1. Tropical forests hold some of the world's most diverse communities of plants.Many populations of large-bodied herbivores are threatened in these systems, yet their ecological functions and contribution towards the maintenance of high levels of plant diversity are poorly known. The impact of these herbivores on plant communities through antagonistic seed and seedling predation has received much attention, whilst their relevance as seed dispersal agents has been largely overlooked in experimental studies.2. Here, we tested how two key and functionally distinct large generalist mammalian herbivore species (the tapir Tapirus terrestris -a solitary browser and generalist seed disperser, and the white-lipped peccary Tayassu pecari -a group-living generalist seed/seedling predator) affect spatiotemporal patterns of diversity of seedling communities in tropical forests. We conducted a long-term multi-region landscape-scale exclusion experiment across four regions of the Atlantic forest of Brazil, representing a functional gradient of defaunation where these species were either present and absent in isolation and in combination. 3.Our results indicate that mammalian herbivores have a substantial role in regulating beta diversity in space and time. Seedling recruitment was strongly limited by the presence of the seed/seedling predator species (the peccary), but the presence of the browser and seed disperser (the tapir) had null net effects. Alpha diversity of seedlings at the community level did not respond to large herbivore exclusion at any region, whereas beta diversity decreased only where both herbivores were simultaneously excluded. Surprisingly, the synergic positive effect of both herbivore types on beta diversity was linked to increased evenness amongst dominant plant species, and a simultaneous decrease in alpha diversity of rare species.4. Synthesis. Together, these results challenge the common perception that large tropical forest herbivores maintain tropical forest diversity through antagonistic interactions, suggesting instead a synergistic effect of antagonistic predation and mutualistic seed dispersal on regional compositional diversity and local community 280 | Journal of Ecology VILLAR et AL.
1. Tropical rainforests are populated by large frugivores that feed upon fruit-producing woody species, yet their role in regulating the cycle of globally important biogeochemical elements such as nitrogen is still unknown. This is particularly relevant because tropical forests play a prominent role in the nitrogen cycle and are becoming rapidly defaunated. Furthermore, frugivory is not considered in current plant-large herbivore-nutrient cycling frameworks exclusively focused on grazers and browsers. 2. Here we used a long-term replicated paired control-exclusion experiment in the Atlantic Forest of Brazil, where peccaries and tapirs are the largest native frugivores, to examine the impact of large ground-dwelling frugivores on modulating soil nitrogen cycling, considering their effects across a gradient of abundance of a hyper-dominant palm. 3. We found that both large frugivores and dominant palms play a substantial role in modulating ammonium availability and nitrification rates. Large frugivores increased ammonium by 95%, which also increased additively with palm abundance. Nitrification rates increased with palm abundance in the presence of large frugivores, but not on exclosure plots. Large frugivores also stimulated the regulation of the functions of soil-nitrifying microorganisms, and modulated the landscapescale variance in nitrogen availability. Such joint effects of large frugivores and palms are consistent with the notion of 'fruiting lawns'. 4. Our study indicates that frugivory plays a pivotal role in zoogeochemistry in tropical forests by regulating and structuring the nitrogen cycle, urging to accommodate frugivory in plant-large herbivore-nutrient cycling frameworks. It also indicates that defaunation, deforestation and illegal palm and timber harvesting seriously affect nitrogen cycling in tropical forests, that play a prominent role in the global cycle of this nutrient.
A floristic survey was carried out in the Parque Estadual Intervales (PEI), Base Saibadela (24°14'08"S, 48°04'42"W), São Paulo State, southeastern Brazil. The PEI reserve, along with other conservation unities, compose the largest preserved area of Atlantic rain forest remained today. Monthly collections of botanical material were conducted from 1993 to 1997 and 1999 to 2002, mainly along trails and plots inside the forest. A total of 436 plant species, 74 monocots and 362 eudicotiledons (here including the parafiletic groups) were sampled, including five new species. The richness of the flora at Base Saibadela was similar to that observed for other Atlantic forest sites. The trees represented 57.1% of the species, followed by epiphytes (12.6%), lianas (10.3%), herbs (9.4%) and shrubs (9.2%). The families Myrtaceae (55), Rubiaceae (32), Fabaceae (25), Melastomataceae (23), Araceae (20), Lauraceae Orchidaceae and Solanaceae (14 species each one) showed the highest number of species. The genus Eugenia with 25 species was richest genera surveyed. Seed dispersal by animals was expressively higher than other modes, which comprises 80.7% of the 419 species where seed dispersal mode was determined, confirming the pattern found for other tropical wet forests, and highlighting the importance of plant-animal interactions to the Atlantic forest.Key words: Biodiversity, tropical rainforest, Atlantic forest, floristic inventory, dispersion syndromes. ResumoFoi realizado um levantamento florístico no Parque Estadual Intervales, Base Saibadela (24°14'08"S, 48°04'42"W), que faz parte da maior área contínua de Floresta Atlântica brasileira remanescente, situada no sul do Estado de São Paulo. Durante os anos de 1993-1997 e 1999-2002 foram feitas coletas mensais de material botânico, principalmente ao longo de trilhas e parcelas no interior da floresta. Foi registrado um total de 436 espécies vegetais, 74 monocotiledôneas (incluindo os grupos parafiléticos), sendo descobertas cinco espécies novas. A riqueza florística na Base Saibadela foi compatível com a riqueza florística encontrada em outras localidades de Floresta Atlântica. O hábito arbóreo representou 57,1% das espécies, seguido de epífitas (12,6%), lianas (10,3%), herbáceas (9,4%) e arbustos (9,2%). As famílias Myrtaceae (55), Rubiaceae (32), Fabaceae (25), Melastomataceae (23), Araceae (20), Lauraceae, Orchidaceae e Solanaceae (14 espécies cada) apresentaram a maior riqueza florística. O gênero Eugenia apresentou 25 espécies, destacando-se dos demais gêneros encontrados. A dispersão por animais foi expressivamente maior do que os demais modos, representando 80,7% das 419 espécies cuja síndrome foi determinada, confirmando o padrão encontrado para outras florestas tropicais úmidas e ressaltando a importância da fauna na Floresta Atlântica. Palavras-chave:
Epiphytes are hyper‐diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non‐vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer‐reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non‐vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non‐vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events.
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