Gallery Forest Species Research Articles

Gallery forest species and water quality of the Okpara River in northern Benin

This study aims to understandf the relationships between water quality, vegetation and human activity in the forest gallery of the Okpara River in northern Benin. Within this framework, floristic surveys and measurements of physicochemical parameters were carried out on 48 sites along the watercourse, located in 8 villages bordering the river. Sociodemographic surveys were also carried out among neighboring populations. The densities of Khaya senegalensis, Mitragyna inermis, Vitellaria paradoxa, Cola laurifolia and Isoberlinia doka of the wooded stratum and the recoveries of Andropogon gayanus, Cassia mimosoïdes, Panicum maximum, Andropogon tectorum, Hyptechis suaveolens and Aptechis suaveolens increased from upstream to downstream. The water can be considered as water of average quality according to the parameters measured. It emerged that the density of Berlinia grandiflora, Isoberlinia doka and Combretum glutinosum on one hand, and the recovery of Andropogon gayanus, Cassia mimosoïdes, Detarium microcarpa and Gynandropsis gynandra on other hand were particularly linked to the physicochemical parameters of water. There was a relative strong relationship between the two groups of parameters with the first canonical coefficient estimated at 0.75. The species richness of shrubs and herbaceous plants, water temperature, Biochemical Oxygen Demand for 5 days and, to a lesser extent, dissolved oxygen contributed to the relationship between the two groups of variables. The importance of human activities from upstream to downstream was also a factor that had a detrimental effect on water quality and on the composition of riparian flora. This information is important for a good sustainable management of these resources.

Long-term streamflow relations with riparian gallery forest expansion into tallgrass prairie in the Southern Great Plains, USA

Though the effects of forests on water yields have been studied since the early 20th century, considerable uncertainty remains regarding streamflow relations in landscapes where forestation of degraded grassland is accompanied by recovery of soil hydrological function. This uncertainty arises because trees may reduce subsurface flow by transpiring water inaccessible to shallow-rooted grasses, but forestation of degraded grassland may also improve soil infiltration capacity, thereby increasing soil water recharge, a prerequisite for baseflow. To determine how riparian gallery forest expansion affected streamflow, we classified a chronosequence of historical aerial photography covering a 78 km 2 watershed equipped with a streamflow gauge. Here we show that in the Council Creek watershed in north-central Oklahoma, the baseflow component of streamflow increased from 1938 to 1992 during which time tree cover increased from 5% to 18% of the watershed area. During this period there were significant increasing trends in precipitation and evapotranspiration, but no significant trends in total streamflow. Stepwise regression indicated that relative to increases in precipitation, increases in forest cover were a better predictor of the observed baseflow increase. Baseflow increases over time were not distributed uniformly throughout the year, but rather occurred only from October through May, during most of which time the primarily deciduous riparian gallery forest species and the herbaceous species that they replaced would have been dormant. Due to confounding factors including elevated precipitation from 1980 to 1992, changing precipitation characteristics, and changing land-use, it was impossible to determine to what extent riparian gallery forest expansion caused the associated baseflow increases. Nonetheless, the method used in the study—relating an historical aerial photography chronosequence to existing long-term stream gauge data—proved to be an inexpensive, efficient, and effective in disproving our hypothesis that riparian gallery forest expansion would reduce baseflows. Further research is needed to better predict how long-term changes in forest cover, the position of forest cover within a watershed, and associated changes in soil and floodplain hydrology will affect streamflow in large mixed land-use watersheds.

Biogeographic barriers in north-western Australia: an overview and standardisation of nomenclature

Within Australia, the biodiverse monsoon tropics are of considerable biogeographical interest. However, this vast and relatively undisturbed area with its high endemicity has only recently become the focus of phylogeographic research (Bowman et al. 2010; Fujita et al. 2010; Melville et al. 2011; Toon et al. 2010). A major challenge to understand the biogeographical processes that have shaped the distribution and diversity of taxa in this region is the lack of detailed fossil and palaeoecological data (Bowman et al. 2010). Although molecular data are able to contribute to our understanding of the biogeographic history of the region (e.g. Lee and Edwards 2008; Toon et al. 2010), relatively few studies have focussed on the geologically old and topographically complex northwest region of Australia (Jennings and Edwards 2005; Fujita et al. 2010; Melville et al. 2011). It is becoming increasingly clear that the biogeographic patterns of this region and the accompanying terminology are complex (Potter et al. 2012).Here we seek to provide an historical overview of the biogeographic nomenclature used for this region in order to bring greater clarity and concordance. We also propose a standard nomenclature that could beused in future biogeographic/phylogeographic studies of north-western Australia. The tropical monsoon region of north-western Australia represents a unique biome comprising a range of habitats. Proterozoic sandstone dominates the landscape and forms ranges and dissected escarpments set within widespread savannah woodlands. Smaller areas of monsoon rainforest, gallery forest and seasonally wet grasslands also occur. The monsoonal climate is characterised by dry winters and wet summers, which drives the vegetation type and associated distribution of taxa (Bowman et al. 2010). Tropical habitats contracted north during aridification in the Miocene and late Pliocene and the monsoonal conditions commenced following the rise of the Tibetan Plateau (3.4–7.2million years ago) and the closing of the Isthmus of Panama (see Bowman et al. 2010; Fujita et al. 2010). However, it was not until the Pleistocene that the monsoonal tropics experienced fluctuating environmental changes associated with global glacial cycles that developed the more contemporary arid-adapted vegetation (reviewed in Bowman et al. 2010; Fujita et al. 2010). The less topographically complex lowlands between the disjunct sandstone outcrops have been identified as potential biogeographic barriers for a wide variety of fauna (e.g. Bowman et al. 2010). Keast (1961) regarded north-west Australia (including both the Kimberley region and Top End of the Northern Territory, Fig. 1) as a single major mesic refuge area (North-West refuge) for Australian fauna. Earlier, Keast (1958) noted that the region of the Joseph Bonaparte Gulf formed a distributional barrier for some mangrove-dependent birds, due to a lack of habitat. After an examination of the North-West refuge bird fauna, Ford (1978) identified the presence of three ‘minor biogeographic barriers’ in the region between the Kimberley and northern Northern Territory (i.e. the Top End). These were identified as ‘arid country round the Joseph Bonaparte Gulf and the Victoria River valley, a discontinuity in sandstone ranges in the region of the Daly River drainage and a stretch of coastline poor in mangroves on western side of the Joseph Bonaparte Gulf’. More specifically, the lowlands of the Daly River drainage were identified as a significant barrier for many sandstone-rangeadapted taxa (Ford 1978). The arid country around the head of the Joseph Bonaparte Gulf (in the region of the Ord and Victoria Rivers) was considered a significant barrier for monsoon and gallery forest species, aswell as formoist grassland taxa,while the break in mangrove habitat in the western Joseph Bonaparte Gulf had significantly influenced mangrove specialists (Ford 1978). This later gap in the distribution of mangroves was subsequently examined in greater detail by Ford (1982), who identified it as a significant biogeographical barrier for mangrove birds, which he termed the ‘Bonaparte Gap’. Subsequently, ‘Bonaparte Gap’ has entered the literature as a more general term

Caractéristiques écologiques et phytosociologiques des galeries forestières de la Réserve de biosphère de la Pendjari (nord-ouest du Bénin)

The flora and plant communities of gallery forests were studied of the Biosphere Reserve of Pendjari using the phytosociological approach. A total of 350 plant species were identified, of which 98 are typically gallery forest species of the Sudanian region of northern Benin. We define five plant communities: (1) the Broenadia salicina—Garcinia ovalifolia comm., (2) the Cassia sieberiana—Terminalia glaucescens comm., (3) the Cola laurifolia—Parinari congensis comm., (4) the Garcinia livingstonei—Combretum acutum comm. and (5) the Ficus congensis—Alchornea cordifolia comm., Since the climate does not substantially vary throughout the reserve, relief and topography turn out to be the two major ecological factors that best discrimate gallery forest types in the study area.

Características funcionais de folhas de sol e sombra de espécies arbóreas em uma mata de galeria no Distrito Federal, Brasil

As matas de galeria são formações florestais que ocupam cerca de 10% da área dos cerrados e representam 1/3 da diversidade de espécies arbóreas ali encontradas. Estudos recentes têm demonstrado a importância dessas florestas em regiões do Brasil central, mas pouco se sabe sobre a fisiologia e plasticidade de espécies de mata de galeria em relação a variantes ambientais, como a irradiação solar. No presente estudo, foram comparados in situ aspectos fisiológicos e nutricionais de folhas de sol e sombra, em dez espécies arbóreas comumente encontradas em matas de galeria. Folhas de sol apresentaram maiores valores de assimilação de CO2 em base de área (Aarea), condutância estomática (gs), rendimento quântico do fotossistema II (ΦFSII) e uma maior fração de centros de reação abertos (qL), enquanto folhas de sombra apresentaram uma maior área foliar específica. Diferenças não foram encontradas para potencial hídrico foliar, assimilação de CO2 em base de massa e para a concentração foliar de macronutrientes. Dos atributos foliares analisados, a abertura estomática e o rendimento quântico do fotossistema II foram os principais fatores atuantes na Aarea em folhas de sol, enquanto em folhas de sombra apenas ΦFSII foi influente. As diferenças encontradas demonstram que, assim como em outras formações florestais, em mata de galeria as espécies arbóreas possuem a capacidade de se aclimatarem às condições contrastantes de sombreamento que ocorrem neste tipo de ambiente.

Leaf phenology and water potential of five arboreal species in gallery and montane forests in the Chapada Diamantina; Bahia; Brazil

The influence of water potential ( Ψ W) on the leaf phenological behaviors of five arboreal species within gallery and montane forests on the eastern slope of the Chapada Diamantina Mountain Range in Bahia State, NE Brazil, was examined to investigate the following questions: (1) Do seasonal variations in rainfall influence the water potential of these species in their natural habitats (gallery and montane forests)? (2) Do the gallery forest species show smaller daily variations in their water potential and greater nocturnal recuperation than montane species? (3) Can the water potentials of these species be used to identify their particular types of leaf phenologies? The species examined were Tibouchina fissinervia and Clusia nemorosa (evergreen with continual leafdrop); Tapirira guianensis and Vochysia pyramidalis (evergreen with concentrated leafdrop), and Maprounea guianensis (brevi-deciduous) were chosen based on their abundance, importance value indices, and contrasting phenological behaviors. The leaf phenologies of all species were similar in both forest types. Evergreen species with continual leafdrop demonstrated leaf budding and leaf fall occurred at low levels during the entire year. Evergreen species with continual leafdrop as well as brevi-deciduous species demonstrated peaks of leaf fall and leaf budding during the dry period. Brevi-deciduous trees remained without leaves for an average of three days. The major episodes of leaf budding occurred during the dry period in all of the species examined. M. guianensis usually demonstrated low predawn ( Ψ PD) and midday ( Ψ MD) water potentials ( Ψ W). C. nemorosa demonstrated the greatest Ψ PD and Ψ MD values and the lowest daily amplitude ( Δ Ψ ), suggesting that this plant used CAM during most of the study period. The majority of the species demonstrated small seasonal differences in Ψ W, and the Ψ PD values indicated a satisfactory nocturnal recuperation of their water status, even during the dry period. The maximum daily amplitude of Ψ W was observed in V. pyramidalis, a species dependent on moist habitats for establishment and growth. No large decrease in Ψ PD was observed during the study period in the species examined here, and all species demonstrated leaf budding during the dry period, suggesting that there were no severe water restrictions in either the gallery or montane forests. However, during dry periods, the species generally demonstrated lower Δ Ψ . This reflects the restriction of transpiration, which according to phenological data, may occur due to different mechanisms, depending on the species. Our data supports the view that there is no strict relationship between decreasing water status in these plants and leaf fall.

Fenologia reprodutiva e disponibilidade de frutos de espécies arbóreas em mata ciliar no rio Formoso, Mato Grosso do Sul

Estudos fenológicos são importantes para o entendimento da dinâmica dos ecossistemas florestais, principalmente quando avaliam a disponibilidade de frutos para a fauna. As matas ciliares são formações vegetais que ocorrem ao longo dos cursos d'água e desempenham papel importante na formação dos corredores de fluxo gênico, podendo interligar populações vegetais que foram separadas pelo processo de fragmentação. O presente trabalho procurou entender como varia a fenologia reprodutiva e a disponibilidade de frutos de espécies arbóreas em mata ciliar do rio Formoso, município de Bonito, Mato Grosso do Sul, entre estações e ao longo de um ano. Foram feitas observações mensais em 29 espécies vegetais, 31% anemocóricas e 68,9% zoocóricas, das fenofases floração e frutificação, e estimada a produção de frutos por contagem no chão da floresta. A floração ocorreu principalmente na transição entre as estações seca e chuvosa e a frutificação na estação chuvosa e não apresentaram correlações significativas com a pluviosidade ou a temperatura, apesar do padrão sazonal. As espécies Attalea phalerata e Guibourtia hymenifolia destacaram-se pelo fornecimento de frutos para a fauna de frugívoros na estação seca, período de maior escassez de frutos na mata ciliar.

Crescimento inicial de Piptadenia gonoacantha (Leguminosae, Mimosoideae) sob inundação em diferentes níveis de luminosidade

This study focus on ecological aspects of flooding on five month old seedlings of Piptadenia gonoacantha, a Gallery forest species. Seedling growth rates were evaluated on three levels of sun light (100%, 70% and 40%) and two soil moisture conditions (field capacity and flooded). Flooding reduced aerial and root growth. There was no interaction between light intensity and flooding, except for foliar dry matter (60 days) and top/root ratio (20 days). Full sun light seedlings under flooding had 67% lower foliar dry matter production than shaded ones, after 60 days. Flooded seedlings in all three light levels, had hypertrophic lenticels on submerged stems, after 20 days. In additon, flooding induced root decomposition but no adventicious roots were observed. After 60 days of flooding, seedlings of P. gonoacantha presented 100 % survival and no significant injury on the top portion.

Fern Spore Morphology and Spore Rain of a Preserved Cerrado Region in Southeast Brazil (Reserva Biologica e Estacao Experimental de Moji Guacu, Sao Paulo)

Fern Spore Morphology and Spore Rain of a Preserved Cerrado Region in Southeast Brazil (Reserva Biologica e Estacao Experimental de Moji Guacu, Sao Paulo)

A study of the origin of central Brazilian forests by the analysis of plant species distribution patterns

The floristic nature of central Brazilian forests, as well as their links to other main forest formations of eastern tropical South America, is assessed by means of multivariate analyses of 106 existing floristic checklists and by the analysis of a series of dot-maps showing the distribution of 55 woody species. Most species of central Brazilian forests seem to conform to two main distribution patterns: (1) species of deciduous and semideciduous forests are dependent essentially on the occurrence of patches of soils of intermediate to high fertility within the cerrado domain and tend to be distributed mostly along a northeast-southwest arch connecting the caatingas to the chaco boundaries; (2) considerable numbers of gallery forest species are dependent on high soil moisture and many appear to link the Amazonian and Atlantic rainforests by crossing the cerrado region in a northwest-southeast route via the dendritic net of gallery forests. Many gallery forest species are habitat generalists, some even occurring in the cerrado vegetation. Nevertheless, significant numbers of gallery endemics are also present. Galleries of the west and north of the Cerrado Province show stronger floristic links to the Amazonian rainforests, while those of the centre and south show stronger affinity with the montane semideciduous forests of southeastern Brazil. Present-day distribution patterns are discussed in the light of the current knowledge of palaeoenvironmental changes in the Neotropics.A natureza florística das florestas do Brasil Central bem como seus laços com outras grandes formaçõs florestais da América do Sul trópico-oriental é avaliada por meio de análises multivariadas de 106 listagens florísticas existentes e pela análise de uma série de mapas de distribuição geográfica de 55 espécies lenhosas. A maioria das espécies das florestas do Brasil Central parece ajustar-se a dois grandes padrões de distribuição: (1) espécies de florestas decíduas e semidecíduas dependem essencialmente da ocorrência de manchas de solos de média a alta fertilidade dentro do domínio dos cerrados e tendem a se distribuir principalmente ao longo de um arco nordeste-sudoeste que conecta as caatingas às fronteiras do chaco; (2) um considerável número de espécies de florestas de galeria depende basicamente de alta umidade no solo e muitas delas parecem distribuir-se das florestas pluviais da Amazônia até as Atlânticas, cruzando a região do cerrado numa rota noroeste-sudeste através da rede dendrítica de florestas de galeria. Muitas espécies de floresta de galeria são generalistas quanto ao habitat, sendo inclusive compartilhadas com os cerrados. Um significativo número, entretanto, é endêmico das florestas de galena. As galerias do oeste e norte da Província do Cerrado mostram uma ligação florística mais forte com as florestas pluviais da Amazônia, ao passo que as do centro e sul mostram uma estreita afinidade com as florestas semideciduas montanas do sudeste brasileiro. Os padrões de distribuição geográfica atuais que emergiram das análises são discutidos sob a luz do presente conhecimento sobre as mudanças paleoambientais nos Neótropicos.

Flooding tolerance: a reinterpretation of Crawford's metabolic theory

SynopsisThe flooding tolerance strategy of three tropical gallery forest species,Sebastiana klotzchyana, Hymenaea courbarilvar.stilbocarpaandChorisia speciosawas studied. Data from the flood-intolerantSchyzolobium parahybahave been included for comparison.In the case ofS. klotzchyanaflooding induced an acceleration of glycolysis, with ethanol as the sole end product of anaerobic metabolism. Oxygen diffusion to the root system was not detectable.The results obtained forH. courbarilandC. speciosashow a compromise between metabolic and morpho-anatomical adaptations to enable them to occupy seasonally flooded areas. In both species, at the onset of the stress, the roots stop producing high amounts of ethanol and lactate. diverting part of the pyruvate produced to malate. The amount of pyruvate converted into malate is determined by the amount of oxygen diffused from the aerial part to the roots. This is used to oxidise pyruvate through Krebs' cycle and the excess is converted to malate. ATP production in the root system is predominantly aerobic and therefore not linked to malate production.The low level of acceleration of the fermentative pathway, coupled with the lack of oxygen diffusion to the root system, resulted in a significant decrease in the growth rate ofS. parahyba.

Composição florística e estrutura comunitária da floresta de galeria do córrego da Paciência, Cuiabá, (MT)

A floresta de galeria de um dos braços do córrego da Paciência, no sopé da chapada dos Guimarães, Mato Grosso (15º 21'S. 55º 49' W), foi inventariada por meio de 67 parcelas de 30m² (0,201 ha), sendo amosdos os indivíduos com circunferência ao nível do solo > 9cm em três setores da floresta; Nascentes, Vereda e Cachoeira. Foram calculados os parâmetros fitossociológicos das espécies e das famílias botânicas para toda a área amostral e para cada um dos três setores da floresta. Foram obtidas medidas de dissimilaridade florística e estrutural entre os três setores amostrais e medidas de dissimilaridade florística entre a floresta do presente estudo e cinco outras florestas riparias do Distrito Federal e dos estados de São Paulo e Mato Grosso. As seis florestas apresentaram entre si índices muito altos de dissimilaridade florística, embora algumas delas apresentassem espécies em comum entre as mais abundantes. Os três setores amostrais mostraram igualmente uma considerável dessemelhança florística e estrutural entre si. O clima, os solos e a geomcrfologia das bacias hidrográficas são evocados como responsáveis pelas diferenças interregionais entre as florestas riparias. Já as dessemelhanças intrarregionais podem ser atribuídas à fertilidade dos solos e, sobretudo, ao regime de água nos solos e nos próprios rios, os quais, por sua vez, variam com a topografia local. Os padrões de distribuição espacial marcadamente diferentes que podem ser observados para várias espécies de árvores podem ser atribuídos à elevada heterogeneidade ambiental, peculiar às florestas de galeria.