Geobotanical Study of the Microforests of Juniperus oxycedrus subsp. badia in the Central and Southern Iberian Peninsula

Abstract

We have studied Juniperus oxycedrus L. subsp. badia (H.Gay) Debeaux in the central and southern Iberian Peninsula, where the macrobioclimate ranges from Mediterranean-pluviseasonal-oceanic to Mediterranean-pluviseasonal-continental, and the thermotype from the thermo- to the supramediterranean. The relevés were taken following the Braun-Blanquet phytosociological methodology. A statistical treatment was applied to establish a separation among Juniperus communities. To understand the presence of Juniperus communities in territories dominated by species in the Quercus genus, we applied Thornthwaite’s formula to calculate potential evapotranspiration. The general cluster analysis clearly distinguishes two groups of plant communities and separates the different associations in each group. All the plant communities growing on rocky crests and in extremely steep sloping areas are significantly influenced by the soil. The ombroclimatic index does not explain the presence of plant communities influenced by substrate, so we proposed a new ombroedaphoxeric index which explains the presence of Juniperus communities in territories with a thermotype between the thermo- and supramediterranean. The areas of distribution of Juniperus species are expanding due to the spread of rocky areas; this phenomenon causes an increase in edaphoxerophilous areas and a decrease in climatophilous ones. We propose four new plant associations, with updated structures and floristic compositions. Efficient conservation is possible in both the territories studied (Spain and Portugal) through the implementation of specific cross-border cooperation projects.

Political commitment and transparency as a critical factor to achieve territorial cohesion and sustainable growth. European cross‐border projects and strategies

“…What is more, this idea also corroborates with previous findings (Castanho et al, ). Those findings are in line with previous studies and researches conducted over European territories—Reitel (); Spirkova and Ivanicka (); De Sousa (); Magoulios, Sotirios, and Kydros (); ESPON (ECR2) (); LISER (); Kurowska‐Pysz (); Kurowska‐Pysz and Szczepańska‐Woszczyna (); Wróblewski, Dacko‐Pikiewicz, and Cuyler (); Liberato, Alén, Liberato, and Domínguez (); Caldés, Del Río, Lechón, & Gerbeti, ; Cano, Musserella, Cano‐Ortiz et al (); Nikologianni, Moore, and Larkham (); among many others—a need for strategic unification, as well as a deep relation of the present CBC deterioration with the 2008 economic crisis. Many of those studies highlight that the members of border institutions consider the identification of common strategic guidelines and their implementation based on concrete project actions, which constitutes a crucial step in trust building, increasing commitment and future cooperation.…”

Bioclimatology, Structure, and Conservation Perspectives of Quercus pyrenaica, Acer opalus subsp. Granatensis, and Corylus avellana Deciduous Forests on Mediterranean Bioclimate in the South-Central Part of the Iberian Peninsula

“…These species have their optimum in colder regions with mild summers and therefore with lower summer evapotranspiration (PEs) and annual evapotranspiration (PE) values [71]. This can be seen in the correlation coefficients between the abovementioned species and the bioclimatic variables PEs and PE in places or microclimates where the abundance or presence of these mesophytic species (which, for the most part, are part of E3), declines when the values of PEs and PE increase, either due to high temperatures [72] or to gaps in the vegetation [20,21]. Table 5 also shows that these taxa have a significant positive correlation with the humidity index (IH), the annual ombrothermic index (Io) and the summer ombrothermic indices: the ombrothermic index of the warmest month in the summer quarter (Ios 1 ), the warmest two months in the summer quarter (Ios 2 ), the summer quarter (Ios 3 ), and the summer quarter plus the previous month (May in the northern hemisphere) (Ios 4 ) [73].…”

“…phoenicea, which have a preference for warm bioclimates. These taxa do not grow in humid biotopes or with high values of Io or Ioe, except on sites with a steeply sloping topography or soil conditions that do not allow the use of rainwater (edaphoxerophilous) [1,4,20,76]. Tamus communis, Arbutus unedo, Daphne gnidium, Paeonia broteri, and Erica arborea are correlated to a lesser extent with these variables and show no correlations with Itc, Tmax, or Tmin gradients.…”

“…coccifera and Juniperus phoenicea subsp. phoenicea (occurrence of 5.4% and 6.3%, respectively, and average covers of 11.3% and 2.9%) complete the list of phanerophytes, which in other more xeric conditions establish plant communities with species typical of Querceta ilicis [1,20,76,78,79], accounting for 40.98% of maple woodland species (Table 7). The occurrence of both native and naturalised gymnosperms is particularly significant, and is largely due to anthropic action in the form of fires or tree felling.…”

“…Font Quer and Rothm., which is highly dependent on the microhabitat, and is much lower in open spaces than under established tree or shrub vegetation [19]. A decline in mesophytic conditions due to gaps in the vegetation increases the levels of direct evapotranspiration and leads to the establishment of plant communities composed of more xerophytic taxa [20]. It is vitally important for the regeneration and dynamics of the Corylus avellana L. formations in the southern Iberian Peninsula to conserve the subserial shrubs formed by dense closed thorn bushes that shelter many mature forest species [21].…”