Marianna Dixo

Using ecological thresholds to evaluate the costs and benefits of set-asides in a biodiversity hotspot

Cost-effective conservation on private land How affordable is biodiversity conservation in a fragmented landscape? Banks-Leite et al. asked this question for the biodiversity hotspot of the Brazilian Atlantic Forest. An annual investment of <10% of Brazils agricultural subsidies could support effective ecological restoration on private lands. This would increase biodiversity in set-aside land to the same level observed in protected areas. The cost-effectiveness of this scheme suggests a path forward for conservation strategies in other similarly mixed landscapes, too. Science, this issue p. 1041 A small portion of Brazil’s agricultural subsidies would be enough to preserve private land in the Brazilian Atlantic Forest. Ecological set-asides are a promising strategy for conserving biodiversity in human-modified landscapes; however, landowner participation is often precluded by financial constraints. We assessed the ecological benefits and economic costs of paying landowners to set aside private land for restoration. Benefits were calculated from data on nearly 25,000 captures of Brazilian Atlantic Forest vertebrates, and economic costs were estimated for several restoration scenarios and values of payment for ecosystem services. We show that an annual investment equivalent to 6.5% of what Brazil spends on agricultural subsidies would revert species composition and ecological functions across farmlands to levels found inside protected areas, thereby benefiting local people. Hence, efforts to secure the future of this and other biodiversity hotspots may be cost-effective.

Ferns, frogs, lizards, birds and bats in forest fragments and shade cacao plantations in two contrasting landscapes in the Atlantic forest, Brazil

The traditional shade cacao plantations (cabrucas) of southern Bahia, Brazil, are biologically rich habitats, encompassing many forest-dwelling species. However, a critical question for the conservation management of this specific region, and the highly fragmented Atlantic forest in general, is to what extent the conservation value of cabrucas relies on the presence of primary forest habitat in the landscape. We investigated the relative importance of cabrucas and forests for the conservation of five diverse biological groups (ferns, frogs, lizards, birds and bats) in two contrasting landscapes in southern Bahia, one dominated by forest with some interspersed cabrucas, and one dominated by cabrucas with interspersed forest fragments. The community structure (richness, abundance and diversity) of all biological groups differed between cabrucas and forests, although these differences varied among groups. A high number of forest species was found in the cabrucas. However, there were pronounced differences between the two landscapes with regard to the ability of cabrucas to maintain species richness. Irrespective of the biological group considered, cabrucas located in the landscape with few and small forest fragments supported impoverished assemblages compared to cabrucas located in the landscape with high forest cover. This suggests that a greater extent of native forest in the landscape positively influences the species richness of cabrucas. In the landscape with few small forest fragments interspersed into extensive areas of shade cacao plantations, the beta diversity of birds was higher than in the more forested landscape, suggesting that forest specialist species that rarely ventured into cabrucas were randomly lost from the fragments. These results stress both the importance and the vulnerability of the small forest patches remaining in landscapes dominated by shade plantations. They also point to the need to preserve sufficient areas of primary habitat even in landscapes where land use practices are generally favorable to the conservation of biodiversity.

Herpetofauna de serrapilheira da Reserva Florestal de Morro Grande, Cotia (SP)

We present an annotated list of anurans, lizards, and snakes registered at the Reserva Florestal de Morro Grande, Cotia, State of Sao Paulo. The list includes 27 anurans, five lizards and three snakes captured mainly in pitfall traps and encountered during field surveys. Eighteen species of anurans captured from pitfall traps were used to compare six areas sampled inside the Reserve, three in secondary forest and three in mature forest. The analysis showed significant differences among secondary and mature forest. We also compared the similarity of the anurofauna of the Reserve to those of six other Atlantic Forest localities inside the State. The anurofauna found at the Reserve is more similar to that found in other localities at the Atlantic plateau than those from coastal plains. The small number of reptiles specimens captured in pitfall traps precluded the same analyses made for anurans. The low abundance of these animals inside the forest limited our ability to compare different areas. There is an evident lack of information on the biology, distribution and conservation status on Brazilian herpetofauna that could be filled by inventory and monitoring of this fauna. Only natural history knowledge can lead to efficient conservation planning of these species.

Para que servem os inventários de fauna

Inventarios de fauna acessam diretamente a diversidade de uma localidade, em um determinado espaco e tempo. Os dados primarios gerados pelos inventarios compoem uma das ferramentas mais importantes na tomada de decisoes a respeito do manejo de areas naturais. Entretanto, varios problemas tem sido observados em diversos niveis relacionados aos inventarios de fauna no Brasil e vao desde a formacao de recursos humanos ate a ausencia de padronizacao, de desenho experimental e de selecao de metodos inadequados. Sao apresentados estudos de caso com mamiferos, repteis, anfibios e peixes, nos quais sao discutidos problemas como variabilidade temporal e metodos para deteccao de fauna terrestre, sugerindo que tanto os inventarios quanto os programas de monitoramento devam se estender por prazos maiores e que os inventarios devem incluir diferentes metodologias para que os seus objetivos sejam plenamente alcancados.

Herpetofauna dos remanescentes de Mata Atlântica da região de Tapiraí e Piedade, SP, sudeste do Brasil

We present the species list of amphibians and reptiles registered in continuous and fragmented Atlantic Forest remnants at Tapirai and Piedade municipalities, Atlantic Plateau of Sao Paulo, Brazil. We sampled 21 localities, 15 located within unprotetcted forest fragments and six located at Parque Estadual do Jurupara, the single legal protected area in this region and surroundings. We recorded 47 anurans, one gymnophiona, seven lizards, one amphisbenian, 46 snakes, and one turtle. The specimes were captured by pitfall traps with drift fences, visual and auditive surveys, incidental encounters, local collectors, and, for snakes, by recording scientific collection records. Sampling methods were effective in documenting local herpetofauna, showing the adequacy of the use of complementary methods. Forest remnants at Tapirai and Piedade have typical species of Atlantic Forest areas, and show higher species richness in comparison with other lists in the Atlantic Plateau. The presence of species known from few localities, or present in threatened species lists, shows that the Atlantic Forest remnants in this region need conservation attention. Although still harboring high herpetofaunal diversity, the remnants are threatened by the effects of forest fragmentation.

Are leaf-litter frogs and lizards affected by edge effects due to forest fragmentation in Brazilian Atlantic forest?

Edge effects encompass biotic and abiotic changes resulting from the interaction between two different habitat types (Murcia 1995). Edge habitats are ecologically distinct from patch interiors, and understanding how ecological patterns change near edges is important in understanding landscape-level dynamics such as the impacts of fragmentation (Ries et al . 2004). Abiotic conditions at the forest edge, such as increased wind and solar radiation, increased fluctuations in temperature, and decreased humidity, may affect forest-adapted organisms (Harper et al . 2005, Murcia 1995). So, edges may affect lizards and amphibians due to their physiological needs (Lehtinen et al . 2003, Vallan 2000). Anurans are considered sensitive to environmental changes due to their permeable skin, shell-less eggs and use of land as well as freshwater habitats (Vallan 2000). Changes in vegetation structure and microclimate are likely to be the predominant factor affecting amphibian abundances across edges (Jellinek et al . 2004, Marsh & Pearman 1997, Schaepfer & Gavin 2001, Urbina-Cardona et al . 2006).

A new genus of microteiid lizard from the Atlantic forests of State of Bahia, Brazil, with a new generic name for Colobosaura mentalis, and a discussion of relationships among the Heterodactylini (Squamata, Gymnophthalmidae)

Abstract A new genus and species of microteiid lizard is described from a series of specimens obtained in the leaf litter at Una (15°10′S, 39°03′W) in the Atlantic forest of southern Bahia, Brazil. It is characterized by the presence of prefrontals, frontoparietals, parietals, and interparietal; parietals longer than wide; distinct ear openings and eyelids; two pairs of genials, absence of collar and occipital scales; dorsal scales anteriorly smooth and becoming gradually lanceolate and mucronate posterior to the forelimb; and four regular transverse series of smooth ventrals that are longer than wide, identical in size. A phylogenetic analysis based on external morphology, osteology, and molecular data confirms this new lizard as a member of the Heterodactylini radiation of Gymnophthalminae. The topology recovered by maximum parsimony (MP) analyses reveals that its closest relatives are the sister taxa Colobosaura modesta and Iphisa elegans (BS  =  < 50%; Bremer value  =  2) and the partitioned Bremer indexes indicated that the largest contribution to this relationship comes from morphology; Colobosaura mentalis, for which a new generic name is here proposed, is basal to this radiation. Our analyses confirm a previous hypothesis suggesting Stenolepis as a member of the Heterodactylini radiation and that the clade composed of Colobodactylus and Heterodactylus is the sister group of the clade formed by Colobosaura mentalis-Stenolepis (BS  =  100; Bremer value  =  18), Colobosaura modesta-Iphisa (BS  =  < 50%; Bremer value  =  1), and the new genus here described. The support for Heterodactylini monophyly, on the basis of combined MP analyses is higher (BS  =  96, Bremer value  =  11) than that previously found in molecular-based studies only. Partitioned Bayesian methodology combining molecular and morphological data sets recovered the new genus as the sister taxon (PP  =  0.94) of the clade (PP  =  0.94) formed by I. elegans-C. modesta (PP  =  0.51) and C. mentalis-S. ridleyℝ (PP  =  1.0). An alternative topology demonstrating a paraphyletic Heterodactylini is only weakly supported (PP  =  0.63). Based on the MP topology we discuss tentative scenarios for the evolution of Heterodactylini.

The matrix-tolerance hypothesis: an empirical test with frogs in the Atlantic Forest.

The matrix-tolerance hypothesis suggests that the most abundant species in the inter-habitat matrix would be less vulnerable to their habitat fragmentation. This model was tested with leaf-litter frogs in the Atlantic Forest where the fragmentation process is older and more severe than in the Amazon, where the model was first developed. Frog abundance data from the agricultural matrix, forest fragments and continuous forest localities were used. We found an expected negative correlation between the abundance of frogs in the matrix and their vulnerability to fragmentation, however, results varied with fragment size and species traits. Smaller fragments exhibited stronger matrix-vulnerability correlation than intermediate fragments, while no significant relation was observed for large fragments. Moreover, some species that avoid the matrix were not sensitive to a decrease in the patch size, and the opposite was also true, indicating significant differences with that expected from the model. Most of the species that use the matrix were forest species with aquatic larvae development, but those species do not necessarily respond to fragmentation or fragment size, and thus affect more intensively the strengthen of the expected relationship. Therefore, the main relationship expected by the matrix-tolerance hypothesis was observed in the Atlantic Forest; however we noted that the prediction of this hypothesis can be substantially affected by the size of the fragments, and by species traits. We propose that matrix-tolerance model should be broadened to become a more effective model, including other patch characteristics, particularly fragment size, and individual species traits (e.g., reproductive mode and habitat preference).

A new species of Leposoma (Squamata, Gymnophthalmidae) from the remnant Atlantic forests of the state of Bahia, Brazil

Leposoma puk, a new species of the scincoides group is described from the Atlantic forests of southern state of Bahia, Brazil. The new species is characterized by a single frontonasal; elongate dorsal and lanceolate ventral scales arranged in diagonal rows; weakly striated or smooth scales on top of head; a longer than wide interparietal, with almost straight lateral margins; 17-18 pores; third supraocular the largest one, wider than long and clearly rectangular in shape; a suture between frontal and frontoparietal scales coincident with the middle of the third supraocular; and, a black pigmentation in the venter or along venter margins in males. The discovery of this new species, sympatric with Leposoma annectans, L. nanodactylus, and L. scincoides ranks the Atlantic Rainforest region of Southern Bahia first in species diversity for the genus. Zoogeography and speciation of Leposoma of the scincoides group are discussed.

Are corridors, fragment size and forest structure important for the conservation of leaf-litter lizards in a fragmented landscape?

To investigate the implications of forest fragmentation for conservation of leaf-litter lizards the importance of fragment size, corridors and forest structure was examined in 20 forest fragments and six localities within a continuous forest in the Atlantic Plateau of Sao Paulo state, Brazil. The fragments were 2–276 ha in area and had different degrees of connectivity depending on the presence or absence of corridors. Two species of lizards were dominant, Ecpleopus gaudichaudii and Enyalius perditus . Variation in forest structure among sites was important only in explaining the abundance of E. perditus . Regardless of variation in forest structure, lizard species composition, total lizard abundance, number of species and abundance of E. perditus were sensitive to fragmentation per se but not to fragment size or corridor linkage. The inhospitable matrix surrounding fragments is probably what determines the presence and abundance of E. perditus and the higher lizard richness in continuous forests. These conditions may have prevented lizard species from recolonizing the forest fragments. Our results emphasize that the conservation of this leaf-litter fauna depends on the maintenance of large tracts of continuous forests and not on the size of fragments or on the presence of forest connections. Strategies for conservation of leaf-litter lizards in such highly fragmented Atlantic Forest landscapes should consider the enlargement of landscape connectivity between fragments and continuous forest, allowing the latter areas to act as a source of individuals for fragments.