Floristic Similarity Analysis Research Articles

Analysis of floristic similarity between forest remnants from the upper Paraná river floodplain, Brazil

The vegetation from the upper Parana river floodplain is a fragment of Seasonal Semideciduous Forest (SSF) that presents fields, lowlands and extensive areas of pasture along with forest formations. Aiming to accomplish analyses of floristic similarity between riparian forests remnants in this floodplain, an analysis using nine surveys was performed, four on the right bank, two on the left bank and three at an island, including tree species. Sorensen's (ISs) and Jaccard's (ISj) similarity coefficients were calculated, and a Correspondence Analysis (CA) was applied to a matrix of presence and absence of species. Thirty-seven families, 80 genera and 110 species were recorded. Among the species, 5.5% were generalist, while 29.1% were exclusive to one survey. The values of ISs and ISj ranged from 31 to 78.4%, and 31 to 64.5%, respectively. The CA grouped the surveys in the right and left banks and the island; the species with the highest positive correlation on axis 1 were the most common in the surveys on the left bank. The obtained results evidenced that floristic surveys constitute important indicatives for evaluations of the vegetation distribution in the floodplain.

Espécies de cerrado com potencial para recuperação de áreas degradadas por mineração de ouro, Paracatu-MG

Com o intuito de selecionar espécies que possam ser testadas na recuperação de áreas com alta concentração de arsênio, foram estudadas 10 áreas de Cerrado degradadas pelo garimpo de ouro em Paracatu, MG. Utilizou-se a escala de valores de cobertura e abundância de Braun-Blanquet, sendo as espécies classificadas também quanto à forma de vida de Raunkiaer. As áreas foram comparadas floristicamente pelo índice de Sørensen. Foram encontradas 197 morfoespécies lenhosas e herbáceas, das quais 102 foram identificadas em nível específico, 35 em gênero e 40 em família. Vinte morfoespécies não puderam ser identificadas. Houve grande variação quanto à riqueza florística entre as unidades amostrais (21-53 espécies), e esse fato influenciou a formação de três grupos na análise de similaridade florística. As espécies que se mostraram mais abundantes e provavelmente de maior adaptabilidade às condições ambientais foram: Axonopus marginatus, Simarouba amara, Aristida ekmaniana, Digitaria ciliaris, Stylosanthes viscosa, Andropogon bicornis, Maprounea guianensis e Sabicia brasiliensis. A forma de vida mais frequente foi fanerófito, seguida de hemicriptófito e caméfito. No espectro biológico, foi possível visualizar as diferentes estruturas das áreas estudadas, enfatizando-se a diversidade de ambientes presentes, apesar de apresentarem baixa riqueza florística.

Flora vascular y vegetación del humedal de Santa Rosa (Chancay, Lima)

The present work shows the results of flora and vegetation study made between 2007 and 2009 on Santa Rosa wetland (Chancay - Lima). The vascular flora was composed for 66 species, grouped on 57 genus and 26 families. The Poaceae (16), Cyperaceae (6) and Asteraceae (6) are the more diverse families and represent the 42% of the flora. A comparison between the principal wetlands of Lima shows that Santa Rosa has more plant species (Pantanos de Villa (65), Paraíso (26) and Medio Mundo (16)). The analysis of floristic similarity between those localities shows that Santa Rosa is more similar to Pantanos de Villa (Lima) than the other localities. Using a Correspondence Analysis (CA), it was possible to recognize just three kinds of plant communities: a) Floating aquatic plants community, b) Totoral with associated species and c) Mixed Vega. It is considered that the changes on the plant community structure and the quantity of invasive species are indicators of the anthropic impact on the area. Human impact sources were identified and agriculture is considered the most important menace of this ecosystem.

Flora arbustiva-arbórea de três áreas ribeirinhas no semiárido paraibano, Brasil

Objetivou-se no presente trabalho contribuir para o conhecimento florístico de três áreas ribeirinhas na caatinga e realizar a comparação destas com outros estudos desenvolvidos na bacia do Rio Taperoá, semiárido paraibano. O levantamento florístico foi realizado através de coletas assistemáticas no período de janeiro/2004 a junho/2006 e abrangeu as áreas ribeirinhas presentes ao longo dos riachos intermitentes do Cazuzinha (7° 26' 13" S e 36° 54' 30" W; 564-579 m de altitude), Mares (7° 31' 53" S e 36° 33' 39" W; 536-550 m de altitude) e Farias (7° 25' 33" S e 36° 29' 21" W; 454-470 m de altitude). O levantamento das três áreas registrou um total de 91 espécies, das quais 68 ocorreram na área do riacho do Cazuzinha, 62 no riacho dos Mares e 56 no riacho do Farias. As famílias com maior número de espécies e de gêneros foram Fabaceae, Euphorbiaceae e Rubiaceae. Do total de espécies registrado para as três áreas, 15 estão presentes nas listas relacionadas para matas ciliares de outros estados do Brasil, 26 são endêmicas da Caatinga e 10 foram exclusivas. Analisando a similaridade florística entre as áreas estudadas e outros cinco levantamentos, observou-se que a maior identidade florística está relacionada principalmente com a distância geográfica e às características de uso e ocupação da terra.

Species Diversity Patterns in Natural Secondary Plant Communities and Man-made Forests in a Subtropical Mountainous Karst Area, Yunnan, SW China

We quantified plant diversity patterns according to changes in species composition, floristic richness, and species diversity in various plant communities in the Shilin karst area (24°38′–24°58′N, 103°11′–103°29′E, altitude 1600–2203 m) of central Yunnan, China, in which the previous land use had been documented. Cluster analysis of floristic similarity of all the stands showed that plant species composition and diversity were primarily influenced by the legacies of land use (as coppices, pastures, and plantations). The DCA (detrended correspondence analysis) grouped 14 sampling transects into 3 plant communities, including a shrubland, a mixed deciduous and evergreen broad-leaved stand (secondary forest), and a premature semihumid evergreen broad-leaved stand (natural premature forest), along a disturbance gradient. We also analyzed Pinus plantations. While plant species diversity was particularly low in the Pinus plantation, stands developing (secondary forest) on former coppice sites were becoming increasingly similar to the natural premature forest. The results would indicate that vegetation and plant species diversity is more efficiently restored by letting degraded vegetation regrow rather than establishing plantations.

Estudio florístico de los piñonares de Pinus pincena Gordon

Se presenta un estudio de la flora de 14 comunidades con Pinus pinceana Gordon. Esta especie forma pequeños bosques aislados a lo largo de la Sierra Madre Oriental, en el norte y centro de México. Se realizó un análisis de similitud florística entre las localidades estudiadas. Se reportan 446 especies, más 4 taxa infraespecíficas adicionales, distribuidas en 247 géneros y 78 familias. De acuerdo con su composición florística, las comunidades estudiadas se pueden separar en dos conjuntos: las más norteñas, localizadas en Coahuila, Zacatecas y San Luis Potosí, y las de la región sur en Querétaro e Hidalgo. Se concluye que existen dos grupos de piñonares de P. pinceana, con base en sus diferencias florísticas y de distribución.

Geographical range size of tropical plants influences their response to anthropogenic activities

ABSTRACTBiodiversity patterns may be influenced by the species geographical range sizes, but this is rarely shown. We used a highly replicated and large‐scale study in coastal Ecuador to determine for the first time the importance of latitudinal range size of plant species in their response to land‐use activities. We examined herbaceous plant communities of five land‐use types with decreasing anthropogenic disturbance (from the most intervened rice and pasture to the less intervened managed agroforest, abandoned agroforest, and forest) in a low and a high impact human‐dominated landscape. All species were classified in four latitudinal range size quartiles, from the 25% species with the narrowest to the 25% with the widest range size. We found notable differences between patterns of total species richness and those of individual range size quartiles. Whereas total species richness was higher in more intervened land‐use types, percentages of narrow‐ranged species were significantly higher in less intervened land‐use types. In contrast, percentages of wide‐ranging species were higher in more intervened land‐use types. Hence, responses of plant species to human activities were influenced by traits that determine their range sizes. An analysis of floristic similarity between land‐use types revealed that narrow‐ranged species were mainly preserved in forest fragments, but the other land‐use types supported many unique narrow‐ranged species and therefore made an important contribution to their preservation at the landscape level. Conservation efforts should combine protection of natural habitats with strategies to maintain a diversity of low‐intensity land‐use types, looking for win‐win solutions or trade‐offs between biodiversity conservation and human welfare in human‐dominated landscapes.

Bat species diversity and distribution in three vegetation communities of Meru National Park, Kenya

AbstractDiversity and distribution of bats was determined in four vegetation types in and around Meru National Park, Kenya between September 2000 and February 2001. Bat‐habitat studies were based on plant species dominance, cover and farming activities. Bats were captured using standard mist nets (18 m long × 2 m high) erected on poles averaging 3 m. Vegetation was broadly grouped as Acacia or Combretum wooded grassland, or Acacia–Commiphora bushland and studied using the Braun‐Blanquet method. Analysis of floristic similarity showed five vegetation species assemblages in the three broad categories. Four hundred and ninety‐five bats representing eleven genera in seven families were recorded. These were Epomophorus labiatus, E. wahlbergi, Cardioderma cor, Lavia frons, Myotis welwitschii, Scotoecus hirundo, S. leucogaster, Pipistrellus kuhlii, Mops condylurus, Chaerephon bemmeleni, Mormopterus sp., Hipposideros caffer, H. commersoni, Nycteris arge and Rhinolophus landeri. This was the first record of N. arge, M. welwitschii, C. bemmeleni and a Mormopterus species in eastern Kenya. The Combretum community was most equitable (E = 0.51) with nine bat species records, while farming areas had only four. The low species richness and increased dominance of a few generalist species on farms may be indicative of different levels of disturbance.

Computer assisted floristic similarity analysis

A program for polythetic numerical evaluation of phytosociological material is described. Using Sorensen's coefficient of floristic similarity it computes the homogeneity of subjectively chosen sets of releves, the affinity of each constituent releve to the set as well as the similarity between any pair of sets. It is also able to plot a dendrogram of the hierarchic system obtained by agglomerating individual releves into complex groupings. The program is suitable for processing phytosociological data arranged in any conventional table.