Alexandre Camargo Martensen

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.

Associations of Forest Cover, Fragment Area, and Connectivity with Neotropical Understory Bird Species Richness and Abundance

Theoretical and empirical studies demonstrate that the total amount of forest and the size and connectivity of fragments have nonlinear effects on species survival. We tested how habitat amount and configuration affect understory bird species richness and abundance. We used mist nets (almost 34,000 net hours) to sample birds in 53 Atlantic Forest fragments in southeastern Brazil. Fragments were distributed among 3 10,800-ha landscapes. The remaining forest in these landscapes was below (10% forest cover), similar to (30%), and above (50%) the theoretical fragmentation threshold (approximately 30%) below which the effects of fragmentation should be intensified. Species-richness estimates were significantly higher (F= 3715, p = 0.00) where 50% of the forest remained, which suggests a species occurrence threshold of 30-50% forest, which is higher than usually occurs (<30%). Relations between forest cover and species richness differed depending on species sensitivity to forest conversion and fragmentation. For less sensitive species, species richness decreased as forest cover increased, whereas for highly sensitive species the opposite occurred. For sensitive species, species richness and the amount of forest cover were positively related, particularly when forest cover was 30-50%. Fragment size and connectivity were related to species richness and abundance in all landscapes, not just below the 30% threshold. Where 10% of the forest remained, fragment size was more related to species richness and abundance than connectivity. However, the relation between connectivity and species richness and abundance was stronger where 30% of the landscape was forested. Where 50% of the landscape was forested, fragment size and connectivity were both related to species richness and abundance. Our results demonstrated a rapid loss of species at relatively high levels of forest cover (30-50%). Highly sensitive species were 3-4 times more common above the 30-50% threshold than below it; however, our results do not support a unique fragmentation threshold.

The Brazilian Atlantic Forest: A Shrinking Biodiversity Hotspot

The Neotropical Atlantic Forest is one of the world’s top biodiversity hotspot. Originally, the forest extended over 1.5 million km2 along the South American Atlantic coast, covering tropical and subtropical climates across highly heterogeneous relief conditions, which led to outstanding levels of endemism and species richness. Unfortunately, the Atlantic Forest has been historically altered by humans, which has resulted in severe habitat loss and fragmentation. The forest cover is now reduced to around 12% of its original extent, including regenerating areas and degraded forests, which are mostly spread in small fragments. As a result, many species are currently threatened to global extinction, with populations collapsing on local and regional scales. In this chapter, we reviewed the state of the art of Atlantic Forest biodiversity knowledge, pointing out the main achievements obtained by several research groups during the last decades. Additionally, we (1) propose a new sub-division of biogeographical sub-regions into 55 sectors considering 2,650 sub-watersheds, using niche theory and bioclimatic data; (2) describe the original and present distribution of the Atlantic Forest; and (3) relate the forest distribution to elevation and geomorphometric information (aspect and terrain orientation). Forest protection and restoration efforts, and potential ecosystem services are also examined as key topics driving the future of the Atlantic Forest biodiversity.

Long-term carbon loss in fragmented Neotropical forests

Tropical forests play an important role in the global carbon cycle, as they store a large amount of carbon (C). Tropical forest deforestation has been identified as a major source of CO2 emissions, though biomass loss due to fragmentation--the creation of additional forest edges--has been largely overlooked as an additional CO2 source. Here, through the combination of remote sensing and knowledge on ecological processes, we present long-term carbon loss estimates due to fragmentation of Neotropical forests: within 10 years the Brazilian Atlantic Forest has lost 69 (±14) Tg C, and the Amazon 599 (±120) Tg C due to fragmentation alone. For all tropical forests, we estimate emissions up to 0.2 Pg C y(-1) or 9 to 24% of the annual global C loss due to deforestation. In conclusion, tropical forest fragmentation increases carbon loss and should be accounted for when attempting to understand the role of vegetation in the global carbon balance.

As aves da Reserva Florestal do Morro Grande (Cotia, SP)

A total of 198 bird species was recorded in the Morro Grande Forest Reserve. The survey was conducted between 2001 and 2003 using qualitative and quantitative (mist-nets and point counts) methods. The number of species recorded with the quantitative methods was lower if compared with the total number of species registered in the reserve, with 98 species recorded with point counts and 46 captured with mist nets. In spite of this difference, both methods detected similar patterns of species distribution, showing a huge heterogeneity in the bird community along the reserve, with the main differences between the mature forest, richer and with several exclusive species, and secondary forests. However, even among secondary forest plots differences could be seen. Besides the large size of the Reserve and the fact that it is well linked with the continuous forest of the Serra de Paranapiacaba, several species have already disappeared from the Reserve. These are mainly species under a high hunting pressure and the large canopy frugivores. Even though, the Morro Grande Reserve harbors a high diversity of species, with several endemic and threatened species. The conservation and restoration of Morro Grande forests represent important actions for bird conservation in the Atlantic forest.

ATLANTIC‐CAMTRAPS: a dataset of medium and large terrestrial mammal communities in the Atlantic Forest of South America

Our understanding of mammal ecology has always been hindered by the difficulties of observing species in closed tropical forests. Camera trapping has become a major advance for monitoring terrestrial mammals in biodiversity rich ecosystems. Here we compiled one of the largest datasets of inventories of terrestrial mammal communities for the Neotropical region based on camera trapping studies. The dataset comprises 170 surveys of medium to large terrestrial mammals using camera traps conducted in 144 areas by 74 studies, covering six vegetation types of tropical and subtropical Atlantic Forest of South America (Brazil and Argentina), and present data on species composition and richness. The complete dataset comprises 53,438 independent records of 83 species of mammals, includes 10 species of marsupials, 15 rodents, 20 carnivores, eight ungulates and six armadillos. Species richness averaged 13 species (±6.07 SD) per site. Only six species occurred in more than 50% of the sites: the domestic dog Canis familiaris, crab-eating fox Cerdocyon thous, tayra Eira barbara, south American coati Nasua nasua, crab-eating raccoon Procyon cancrivorus and the nine-banded armadillo Dasypus novemcinctus. The information contained in this dataset can be used to understand macroecological patterns of biodiversity, community, and population structure, but also to evaluate the ecological consequences of fragmentation, defaunation, and trophic interactions.

Response to Comment on “Using ecological thresholds to evaluate the costs and benefits of set-asides in a biodiversity hotspot”

Finney claims that we did not include transaction costs while assessing the economic costs of a set-aside program in Brazil and that accounting for them could potentially render large payments for environmental services (PES) projects unfeasible. We agree with the need for a better understanding of transaction costs but provide evidence that they do not alter the feasibility of the set-aside scheme we proposed.