The classification of the plant communities with variables the four nature conservation criteria, i.e. diversity, naturalness, rarity and restorability identified three community groups (Table 4.20 & Fig.4.14). The 1st community group was characterized by high naturalness and restorability value and medium to low diversity and rarity value. The group included three forest communities with Quercus
pubescens (communities 12, 14 and 22) and the two communities of Acer obtusatum
(communities 23 and 24). Platanus orientalis and Asperula chlorantha communities, which had been excluded from the classification, due to incomplete diversity data, were subjectively included in the 1st community group. The high naturalness and restorability value of these communities suggested their inclusion to this community group. The ecological value of the communities of the 1st group is related to their high naturalness and restorability value, attributes which should be safeguarded and thus direct their future management.
The 3rd community group was consisted of the shrubland communities of Phlomis
fruticosa (Phl_fr8), Salvia officinalis (Sal_of9) and Juniperus oxycedrus (Ju_ox10)
and five grassland communities. These communities were characterized by high diversity, medium to high rarity, medium restorability and medium to low naturalness. The nature conservation value of these communities is related to their high plant species diversity and rarity, characteristics that can be preserved through an active management that favors the traditional land uses such as extensive grazing.
The 2nd community group aggregated communities exhibiting low to medium values for all four nature conservation criteria. The forest pasture of Quercus pubescens (Ju_Qpu13), the tree hedges (Ru_Qpu18), the woodlands of Quercus coccifera (Q_coc11) and Carpinus orientalis (Car_or21), the forest fringes of Parietaria
officinalis (Par_of16) and Pteridium aquilinum (Pte_aq19), the meadows of Trifolium
nigrescens (Tri_ni3) and the nitrophilous community of Marrubium peregrinum
(Mar_pe4). These plant communities can be subject to a flexible land management scheme and can either provide for traditional land uses, or be set aside for nature conservation or future use.
H I E R A R C H I C A L C L U S T E R A N A L Y S I S Dendrogram using Ward Method
Rescaled Distance Cluster Combine
C A S E 0 5 10 15 20 25 Label Num +---+---+---+---+---+ Be_per1 18 òø Poa_bu5 21 òôòòòòòø Hel_nu6 16 ò÷ ó Jas_fr7 15 òø ùòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòòø Di_vis2 19 òôòø ó ó Phl_fr8 13 ò÷ ùòòò÷ ó Ju_ox10 11 òûò÷ ó Sal_of9 12 ò÷ ó Qp_Car22 4 òûòø ó Co_Qpu14 6 ò÷ ùòø ó Ac_Ost24 2 òûò÷ ùòòòòòòòòòòòòòòòòòòòø ó J_Aobt23 3 ò÷ ó ó ó Qpub12 5 òòòòò÷ ó ó Ru_Qpu18 8 òø ùòòòòòòòòòòòòòòòòòòòòòòò÷ Q_coc11 9 òôòø ó Ju_Qpu13 7 ò÷ ùòòòø ó Car_or21 10 òòò÷ ùòòòòòòòòòòòòòòòòò÷ Tri_ni3 17 òûòø ó Mar_pe4 20 ò÷ ùòòò÷ Pte_aq19 23 òûò÷ Par_of16 24 ò÷
Fig.4.14 Dendrogram of the plant communities resulted from hierarchical classification with variables the four nature conservation criteria, i.e. diversity, naturalness, rarity and restorability. The communities were clustered in groups of similar pattern in the four criteria. The group 1 incorporated the communities characterized by high naturalness, the group 3 aggregated those characterized by high diversity and the group 2 contained the communities with medium values of the criteria.
The Principal Component Analysis (PCA) of the four nature conservation criteria of the communities identified two components that explained 86% of the total variance in the dataset. The component matrix (Tables 9 & 10 in Annex) revealed the association (correlation) between the nature conservation criteria and the two components. The PCA axis 1 was positively correlated with the criteria of naturalness and restorability, while the axis 2 was positively correlated with diversity and rarity (Fig.4.15). By plotting the PCA scores of the communities along with the classification results, the characteristics of the three community groups were demonstrated.
Group 2 Group 1 Group3
Table 4.20 Overall ecological evaluation of the plant communities Plant
community Vegatation type Naturalness value Restorability value Diversity value Rarity value Community group
Qpub12 F High High Medium High
Qp_Car22 F High High Medium Medium
Co_Qpu14 F High High Medium Low
Ac_Ost24 F High High Low Medium J_Aobt23 F High High Low Low
1
Ju_Qpu13 F Medium Medium Medium Medium
Ru_Qpu18 F Medium Medium Medium Medium
Q_coc11 W Medium Medium Medium Medium
Car_or21 W Medium Medium Low Medium
Pte_aq19 G Medium Medium Medium Low
Par_of16 G Medium Low Medium Low
Tri_ni3 G Low Low Medium Low
Mar_pe4 G Low Low Medium Low
2
Ju_ox10 S Medium Medium High High
Sal_of9 S Medium Medium High High
Phl_fr8 S Low Medium High High
Di_vis2 G Low Medium High High
Jas_fr7 G Low Medium High High
Be_per1 G Low Medium High Medium
Poa_bu5 G Low Medium High Medium
Hel_nu6 G Low Medium High Medium
3
Pla_or15 F High High - Low Asp_ch17 G High High - Low
Br_syl20 G Medium Medium - Medium
*
• omitted from the classification
The bold characters in a specific plant community group indicate the criterion(-ria) that should direct the management of the specific communities.
The application of the same classification procedure twice more, once by giving weight to the criterion of naturalness (1st scenario: supporting the naturalness) and once to diversity (2nd scenario: enhancing the plant species diversity), resulted to the same groupings with the initial analysis that was applied with no weight to any of the criteria. This was considered to validate the results of the applied evaluation scheme.
Fig.4.15 Scatter plot of the factor scores of the plant communities, resulted from Principal Component Analysis (PCA) of the community matrix with the four nature conservation criteria, i.e. naturalness, restorability, diversity and rarity. The 1st PCA factor is positively correlated to naturalness and restorability. The 2nd PCA factor is positively correlated to diversity and rarity. The hierarchical classification of the plant communities with variables the four nature conservation criteria resulted in three community groups that were superimposed at the scatter plot. Some communities had the some position in ordination space and they were slightly moved so that to distinguish their names.
5 Discussion