Made available in DSpace on 2015-09-25T12:18:47Z (GMT). No. of bitstreams: 1 Adriano Melo Cordeiro.pdf: 664397 bytes, checksum: 926925fba89f26cb339b352bd63a1016 (MD5) Previous issue date: 2011-07-28 / The biodiversity hotspots altitudinal gradients in Brazil is little studied. On Northeast of Brazil and especially in the many semiarid mountainous areas are found and apparently function as refuges for the vegetation of the Caatinga present themselves as obstacles to the natural anthropogenic. The need to evaluate phytodiversity contained in the two fragments of vegetation found in the hills of Fontainha (7°28'74'' S and 36º23'47'') in Cabaceiras and mountain Bonita (07°44'42"S and 36°02'56") in Alcantil through its quantification as well as understand the structural organization of plant communities, due to altitudinal variations became the objective of this work. The study took place between November 2010 to May 2011, to sample the plant community in the mountains, was adopted the method of point-and-quadrant. In each saw 30 sampling units were chosen (Transects) each unit divided into six points, which are distant from each other 10m. The transects were distributed to separate altitudinal gradients. In all points were measured diameter at ground level and height, being the inclusion criteria for individuals to height (h) ≥ 1 m diameter at the soil (DNS) ≥ 3 cm. For the hierarchical classification of taxon was used Angiosperm Phylogeny Group II system (APG II, 2003). For analysis of the composition floristic and phytosociological parameters we used the software Mata Nativa (CIENTEC, 2002). The data were analyzed to allow comparison of composition and structure between the gradients of the same hill as well as between the same gradient of different saws. The families most conspicuous in both areas were Euphorbiaceae and Fabaceae. In mountain Bonita and Fontainha showed the greatest importance value was Croton blanchetianus fact that shows the success ecology of the species characterized by its high frequency in the sampling units. The other species with the most obvious values for the parameters phytosociological were Poincianella pyramidalis, Mimosa sp. Aspidosperma pyrifolium, stipulaceae Piptadenia and Mimosa hostilis, species typical of these degraded areas. There were differences in diversity and structure of vegetation in relation to altitudinal gradients, and the areas top the most conserved in this study. Thus, for the study area the vegetation in mountain ranges not necessarily the best preserved in semiarid, as the parameters evaluated here showed, these fragments of mountain range, with a richness and vegetation low diversity compared with other fragments of scrub and there influence of altitude on the composition and diversity of these mountainous areas. / A biodiversidade de áreas em gradientes altitudinais no Brasil é pouco estudada. No Nordeste do Brasil e especialmente na região semiárida muitas áreas serranas são encontradas e aparentemente funcionam como refúgios à vegetação de Caatinga por apresentarem-se como obstáculos naturais ao antropismo. A necessidade de se avaliar a fitodiversidade contida em dois fragmentos de vegetação encontrados na serra da Fontainha (7°28'74 S e 36º23'47 ) em Cabaceiras e na Serra Bonita (07°44′42″S e 36°02′56″) em Alcantil por meio de sua quantificação, bem como compreender a organização estrutural das comunidades vegetais, face às variações altitudinais tornou-se o objetivo deste trabalho. O estudo ocorreu no período de novembro de 2010 a maio de 2011. Para amostragem da comunidade vegetal nas serras, foi adotado o método do ponto-e-quadrante. Em cada serra foram escolhidas 30 unidades amostrais (transectos), cada unidade dividida em 6 pontos, os quais distavam 10m entre si. Os transectos foram distribuídos de forma a separar os gradientes altitudinais. Em todos os pontos foram aferidos o diâmetro ao nível do solo e a altura total, sendo o critèrio de inclusão os indivíduos a Altura (h) ≥1 m e o diãmetro ao nível do solo (DNS) ≥ 3 cm. Para a classificação hierárquica dos táxons foi utilizado o sistema Angiosperm Phylogeny Group II (APG II, 2003). Para análise da composição florística e dos parâmetros fitossociológicos foi utilizado o software Mata Nativa (CIENTEC, 2002). Os dados foram analisados de modo a permitir a comparação da composição e estrutura entre os gradientes de uma mesma serra, bem como entre o mesmo gradiente de serras distintas. As famílias mais conspícuas em ambas as áreas foram Euphorbiaceae e Fabaceae. Na Serra Fontainha e Bonita, a espécie com maior valor de importância foi Croton blanchetianus, fato que evidencia o sucesso ecológico da espécie caracterizada pela sua alta frequência nas unidades amostrais. As demais espécies com os mais evidentes valores para os parâmetros fitossociológicos foram Poincianella pyramidalis, Mimosa sp. Aspidosperma pyrifolium, Piptadenia stipulaceae e Mimosa hostilis, espécies estas típicas de áreas mais degradadas. Houve diferenças na diversidade e estrutura da vegetação em relação aos gradientes altitudinais, sendo as áreas de topo as mais conservadas neste estudo. Assim, para área estudada a vegetação de caatinga em serras não necessariamente é a mais conservada no semiárido, pois os parâmetros aqui avaliados evidenciaram, nesses fragmentos serranos, uma vegetação com riqueza florística e diversidade baixas, quando comparadas a outros fragmentos de caatinga e que há influência da altitude na composição e diversidade dessas áreas serranas.

Natürliche Standorte der Waldkiefer gibt es in Deutschland nur kleinflächig. Während Kiefernforste anstelle natürlicher Laubwälder heute oft landschaftsprägend sind, bildet die konkurrenzschwache und lichtbedürftige Kiefer ausschließlich auf extrem trockenen oder nassen, nährstoffarmen Standorten naturnahe Schlusswaldgesellschaften. Regionale Schwerpunkte liegen in subkontinentalen Regionen wie dem nordostdeutschen Tiefland und Bayern, ein „natürliches Kiefernareal" lässt sich aber kaum abgrenzen. An der Trockengrenze des Waldes finden sich auf Kalk- und Dolomitgesteinen artenreiche Karbonat-Trockenkiefernwälder mit Elementen der alpinen Rasen und Kalkmagerrasen in der Bodenvegetation. Diese Wälder besiedeln steile, südexponierte Felsen und morphodynamisch aktive Bereiche wie Rutschhänge und FlussSchotterböden im Umkreis der Alpen, kommen aber auch in den Mittelgebirgen vor. Ihr Gegenstück auf sauren Standorten sind die Sand- und Silikat-Kiefernwälder der Quarzsande und Sandstein-Verwitterungsböden, deren Bodenvegetation durch Zwergsträucher, Moose und Strauchflechten geprägt ist. Hier siedelt die Kiefer in den Tieflagen besonders auf Binnendünen und Sandern, aber auch auf Küstendünen der Ostsee, in den Mittelgebirgen z. B. auf den Sandsteinriffen der Sächsischen Schweiz. Der dritte Wuchsbereich natürlicher Kiefernwälder sind saure, nährstoffarme Moore, die ganz überwiegend von Regenwasser gespeist werden. Auch die Kiefern-Moorwälder sind in Nordostdeutschland und Bayern am häufigsten. Von diesen Standorten ausgehend, wo ihr Platz kaum von anderen Baumarten streitig gemacht wird, tritt die Waldkiefer immer wieder als Pionier auf weniger extremen Standorten auf. In der Naturlandschaft kam dies etwa nach Waldbränden oder Stürmen vor, doch der Mensch förderte die Kiefer durch Auflichtung der Wälder, Waldweide und Streunutzung stark. Auch die damit verbundene Nährstoffverarmung macht eine exakte Abgrenzung natürlicher Kiefernstandorte unmöglich. Die schlechtwüchsigen und forstwirtschaftlich nicht interessanten, ästhetisch aber sehr ansprechenden natürlichen Kiefernbestände sind heute vor allem durch Stickstoff-Immissionen gefährdet. Trotz ihrer oft kargen Erscheinung besitzen sie einen hohen Wert für die Biodiversität und den Artenschutz. Neben bodenbewohnenden Flechten und regionalen Relikt-Endemiten ist vor allem die in den letzten Jahrzehnten zunehmend gefährdete Vielfalt an Mykorrhiza-Pilzen hervorzuheben, die der Kiefer das Leben auf extrem nährstoffarmen Standorten überhaupt ermöglichen. Abschließend werden mögliche Schutz- bzw. Regenerationsmaßnahmen wie das Abplaggen flechtenreicher Kiefernstandorte vorgestellt. / Only small areas of natural Scots pine (Pinus sylvestris) habitat occur in Germany. Today pine plantations instead of natural deciduous forests often dominate the landscape. Yet, due to the competitive weakness and light demands of Scots pine, near-natural Scots pine climax communities are only found on extremely dry or wet, nutrient-poor sites, primarily in subcontinental regions of the north-eastern German lowlands and Bavaria. However, the "natural distribution range" of Scots pine is difficult to define. Species-rich, dry Scots pine forests, with alpine and calcareous grassland species in the ground vegetation, are found at the aridity limit of forests on sites with carbonate rich soils developed from limestone and dolomite parent material. These forests occur on steep south-facing slopes, on morphodynamically active areas such as landslides and coarse river gravel beds in and near the Alps, and also in the low mountain ranges. Scots pine forests are also found on acidic sites, on quartz sands and soils overlying weathered silicate rocks with an understorey dominated by dwarf shrubs, bryophytes and fruticose lichens. These forests are present in the lowlands, particularly on inland dunes and glacifluvial deposits, but also on coastal dunes around the Baltic Sea and in the low mountain ranges, for example on the sandstone cliffs in the Elbe Sandstone Mountains. Acidic, oligo-trophic bogs, mainly supplied by rainwater, comprise the third natural Scots pine forest habitat. These Scots pine bog forests occur most frequently in north-eastern Germany and in Bavaria. Coming from these habitats, where virtually no other tree species grows, Scots pine is found again and again as a pioneer on less extreme sites. In the natural landscape, it occurs mainly after forest fires and storms. Yet humans promote Scots pine by thinning forests, creating woodland pasture and removing litter. The nutrient depletion associated with these practices makes an exact delimitation of natural Scots pine habitats unfeasible. Natural pine forest stands, which, although attractive and appealing, grow poorly and are of little interest for forestry, are endangered mainly by anthropo-genic nitrogen depositions. Despite their meagre appearance, these forests are important for biodiversity and species conservation. In addition to terricolous lichens and regional relic endemic plant species, the diversity of mycorrhiza fungi, which enable Scots pine to exist on these nutrient-poor sites, increasingly is becoming endangered. Finally, possible conservation and regeneration practices, such as manually cutting sods in lichen-rich Scots pine forests, are presented.

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