André Luiz Alves de Lima

Caatinga revisited: ecology and conservation of an important seasonal dry forest.

Besides its extreme climate conditions, the Caatinga (a type of tropical seasonal forest) hosts an impressive faunal and floristic biodiversity. In the last 50 years there has been a considerable increase in the number of studies in the area. Here we aimed to present a review of these studies, focusing on four main fields: vertebrate ecology, plant ecology, human ecology, and ethnobiology. Furthermore, we identify directions for future research. We hope that the present paper will help defining actions and strategies for the conservation of the biological diversity of the Caatinga.

DINÂMICA DA VEGETAÇÃO EM UM FRAGMENTO DE MATA ATLÂNTICA NO NORDESTE DO BRASIL

To test the hypothesis that the physiognomy, structure and dynamics of woody species are influenced by the spatial gradient edge-interior, data were collected from these parameters in 2004, 2007 and 2010 in an Atlantic forest fragment. Species were sampled for the Canopy (DS), with circumference > 15 cm to 1.3 m soil and understory (SB) in circumference between ground level> 3 cm and CAP 150 m from the forest boundary), and analyzed 1,000 m² per site, divided into plots of 10 m², to measure individuals of higher class. In each plot a sub-plot of 5 m² for sampling understory was installed. Branches were collected from three adult individuals from the species to obtain the density of the wood. The number of individuals (NI), basal area (BA), mortality (TM), recruitment rate (TR), periodic annual diameter increment (IPA), loss rate (P) and gain rate (G) Area and basal turnover rates in number of individuals (TN) and basal area (TA) class tree component in the three locations showed no significant edge effect. At the edge, the understory had lower values ​​of NI and AB and higher TM than in the forest interior. Differences between the strata occur regardless of edge sealing, since young plants present in most individuals in the sample class SB, which are more sensitive than adult trees to changes caused by the creation of the edge. Rates of loss and gain of AB and AB turnover in NI and in SB presented higher values than on the DS, which points to a stratum with larger changes. In DS there were no differences in species richness among environments differs from that observed in SB. The floristic composition of the DS in environments closer to the forest limit was quite distinct from that of the interior, indicating that there has been no recovery of floristic composition. All environments SB had low similarity. The edges of the DS and SB had a higher concentration of individuals in class intervals smaller density values ​​timber. The DS has already recovered biomass, although the edge and intermediate environments have not recovered species composition late. The SB still suffers the edge effect. Possibly, the highest concentration of individuals is in class with lower density wood result on edge.

Leaf phytohormone levels and stomatal control in an evergreen woody species under semiarid environment in a Brazilian seasonally dry tropical forest

Phytohormones are essential for controlling abilities of plant species to overcome stress conditions, and influence some aspects of stomatal control, preventing excessive water loss. This study investigates the correlation between foliar phytohormones levels, water status and stomatal conductance in an evergreen woody species (Cynophalla flexuosa) throughout dry and rainy seasons, and the transition between them. We measured stomatal conductance (gs), xylem branch water potential (Ѱx), and leaf concentration of abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA) and trans-zeatin (tZ). Stomatal conductance was more sensitive to atmospheric conditions, such as VPD than to soil water balance. However, we found correlation between gs and Ѱx, suggesting that these direct water availability measures were a good proxy to explain gs in C. flexuosa. Moreover, ABA leaf concentration had no effect on gs, but ABA and tZ interaction was important to the phenological behaviour of this species. Cytokinins act in delaying leaf senescence, which is crucial to evergreen species, and it is opposite to ABA’s action. JA also showed a significant interaction to ABA, and kept high foliar level during wet season. ABA levels varied throughout the year, and its concentration itself was less important to gs than the interaction to other phytohormones, such as tZ and JA. In conclusion, although ABA did not directly affect stomatal conductance in C. flexuosa, the interaction between ABA, tZ and JA likely played a role in the regulation of stomatal behavior in this species.

Inoculation of plant-growth-promoting rhizobacteria in Myracrodruon urundeuva Allemão supports in tolerance to drought stress

ABSTRACT This study evaluated the influence of Azospirillum lipoferum on the growth of Myracroduon urundeuva (Anacardiaceae) plants under drought stress, by means of biometric, physical–chemical and biochemical parameters. The association of A. lipoferum with the roots of the plants provided increases of 30% root length, 50% root dry weight, 34% shoot dry weight and 10% soluble protein content. The inoculated plants still maintained 5% higher leaf water potential than those not inoculated and lower membrane damage. Furthermore, the inoculated plants shown less leaf fall and dark green leaves, confirmed by maintenance of the highest levels of chlorophyl a, b and total. On the other hand, superoxide dismutase activity was significantly lower in the inoculated plants, possibly due to the induction of a non-enzymatic protective feature. In this way, the inoculation of PGPR in M. urundeuva can be an alternative for the production of plants that are more tolerant to drought stress.

Dynamics of vegetation in an atlantic forest fragment in northeastern Brazil

To test the hypothesis that the physiognomy, structure and dynamics of woody species are influenced by the spatial gradient edge-interior, data were collected from these parameters in 2004, 2007 and 2010 in an Atlantic forest fragment. Species were sampled for the Canopy (DS), with circumference > 15 cm to 1.3 m 1 Engenheiro Florestal, Mestrando em Ciências Florestais pela Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, CEP 52171-900, Recife (PE), Brasil. felipe.rabelo@yahoo.com 2 Bióloga, Dra., Professora da Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, CEP 52171-900, Recife (PE), Brasil. mrodal@terra.br / anacarol@db.ufrpe.br 3 Biólogo, Dr., Professor da Unidade Acadêmica de Serra Talhada, Universidade Federal Rural de Pernambuco, Fazenda Saco, s/n, CEP 56900-000, Serra Talhada (PE), Brasil. andrelimabotanica@yahoo.com.br Recebido para publicação em 13/06/2012 e aceito em 19/06/2013

Crescimento Inicial de Espécies Ocorrentes no Semiárido Brasileiro: Biomassa, Biometria e Análise Morfogênica (Initial growth of species occurring in the Brazilian semi-arid region: biomass, biometrics and Morfogenical Analysis)

Objetivou-se analisar o crescimento inicial de seis especies de ocorrencia na caatinga Prosopis juliflora (Sw.) DC.; Anadenanthera macrocarpa (Benth.) Brenan; Poincianella pyramidalis Tul.; Piptadenia stipulacea (Benth) Ducke; Erythrina velutina Willd.; e, Enterolobium contortisiliquum (Vell.) Morong. Assim, foi conduzido um experimento em viveiro, no municipio de Serra Talhada-PE. As sementes foram submetidas a tratamentos pre-germinativos. Cada especie constituiu um tratamento, dispostas em delineamento inteiramente casualizado. A reposicao de agua foi feita com base na evapotranspiracao prevista para o periodo experimental. Aos 23, 37, 51, 65, 92 e 120 dias apos a semeadura foram feitas amostragens para se determinar a biomassa seca das plantas, bem como de suas partes, folhas, caule e raizes e parâmetros biometricos. Com os valores de biomassa seca e indice de area foliar foram determinados os seguintes indices morfofisiologicos: taxa de crescimento absoluto, taxa de crescimento relativo, area foliar especifica, razao de area foliar, razao de massa foliar. Tamboril e Algaroba foram aquelas que apresentaram melhores respostas biometricas e de acumulo de biomassa, em decorrencia dos seus desempenhos morfofisiologicos. Por sua vez, Angico Vermelho apresentou o menor crescimento inicial quando comparado com as demais especies. A B S T R A C T The aimed to analyze the initial growth of six species of occurrence in the ‘caatinga’ vegetation, Prosopis juliflora (Sw.) DC.; Anadenanthera macrocarpa (Benth.) Brenan; Poincianella pyramidalis Tul.; Piptadenia stipulacea (Benth) Ducke; Erythrina velutina Willd.; e, Enterolobium contortisiliquum (Vell.) Morong.. Thus, an experiment was carried out in the nursery, in the municipality of Serra Talhada, PE. The seeds were subjected to germination treatment. Each species was a treatment, arranged in completely randomized design. The water replenishment was made on the basis of evapotranspiration for the experimental period. At the age of 23, 37, 51, 65, 92 and 120 days after sowing were done samples to determine the dry biomass of plants and their parts, leaves, stems and roots and biometric parameters. With the values of dry biomass and leaf area index were determined the following morphophysiologics indexes, absolute growth rate, relative growth rate, specific leaf area, leaf area ratio, leaf mass ratio. ‘Tamboril’ and ‘Algaroba’ were those which presented the best biometric responses and biomass accumulation, as a result of their performance morphophysiological. In turn, ‘Angico Vermelho’ presented the lowest initial growth when compared with the other species. Keywords: growth analysis, morphophysiologics indexes, caatinga plants, increment rate.