CHLORISTIC DIVERSITY: THE CASE OF THE MOUNTAINOUS ECOSYSTEM OF PARNIS GREECE

Transcription

1 Proceedings of the 9 th International Conference on Environmental Science and Technology Rhodes island, Greece, 1 3 September 2005 CHLORISTIC DIVERSITY: THE CASE OF THE MOUNTAINOUS ECOSYSTEM OF PARNIS GREECE S. KOLLAROU 1 1 Department of Home Economics and Ecology, Harokopio University 41, Paraskevopoulou str., GR Athens, Greece skollarou@yahoo.gr EXTENDED ABSTRACT Parnis is the highest (1.413 m) and the bigger ( ha) mountain of Attica and it is located 40 Km north of Athens. Even though Parnis is a well-studied mountain by different scientific sectors, it has never been realized a complete chloristic and phytosociological research for this mountain. The aim of the present paper is to present plant diversity of the mountains Parnis National Park, and to prove how diversity and chloristic composition are altered through the alteration of the altitude, the vegetation structure and the ecotype. In the frame of the research, 22 plots were selected from which 239 taxa were collected. Chloristic research is constituted firstly to the analysis of the life forms and to the life-form spectrum of the total flora and secondly, to the chorological analysis and to the chorological spectrum. In addition, a number of comparisons between chloristic data from various references was done, which proved firstly the existence of new chloristic references in the study area and secondly the importance of the flora in the study area and in the mountainous ecosystem of Parnis, in general. After this, the phytosociological research was done according to data collected in the field, during the collection of the taxa, concerning altitude, inclination, formation and percentage of vegetation coverage. To put data in order, plant species classification methods were used so as to classify into clusters the plots with a relevant species composition. The methods used were the Detrended Correspondence Analysis (DCA), the Canonical Correspondence Analysis (CCA) and the cluster analysis. The description of the relationship between the number of taxa and the factors of the plots was done through the Principal Component Analysis (PCA). More regressions or correlations were also done for the measurement and the description of the kind of the relationship between two factors and for indicate the presence or not of a statistical relationship between them. Overall, the mountainous ecosystem of Parnis has great chloristic diversity and it is rich in endemics and rare species. Grasslands and open spaces present high ecological value as they have the bigger chloristic richness and the higher mountainous areas and the rock formations present a great proportion of endemics and rare species. The factor that plays the most important role in relation to the chloristic richness per plot is altitude and secondly inclination. Conclusively, the study area is a remarkable site of Southern Greece with a noticeable ecological and chloristic value. Key words: Chloristic diversity, phytosociological research, ecotype, species richness Β-412

2 1. INTRODUCTION In this paper, a thorough study of the chloristic composition of the vegetation units of the selected study area is being done because the knowledge of the chloristic composition drives to the detailed description of the qualitative alteration of the plant life forms of an ecosystem and because composition on a plant taxa level constitutes the most important indices of chloristic diversity. Chloristic richness of the study area is of a great importance too as it constitutes one of the most important and most used, due to the national bibliography, indices of chloristic diversity [1], [2], [3]. The present paper is a part of a post graduated thesis and that s why plant collections and fieldwork were done in the limited time of one year. The goals of this study are 1) the record of the taxa that are met in the area of the Parnis National Park core, 2) the comparison of the collected taxa with the chloristic catalogues that already exist in the Greek and foreign bibliography for Mount Parnis and 3) the phytosociological analysis and the composition of the vegetation units mainly by altitude change with the use of statistical methods and computer software. 2. MATERIAL AND METHODS 2.1. Study site As a study area it was chosen the Mount Parnis, which is one of the older National Parks of Greece (foundation year 1961). Given the severe restricted measures that are applied in National Parks it is of a great interest to see how chloristic diversity is being changed and what is the ecological value in an area where human intervention is supposed to be limited. On Parnis, there are three vegetation zones: of evergreen broadleaves, of Pinus halepensis and of Abies cephalonica. There are also grasslands and rock formations. As for the bio-climate, the low altitude sites belong to the semi-dry bio-climatic level with soft winter and the higher sites to the humid bio-climatic level with cold winter Sampling design On the whole, 22 samplings (plant sample collections) were conducted based on: 1) altitude, 2) vegetation structure (closed-sparse clusters) and 3) ecotype (forests, grasslands, rocks, etc). For every plot it was filled a report in which all ecological data were included for each sampling as well as other useful information such as size of plots (m 2 ), altitude (m), inclination, slope, formation, physiognomic discernible ecotype, geological bedding, land capacity units, grade of coverage of the main vegetation levels etc. Before the selection of the plots, a recognizing research of the study area was conducted for determine vegetation forms with the help of 1991 s aerial photographs of the area on which someone can see the main forest types, the percentage of crown coverage (%) and the bulk classes (m 3 ). After the selection of the exact sites, the sampling plots were chosen using the desirable shape and surface (square, 50m 2 for the woody closed clusters and 100m 2 for the sparse clusters) with the use of a metre. The geographical coordinates of each plot were defined with the use of GPS. Altitude and slope were determined with GPS too and inclination by using a simple clinometer. Finally, the grade Β-413

3 of coverage of the main vegetation levels and the ecotype were determined after observations on the spot Data collection Plots were located in the field between May and June Each plot was visited a second time after the middle June for the collection of some species, later flowering. The visitation to and the sample collection by different and representative biotopes with many different vegetation types in different altitudes were of a special concern. The identification and the classification of the taxa were done in the Forest Ecology lab of the Institute of Mediterranean Forest Ecosystems & Technology of Forest Products. For the terminology it was followed Flora Europaea [4], Mountain Flora of Greece Ι and ΙΙ [5], [6] and Med-Checklist [7]. 3. CHLORISTIC RESULTS 239 plant taxa were collected in the study area (gymnospermous 2,09%, dicotyledonous 78,24% and monocotyledonous 19,67%). Inside these are included 66 new chloristic references in relation to the only completed and more famous chloristic catalogue for Mount Parnis, this of Dr. Diapoulis (1960) Analysis of the life forms life-form spectrum The analysis of the study areas flora showed that different life forms take part on the entire flora with these percentages: Therophytes (T) 38,91%, Hemicryptophytes (H) 29,71%, Chamaiphytes (Ch) 10,88%, Phanerophytes (P) 10,46%, Geophytes (G) 9,62% and taxa with non completely defined life form 0,42%. The life-form spectrum of the study area is the presentation of these percentages graphically Chorological analysis chorological spectrum Chorological data are classified based on the center of their geographical origin, from which, with natural ways, they spread to different directions [8]. For the chorological analysis, 237 taxa were taken into account, as there are 2 taxa with unknown geographical spreading. There are also 10 taxa (4,22 %) that they take part in the analysis of the chorological spectrum for which only the family is identified, because either of their early collection or of their bad drying, so it was impossible to determine their chorological type. These species of course are not the same with others of the same family that may have been collected. The numeric and the percentage proportion of the ground elements of each unit compose the chorological spectrum of the flora of the study area Chloristic evaluation In the frame of this research many comparisons between the collected taxa and the already existed Greek and foreign chloristic catalogs for the Mount Parnis were done. The resulted conclusions are summarized below: 2,93% of Mount Parnis plant taxa is Greek endemics [9], [10]. From the collected taxa, four (4) are Greek endemics (1,67% of the total). From the total number of Mount Parnis plant taxa, 15,89% is sprouted mainly in altitudes higher than meters [6], [9]. Β-414

4 The most of the endemics taxa of Attica and Central Greece are met on Parnis [6], [11]. 4. PHYTOSOCIOLOGICAL RESEARCH 4.1. Method Two logistic packages were used for the statistical analysis of the data that came up from chloristic research; these are PC-ORD (version 4) and Stat-Graphics Plus 4. The factors used for the above analysis are altitude, formation, coverage percentage of the main vegetation levels and inclination. The working out of the plant taxa was done in the level of presence-absence and not by their coverage percentage Results Detrended Correspondence Analysis (DCA) Detrended Correspondence Analysis combines plots and biological data through mathematic axes in the frame of the similarities and differences of taxa composition. This method clustered plots in six divided groups: 1) hays, 2) plots with intense human presence and intervention, 3) woody closed clusters and sparse clusters of conifers or plots near conifers, 4) fir open spaces, 5) rocks with grasses and 6) rock formations Principal Component Analysis (PCA) Principal component analysis was chosen for the determination and the description of the relations between number of taxa and the above mentioned selected factors. According to this analysis, plots are separated in six new groups, with some similarities in relation to the previous ones. Those are: 1) sparse conifer forests or plots near conifer clusters, 2) plots with intense human presence and intervention, 3) plots with hays, 4) sparse fir forests, 5) closed conifer forests, and 6) rocks. This method also showed that the factor that plays the biggest role concerning chloristic richness per plot is altitude (based on the plot of component weights) Canonical Correspondence Analysis (CCA) Canonical Correspondence Analysis (CCA) is a direct component technique, which comprises correlations and regressions between chloristic data and environmental factors during ordination analysis and it is used for exploring the relationships between chloristic composition of each plot and different selected environmental factors [12], [13], [14]. The produced ordination graphics show the correlation of the taxa or of the plots with the environmental factors. The best grouping of plots was done in the followed (fig. 1) diagram (axes 1-3) that shows that there is a clear altitudinal graduation of the plant taxa expansion. The total cumulative % explained by those axes is 13,4%, which is quite small. That percentage could be bigger with the use of a more expanded net of sampling plots per zone of altitude and with the choice of plots of a bigger surface (e.g m 2 ) inside of which, the total number of plant taxa could be recorded in vertical and horizontal level for three years minimum. These conditions were unable to be realized, as this paper is a part of a postgraduate thesis of limited time. Β-415

5 Canonical Correspondence Analysis showed that altitude was the factor the most determined for the ordination of the sample plots. CCA Form Ax is Alt. 10 Incl Figure 1: Plot classification with CCA technique in a two-axis system Cluster Analysis The classification technique used is the Ward method (1963) or else Minimum variance of square clustering. The dendrogram created by this method drove to the classification of plots in five clusters. These are: 1) clusters of fir, 2) clusters of pines, 3) clusters of other conifers, 4) rock formations and 5) plots with intense human intervention (fires, reforestation, apiculture). After the explanation of the above results, it is concluded that there is a relationship between the groups of plots as they are finally formed. In general lines, chloristic diversity of the study area is altered with altitude, as CCA demonstrated and with vegetation structure, as all the other analysis showed. The main structures met in the study area which seems to be responsible for the determination of the plant diversity are: Rocks, Grasslands Hays, Fir forests, Pines forests, Conifer mixed forests, Areas with intense human presence and intervention Regressions correlations Axis 1 For the completion of the phytosociological research, a multiple regression analysis was done that, after a number of steps, it finally gave a simplified model which explains the relation between the number of taxa and the main parameters that are two, altitude and inclination. This simplified equation is: Taxa = *Altitude-5.481*Inclination where R 2 = % and a 95%. Simple regressions showed that [importance level (a) 90%]: Β-416

6 The most plots with many taxa (>30 taxa) are either in very low (<500 m) or in relatively high (1.000 m) altitudes. Altitude is the factor that explains the variation of the number of taxa in a percentage of 14,9973 %. The most plant taxa appear in plots of small inclination (0-10%). Inclination is the factor that explains the variation of the number of taxa in a percentage of 24,5369 %. The plots with the most plant taxa are met in sparse and extremely sparse clusters, with percentage of the main levels of coverage at 25-50% and 0-10% respectively. Coverage of vegetation is the factor that explains the variation of the number of taxa in a percentage of 0,7234 %. Formation is a quality factor and for that reason it was correlated to the number of taxa with the Χ 2 method, in order to find the kind of relationship between those two parameters. The results showed that the two factors are independent (the number of taxa may have no relation to formation in a specific case) and that the most taxa are met in complex herbaceous and low woody formations, in complex herbaceous and woody high and low formations and in herbaceous formations. The combination of the results of the chloristic and the phytosociological research shows really clearly that the most interesting taxa (those are the endemics and the rare ones) are met on rocks or rock formations and in very high altitudes. 5. CONCLUSIONS The mountainous ecosystem of Parnis has great chloristic diversity and it is rich in endemics and rare species. Grasslands and open spaces present high ecological value as they have the bigger chloristic richness and the higher mountainous areas and the rock formations present a great proportion of endemics and rare species. The factor that plays the most important role in relation to the chloristic richness per plot is altitude and secondly inclination. Conclusively, the study area is a remarkable site of Southern Greece with a noticeable ecological and chloristic value. REFERENCES 1. Magurran A.E. (1988) Ecological Diversity and its Measurement, Chapman and Hall, London. 2. Hellmann J.J. and Fowler G.W. (1999) Bias, precision, and accuracy of four measures of species richness, Ecology, 9, pp Battles J.G, Shlisky A.G., Berrett R.H., Heald R.C. and Allen-Diaz B.H. (2001) The effects of forest management in a Sierran conifer forest, Forest Ecology and Management, 146, pp Tutin T.G. et al. (Eds) ( ) Flora Europaea, 1-5, Cambridge University Press. 5. Strid A. (ed.) (1986) Mountain Flora of Greece, Vol. I, Cambridge University Press. 6. Strid A. and Tan (Eds) (1991) Mountain Flora of Greece, Vol. II, Edinburgh University Press. 7. Greuter W., Burdet H.M. and Long G. ( ) Med-Checklist, Vol. 1, 3, 4, Geneva. 8. Pignatti S. (Ed.) (1982) Flora d Italia, Vol.1-3, Bologna. 9. Diapoulis Ch.A. (1960) From the flora of Parnitha, Study. 10. Georgiou K. (2001) CHLORIS Data Base. 11. Hallmann B. and Sfikas G. (1994) CORINE Data Base. 12. Odland A., Birks H.J.B. and Line J.M. (1990) Quantitive vegetation-environment relationships in west Norwegian tall-fern vegetation, Nord. J. Bot., 10, pp Oglethorpe D.R. and Sanderson R. (1998) Farm characteristics and the vegetative diversity of grasslands in the North of England: a policy perspective, Biodiversity and Conservation, 7, pp Stohlgren T.J., Owen A.G. and Lee M. (2000) Monitoring shifts in plant diversity in response to climate change: a method for landscapes, Biodiversity and Conservation, 9, pp Β-417