rhizomatous graminoids (typical of competitive resource-rich habitats) dominated mesic grasslands. The beech forest had fewer clonal species (67%) and lower CGM diversity. Based on the assumption that different environments promote different selection pressures, the tests revealed the following results: (1) Plants with clonal organs below ground have significantly higher cover values in stressed habitats. (2) Species with short spacers are more frequent in less favourable environments, and their importance is almost ten times higher in the xeric grassland than in the forest (71% to 7.6%). (3) The number of species able to produce numerous ramets is highest in the most stressed habitat. (4) The number of species with a potential for longlasting connection between ramets increases towards stressed environments. In contrast to our expectations, the mesic grasslands (occupying the central position along the studied stress gradient) have the highest number of species with storage organs. (6) In stressed habitats, species with forms of bud protection were the most frequent.

Plants and the Problem of the Individual

The biological and structural nature of plants is such that definition and operative recognition of individuality are particularly problematic. Often the term “individual” is used vaguely, and it is necessary to be more specific, when considering various biological and taxonomical entities, plant phenomena and structures of various ranks, as well the course of ontogeny or various populations.