G. Wilson Fernandes

Ecology and evolution of plant diversity in the endangered campo rupestre: a neglected conservation priority

BackgroundBotanists, ecologists and evolutionary biologists are familiar with the astonishing species richness and endemism of the fynbos of the Cape Floristic Region and the ancient and unique flora of the kwongkan of south-western Australia. These regions represent old climatically-buffered infertile landscapes (OCBILs) that are the basis of a general hypothesis to explain their richness and endemism. However, few ecologists are familiar with the campo rupestre of central and eastern Brazil, an extremely old mountaintop ecosystem that is both a museum of ancient lineages and a cradle of continuing diversification of endemic lineages.ScopeDiversification of some lineages of campo rupestre pre-dates diversification of lowland cerrado, suggesting it may be the most ancient open vegetation in eastern South America. This vegetation comprises more than 5000 plant species, nearly 15xa0% of Brazil’s plant diversity, in an area corresponding to 0.78xa0% of its surface. Reviewing empirical data, we scrutinise five predictions of the OCBIL theory, and show that campo rupestre is fully comparable to and remarkably convergent with both fynbos and kwongkan, and fulfills the criteria for a classic OCBIL.ConclusionsThe increasing threats to campo rupestre are compromising ecosystem services and we argue for the implementation of more effective conservation and restoration strategies.

Toward an old‐growth concept for grasslands, savannas, and woodlands

We expand the concept of “old growth” to encompass the distinct ecologies and conservation values of the worlds ancient grass-dominated biomes. Biologically rich grasslands, savannas, and open-canopy woodlands suffer from an image problem among scientists, policy makers, land managers, and the general public, that fosters alarming rates of ecosystem destruction and degradation. These biomes have for too long been misrepresented as the result of deforestation followed by arrested succession. We now know that grassy biomes originated millions of years ago, long before humans began deforesting. We present a consensus view from diverse geographic regions on the ecological characteristics needed to identify old-growth grasslands and to distinguish them from recently formed anthropogenic vegetation. If widely adopted, the old-growth grassland concept has the potential to improve scientific understanding, conservation policies, and ecosystem management.

Tyranny of trees in grassy biomes.

![Figure][1] nnHighland grassland in Brazil is considered a forest landscape restoration opportunitynnPHOTO: G. W. FERNANDESnnTree planting, fire suppression, and exclusion of megafaunal herbivores (native or domestic) are ecologically reasonable restoration strategies in deforested landscapes

Herbivory by Chewing and Sucking Insects on Tabebuia ochracea

Our study addresses the influence of Tabebuia ochracea leaf variation on insect herbivores. We studied the roles of leaf size, age, and hairyness in the feeding choices of chewing and sucking herbivores. The T. ochracea studied belonged to a single clone, thus decreasing the potential influences of host plant genetic and chemical variation on herbivore choice. Young and mature leaves showed the same amount of damage from chewing herbivores in the field. Homopterans (Rhabdotalebra spp.) and hemipterans (Tingis tecomae) occurred primarily on large leaves. The leaf area consumed by grasshoppers in a laboratory experiment was higher on young leaves than on mature leaves. Nevertheless, there was no difference in the choice by Rhabdotalebra spp. and T. tecomae for young vs mature leaves of T. ochracea. Mature, large leaves were chosen over mature, small leaves by Rhabdotalebra spp. and T. tecomae. In a laboratory experiment, T. tecomae did not choose between leaf circles of same size taken from large or small leaves, indicating that the most relevant factor in its food choice was leaf size. Nevertheless, Rhabdotalebra spp. significantly chose leaf circles taken from large leaves, indicating that leaf trichome density was an important component in its food choice. The differential distribution of small and large leaves was important in the food selection by T. tecomae; whereas, trichome density was a relevant factor in food selection by Rhabdotalebra spp.

Efeitos do sexo, do vigor e do tamanho da planta hospedeira sobre a distribuição de insetos indutores de galhas em Baccharis pseudomyriocephala Teodoro (Asteraceae)

Several hypotheses have been proposed to explain the patterns of host plant utilization by herbivorous insects in natural communities. We tested four hypotheses aiming to understand the pattern of attack by gall-inducing insects on the dioecious shrub, Baccharis pseudomyriocephala (Asteraceae). The shrub occurs in the Parque Estadual do Itacolomi, Southeastern Brazil, and supports ten species of galling insects. The following hypotheses were tested: i) male plants are more attacked by galling insects than female plants; ii) larger plant modules are preferentially attacked by galling insects; iii) galling insects perform better on larger modules than on smaller modules; iv) galling insects increase in abundance with meristematic availability. To address these questions, 240 plants (120 of each sex) were sampled in both reproductive and vegetative periods. We recorded the growth rate (4 cm), inflorescence and fruit production, attack rates of the galling insects, and their survivorship and mortality per shoot (module). Modules were separated into size classes (cm) and analyzed by regressions and ANCOVAs. Module size and reproductive effort were positively correlated with host plant size. We did not observe any effect of host plant gender on either variables. In the same way, host plant sex did not show any influence on the abundance and richness of galling insects. Although the abundance of galling insects showed a positive correlation with shoot size, the trend disappeared when the analyses were performed taking into consideration the number of galls per unit of growth (number of galls/cm of shoot) or biomass (number of galls/dry weight). Larval survivorship was not influenced by shoot size. Also, we observed that the abundance of one species of hemipteran galling insect showed a positive relation with leaf biomass. Therefore, we conclude that gender and vigor of this plant species do not influence the community structure of its galling herbivores.

Vegetation composition and structure of some Neotropical mountain grasslands in Brazil

The description and understanding of plant communities is fundamental for the implementation of conservation or restoration programs, especially when these communities are highly threatened and need to be restored. Campos rupestres, some Neotropical mountain grasslands located in central Brazil and part of the Cerrado biome (covering 2 million km2) host unique plant communities, currently threatened by quarrying and mining. The grassy matrix of campos rupestres, has long been considered a rich mosaic under the control of local topography and the nature of substrate, but this affirmation has not been well studied. We analyzed whether plant communities varied in relation to edaphic factors within the stony substrate and the sandy substrate of this grassy matrix. We selected 5 sites where occur both grasslands on stony substrate and on sandy substrate, and we carried out vegetation surveys and soil analyses. We counted 222 plant species within our communities, among which 38.6% are exclusively found on campos rupestres. Our results show that both soil-types are strongly acidic, nutrient poor and exhibit a seasonal variation. Phosphorus increases and pH and organic carbon decrease during the dry season. Stony soils are slightly richer in nutrients than sandy soils and differences in soil granulometry and composition have led to the formation of distinct plant communities. Some species are confined to either one or the other grassland-type, which makes the plant composition of each community unique. Variations in edaphic factors generate heterogeneous grasslands favorable to a high plant diversity. Conservation programs and restoration actions have to maintain or recreate this heterogeneity. The presence of distinct plant communities implies that different strategies might be adopted to improve the restoration of these ecosystems.

Seed and Seedling Ecophysiology of Neotropical Melastomataceae: Implications for Conservation and Restoration of Savannas and Rainforests1

Abstract We review the patterns of fruit maturation, dispersal, germination, seed bank formation, and seedling establishment of the Melastomataceae in two Neotropical biodiversity hotspots, the Brazilian cerrado and the Atlantic rainforest. Studies on seed biology of the Melastomataceae are relevant because this family is ubiquitous, species-rich, and dominant in these two hotspots, and its increased relative importance is anticipated under the current scenario of habitat loss and forest fragmentation. The life-history traits of this pioneer-dominated family are quite variable in terms of fruiting phenology and seedling establishment, but less so for dispersal ecology and seed germination. Our knowledge of this seed biology is used to infer on the predicted impacts of global change and forest fragmentation for tropical forest and cerrado melastomes. Species in the Melastomataceae may be key in restoration ecology, and we discuss how seed- and seedling-based restoration techniques can assist ecosystem recovery. Resumen Revisamos los patrones de maturación de frutos, dispersión, germinación, banco de semillas y establecimiento de plantas de Melastomataceae en dos hotspots debiodiversdad, el cerrado y la Mata Atlántica. Estudios de semillas de Melastomataceae son importantes porque la familia presenta alta diversidad y es dominante en un gran rango de hábitats. Además, resulta que la familia tiene prevista su importancia aumentada en escenarios de fragmentación de bosques. Las características de história de vida de esta familia de plantas pioneras es muy variable con respecto a la fenología reproductiva y establecimiento de plántulas, pero no tanto con respecto a la ecología de dispersión de semillas y germinación. La biología de semillas embasa la discusión sobre los impactos de los cambios globales y fragmentación de bosques en Melastomataceae de sabanas y bosques tropicales. Especies de Melastomataceae pueden ser claves para la ecología de la restauración y discutimos como las técnicas de restauración basadas en semillas y plántulas pueden ayudar en la restauración.

A 15-year post evaluation of the fire effects on ant community in an area of Amazonian forest

Fire represents an important disturbance to ant communities in areas of fire regime. Otherwise, little is known about the effects of fire on ant communities in areas of non-fire regimes, such as in the Amazonian region. We evaluated the long-term effect of fire on ant species richness in a rain forest (Bacaba Plateau) burned 15-years ago and compare our data with the data of primary unburned forest. A total of 85 ant species distributed in 21 genera and 14 tribes were collected; among them, 72 and 44 species were found on the litter and vegetation, respectively. The fire damaged forest studied supports an intermediate richness of ants when compared to a primary unburned rain forest in the same region. A comparative analysis of ant species richness showed that the Bacaba Plateau presented a different ant fauna when compared with the primary unburned forests, suggesting that fire can alter ant species composition. Although, our results cannot be conclusive on the effects of fire on ant community, they represent a pioneer data on human induced fire in tropical rain forests.

Variation of arbuscular mycorrhizal fungal communities along an altitudinal gradient in rupestrian grasslands in Brazil

Variation in arbuscular mycorrhizal fungi (AMF) communities is described for the first time in rupestrian grasslands in Brazil along an altitudinal gradient of 700xa0m (800 to 1400xa0mxa0a.s.l.). Hypotheses tested were that soil properties influence the variation in AMF communities and that the frequency of the most common species of AMF is inversely influenced by the richness of other AMF. Field and laboratory data were collected on AMF community composition, richness, density, and frequency in the altitudinal gradient, and the relationships with several physical–chemical soil properties and altitude were evaluated. Fifty-one species of AMF were recorded, with 14 species being reported as possibly new to science and nine species representing new records for Brazil. This single elevation gradient alone contains 22xa0% of the known world diversity of AMF. Soil properties and AMF community density and richness varied significantly along the elevation (pu2009<u20090.05). AMF density and richness were higher at the intermediate altitude, while AMF species composition differed statistically among thexa0altitudes.

The Megadiverse Rupestrian Grassland

The Rupestrian Grassland is an ancient ecosystem characterized by high herbaceous species richness, high endemism, and unique species compositions. The vegetation and habitats in the Rupestrian Grassland are maintained by edapho-climatic factors that limit tree growth and distribution, frequent fires, and, possibly, herbivory. The synergism of the environmental filters caused by these factors and interactions amongst species are the drivers of biodiversity and ecosystem services in this megadiverse environment. But this natural heritage is under threat due to human induced disturbances and by climate change . This book brings to light the most updated synthesis on this unique and paramount ecosystem.