Effects of the control of an invasive tree on the structure of a plant-frugivore network.

Invasive non-native species are one of the main causes of degradation of ecosystems worldwide. The control of invasive species is key to reducing threats to ecosystem viability in the long term. Observations of structural changes in ecological interaction networks following invasive species suppression can be useful to monitor the success of ecological restoration initiatives. We evaluated the structure of plant-bird frugivory interaction networks in a plant community invaded by the guava tree (Psidium guajava L.) by comparing network metrics before and after control actions. Psidium guajava was relevant in all metrics for the unmanaged network in this study, with high degree centrality and high nestedness contribution. Based on the asymmetry of species interactions, we found that birds were highly dependent on the invasive plant before suppression. Once P. guajava trees were eliminated, bird and plant species richness, total number of interactions, and modularity increased, whereas nestedness and interaction strength asymmetry decreased. The diet of the bird community became more diversified once P. guajava was no longer available and relevant species roles in community structure emerged. Our results corroborate the fact that ecological restoration interventions should include the control of non-native plant species that attract frugivorous animals in order to diversify plant-frugivore interactions and thus maintain biodiversity in natural ecosystems.

Contributions of human cultures to biodiversity and ecosystem conservation.

The expansion of globalized industrial societies is causing global warming, ecosystem degradation, and species and language extinctions worldwide. Mainstream conservation efforts still focus on nature protection strategies to revert this crisis, often overlooking the essential roles of Indigenous Peoples and Local Communities (IP&LC) in protecting biodiversity and ecosystems globally. Here we assess the scientific literature to identify relationships between biodiversity (including ecosystem diversity) and cultural diversity, and investigate how these connections may affect conservation outcomes in tropical lowland South America. Our assessment reveals a network of interactions and feedbacks between biodiversity and diverse IP&LC, suggesting interconnectedness and interdependencies from which multiple benefits to nature and societies emerge. We illustrate our findings with five case studies of successful conservation models, described as consolidated or promising 'social-ecological hope spots', that show how engagement with IP&LC of various cultures may be the best hope for biodiversity and ecosystem conservation, particularly when aligned with science and technology. In light of these five inspiring cases, we argue that conservation science and policies need to recognize that protecting and promoting both biological and cultural diversities can provide additional co-benefits and solutions to maintain ecosystems resilient in the face of global changes.

Yams (Dioscorea spp.) in shellmounds and swiddens: ancient history in Babitonga Bay, Santa Catarina State, southern Brazil.

BACKGROUND: In Babitonga Bay, southern Brazil, records of yam consumption exist among shellmound builders from at least 4000 years ago. Shellmounds (sambaquis) are anthropogenic structures in the form of mounds with layers of shells associated with other faunal remains, as well as with charcoal, artefacts and burial. Larger sambaquis are considered to be funerary monuments. The indigenous Jê and Guarani people also lived in the region before the European invasion and cultivated yams. Currently, exotic and domesticated yams are cultivated in the region by farmers. Our aim is to describe the long-term history between the people and Dioscorea in the Babitonga Bay region based on its consumption and occurrence in shellmounds and swiddens. METHODS: Surveys of Dioscorea spp. and host were carried out in the vegetation of shellmounds and in the surrounding area using visual detection through intensive searches in transects using the walking method. The survey of Dioscorea species used and cultivated in the precolonial, colonial and current periods was carried out based on the literature. In the present study, only Dioscorea trifida cultivations were recorded. RESULTS: Dioscorea cayennensis, Dioscorea chondrocarpa, Dioscorea dodecaneura, Dioscorea laxiflora, Dioscorea olfersiana, and Dioscorea scabra, all recorded in associated vegetation of shellmounds, in different combinations of the species. In swiddens, D. trifida is most common, followed by Dioscorea alata and, to a lesser extent, Dioscorea bulbifera and D. cayennensis. Records of food use prevail, but they are used as medicinal plants. Yams are integrated on anthropogenic soils of shellmounds and in swiddens in monoculture systems or in intercropping with Zea mays or Colocasia esculenta. The presence of exotic food trees and D. cayennensis in some shellmounds indicates the influence of colonizers on the composition of the vegetation. In sambaquis, there are overlapping processes of construction of cultural niches by different human groups at different times. CONCLUSIONS: The sambaquis and the associated vegetation and swiddens form part of a domesticated landscape. The native species of Dioscorea recorded in shellmounds and surrounding vegetation do not depend on human action to perpetuate themselves in the environment. However, this does not rule out human influence in the past, but it does not indicate horticulture among the Sambaquianos. Greater investment in genetic, archaeobotanical and ethnobotanical research can contribute to a better understanding of the relationship between people and yams over thousands of years.

Correction: Pre-colonial Amerindian legacies in forest composition of southern Brazil.

[This corrects the article DOI: 10.1371/journal.pone.0235819.].

Pre-colonial Amerindian legacies in forest composition of southern Brazil.

Past human societies have left persistent marks on forests worldwide. However, the degree to which pre-colonial Amerindian societies have affected forest structure is still not fully understood, especially in southern Brazil. This study investigated the influence of two distinct Amerindian groups (Southern-Jê and Guarani) over tree composition of forest fragments in the State of Santa Catarina. Vegetation data was obtained from the Santa Catarina Forest and Floristic Inventory (SCFFI): a statewide systematic vegetation sampling project. Archaeological data was collated from literature reviews as well as existing databases for archaeological sites occupied by Guarani and Southern-Jê groups. Using these sites of known Amerindian occupation, and corresponding environmental variables, ecological niche models were developed for each Amerindian group, predicting potential archaeological sites occupied by these groups across southern Brazil. Maps of these potential occupation sites of pre-colonial Amerindian groups were compared with 417 corresponding floristic inventory plots. Redundancy analysis (RDA) was used to identify floristic composition patterns linked to areas with a high probability of Southern-Jê or Guarani presence. Southern-Jê and Guarani pre-colonial occupations overlapped near main rivers; however, Southern-Jê groups generally occupied elevated areas whereas Guarani occupied mostly coastal areas. We observed differences in forest composition associated with the predicted occurrence of these pre-colonial Amerindian groups. Based on these results, we argue there is a relationship between tree species distribution and pre-colonial human occupation by these two Amerindian groups.

Good times, bad times: Resource pulses influence mammal diversity in meridional Brazilian highlands.

Understanding spatiotemporal patterns of species distributions and their determinants is paramount in ecology. Here, we explore the relationship between the diversity of surviving mammals and two of the main alimentary resources (araucaria seeds and feijoa fruits) across the Araucaria Forest (FOM) in South America. First, we investigated the influence of landscape and environment on the species distribution and pulse of forest productivity. Then, we evaluated how these spatiotemporal pulses in resource availability influence the mammalian diversity. We analyzed the data via diversity descriptors, Morisita index and multiple regressions. Our findings highlighted that climate, tree density, and other environmental variables explained the pulses of productivity. Mammalian diversity of first-order consumers mammals-all those immediately feeding on seeds and fruits-was partially related to resource pulses. Our results revealed that the pulses of forest resources can influence mammal diversity over the years, including delayed responses and asynchronous oscillations. The integrity of vegetal elements of the FOM is key to maintain several mammal-mediated ecological processes. Maintaining the viability of tree populations, encouraging the sustainable use of non-timber resources, and promoting the conservation of the mammalian fauna, which is undergoing an unprecedented diversity crisis worldwide, can help to preserve the remaining ecological processes.

Preventing traditional management can cause grassland loss within 30 years in southern Brazil.

Woody encroachment threatens several ecosystems around the world. In general, management of grasslands includes regulation of fire and grazing regimes. Changes in these two types of disturbances are potential drivers of woody encroachment. Here we assessed how the traditional management carried out by local landholders affects a highland grassland ecosystem in southern Brazil. We hypothesized that grasslands converted to protected areas undergo fast woody encroachment. To reconstruct changes in vegetation, we interviewed former and current landholders and coupled their knowledge with an analysis of aerial and satellite images. During the first 11 years without fire and cattle, woody encroachment in grasslands increased exponentially. Woody encroachment occurred mostly by the replacement of grasslands by shrublands. Meanwhile, grasslands under traditional management remained almost unchanged for the last 40 years. The management of fire by local landholders has been part of their traditional practices for decades. Such management prevents large-scale wildfires and maintains natural highland grasslands. The quick pace of shrub encroachment in such grasslands threatens its exclusive diversity, human well-being and regional cultural heritage. Thus, conservation policies are needed to regulate and instruct about the use of fire as a management tool in highland grasslands of southern Brazil.

ATLANTIC MAMMALS: a data set of assemblages of medium- and large-sized mammals of the Atlantic Forest of South America.

Biodiversity inventories contain important information about species richness, community structure, and composition, and are the first step in developing any conservation and mitigation strategies. The Atlantic Forest of South America is home to around 334 species of small-, medium-, and large-sized mammals, and is currently restricted to less than 12% of its original cover. Here, we present the ATLANTIC MAMMALS, an open data set on information on medium- and large-sized mammal assemblages in the Atlantic Forest of Brazil, Paraguay, and Argentina. A total of 129 studies were compiled, including published and in press peer-reviewed papers, book chapters, theses and unpublished data. We mapped 244 assemblages, eight orders, 63 genera, and 94 species (24 of which are classified as threatened by the IUCN Red List) distributed in 128 protected and 116 unprotected areas. Species richness of the mammalian assemblages varied from 1 to 39 species (mean 15). The most recorded species in the entire biome was Dasypus novemcinctus, followed by Cerdocyon thous and Procyon cancrivorous. These data can be useful in support of macroecological studies and conservation planning strategies. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.