Renato Augusto Ferreira de Lima

Defaunation affects carbon storage in tropical forests

Populations of large frugivores are declining in tropical rainforests with potential consequences for carbon storage and climate. Carbon storage is widely acknowledged as one of the most valuable forest ecosystem services. Deforestation, logging, fragmentation, fire, and climate change have significant effects on tropical carbon stocks; however, an elusive and yet undetected decrease in carbon storage may be due to defaunation of large seed dispersers. Many large tropical trees with sizeable contributions to carbon stock rely on large vertebrates for seed dispersal and regeneration, however many of these frugivores are threatened by hunting, illegal trade, and habitat loss. We used a large data set on tree species composition and abundance, seed, fruit, and carbon-related traits, and plant-animal interactions to estimate the loss of carbon storage capacity of tropical forests in defaunated scenarios. By simulating the local extinction of trees that depend on large frugivores in 31 Atlantic Forest communities, we found that defaunation has the potential to significantly erode carbon storage even when only a small proportion of large-seeded trees are extirpated. Although intergovernmental policies to reduce carbon emissions and reforestation programs have been mostly focused on deforestation, our results demonstrate that defaunation, and the loss of key ecological interactions, also poses a serious risk for the maintenance of tropical forest carbon storage.

Composição, diversidade e distribuição geográfica de plantas vasculares de uma Floresta Ombrófila Densa Atlântica do Sudeste do Brasil

In the Montane and Submontane Rain Forest of the Carlos Botelho State Park - PECB (ca. 37,000 ha) the composition, richness and geographical distribution of native, vascular forest species was evaluated. The analysis of 1143 species of 140 families supported the pattern found for other forests of Eastern Brazil, showing high species richness of Myrtaceae (85 species), Orchidaceae (81), Fabaceae (57), Asteraceae, Melastomataceae (54), Lauraceae (53), Rubiaceae (51), Bromeliaceae (43), Piperaceae (30) and Solanaceae (25), besides ferns (123). The most species-rich genera were Eugenia (34), Ocotea (26), Leandra, Myrcia, Vriesea (18), Piper, Solanum (16), Miconia (14), Mollinedia (13), and Peperomia (12). The richness and composition varied greatly among life forms, as well as the number of families represented in each one of them (only Rubiaceae had species in all life forms, except parasites). Trees had the largest contribution of total richness (39.1%), a value that represented more than 20% of the species listed for the whole Atlantic Forest of Southeastern Brazil. Trees were followed by epiphytes (22.4%), herbs (18.4%), shrubs (10.1%), lianas (9.1%), and parasites (0.9%). The overall richness and composition of life forms was quite close to other neotropical forests (e.g. high contribution of ferns among epiphytes), although some life forms remain undersampled in the PECB (mainly herbs, lianas and epiphytes). The occurrence of species endemic to the Atlantic Forest was pronounced (65%), with a predominance of species restricted to the Southern Atlantic Forest (43%). Pantropical species were rare (2%), being more common among ferns. Myrtaceae and Melastomataceae were the families with greater number and proportion of endemic species.

Flora vascular do Parque Estadual Carlos Botelho, São Paulo, Brasil

Located in the Serra de Paranapiacaba, South of Sao Paulo State, the Carlos Botelho State Park (PECB) shelters more than 37,000 ha of Atlantic Forest in one of the most important and large remnants of this Biome in Brazil. In the Park the Montane and Submontane rain forests are the predominant types of forests. Aiming to organize the available floristic information and to orient future surveys, this study presents the list of native vascular species of the PECB forests. Besides authors´ personal collections, more than 3,900 records since 1967 were compiled. Coming from different sources of information, these records were checked for the presence of botanical synonyms and new combinations. A total of 1,143 species belonging to 528 genera and 140 families were listed (other 63 species were not included because they were non-native or of doubtful occurrence/determination). There was a great richness of Myrtaceae, Orchidaceae, Fabaceae, Asteraceae, Melastomataceae, Lauraceae, Rubiaceae and Bromeliaceae. Although high species richness was found, the richness of herbs, lianas and epiphytes are certainly underestimated and future surveys will add many species to the list presented here. In addition, more than 60 endangered species were found, mainly among the Myrtaceae, Lauraceae and Gesneriaceae families. Therefore, these results put the PECB among the most species-rich conservation units of Sao Paulo state with great relevance to national conservancy of plant diversity.

Repeated disturbances and canopy disturbance regime in a tropical semi-deciduous forest

The canopy disturbance regime and the influence of gap methods on the interpretation of forest structure anddynamicswereevaluatedinatropicalsemi-deciduousforestinsouth-easternBrazil.Weencounteredagapdensity of 11.2 gaps ha −1 and an average size which varied from 121 to 333 m 2 depending on the gap delimitation method considered (minimum gap size was 10 m 2 ). Although average size was slightly higher, the median value obtained (78 m 2 ) was comparable to other tropical forest sites and the gap size-class distribution found supported the pattern described for such forest sites. Among 297 gap makers, snapping and uprooting were the most common modes of disturbance.Thenumberandbasalareaofgapmakersweregoodpredictorsofgapsize.Almost25%ofallgapssuffered fromrepeateddisturbanceeventsthatbroughtaboutlargergapsizes.Suchprocesses,alongwithdelimitationmethods, strongly influenced the estimation of turnover rate and therefore the interpretation of forest dynamics. These results demonstrated the importance of further studies on repeated disturbances, which is often neglected in forest studies.

Estrutura e regeneração de clareiras em florestas pluviais tropicais

This paper presents a critic review of the available knowledge on canopy gap structure and regeneration in Tropical Rain Forests. Separated on different issues such as gap size, type of treefall, physical environment, regeneration sources and ecological groups, each issue is explored in detail through the main studies published. Hence, old issues are discussed and gaps of knowledge are pointed out to enhance and ground future researches. As a result, it was observed that despite of more then three decades of research and several studies involving gap structure and regeneration, the research regarding the theme still has many questions to be answered. It also has limitations linked to the existing plurality of methods and to the difficulty of comparing different forests worldwide. It was concluded that the research involving gap structure and regeneration is on a theoretical refinement phase and, therefore, it is hard to evaluate the real contribution of canopy openings to the understanding of the different forests formations dynamics.

Structure, diversity, and spatial patterns in a permanent plot of a high Restinga forest in Southeastern Brazil

(Structure, composition, and diversity of a high Restinga forest in the Southern Atlantic Forest) We assessed the structure, diversity and distribution of tree species in a 10.24-ha permanent plot of high Restinga forest (HRF) in southeastern Brazil. We sampled 15,040 individuals belonging to 45 families, 87 genera and 116 species (density= 1,468 trees ha -1 , and basal area= 28.0 m 2 ha -1 ). Mean richness was lower than other types of tropical forests and other HRFs that have been less intensively sampled, which is probably due to the younger age and hydromorphy of the soils in the study site. Tree density, basal area, species composition, and diversity all varied considerably depending on the size class considered. The studied plot had a density similar to other tropical forests but with a smaller basal area (fewer individuals > 60 cm in diameter), and higher density of smaller trees. Multi-stemmed individuals were not frequent (11% of the trees), though they were widespread among species (74% of the species). Spatial distribution was predominantly clumped, a pattern common to other types of tropical forests. Besides growing over white-sand soils, the PEIC plot and other white-sand forests of the world also had very similar patterns of community structure, richness and diversity. Therefore, we consider the HRF as a recognizable subtype of white-sand forest.

Canopy gap colonization in the Atlantic Montane Rain Forest

In the Atlantic Montane Rain Forest of South-easter n Brazil, a study was carried out to describe and e canopy gap colonization. Gap composition by herb sp ecies was assessed through their soil coverage and woody species by measuring and identifying all individual s taller than one meter. Gap structure (gap size, n umber and diameter of treefalls), topographic position and su rrounding vegetation were also measured. Two genera of Marantaceae were markedly frequent and abundant ins ide gaps. The more abundant and frequent woody spec ies were shade tolerant. Species-rich families found in side gaps did not differ from the forest as a whole . Results revealed that direct and indirect influences of top ography were important to determine gap composition of woody species. Evidently gap colonization had a considera ble influence of topography and pre-established ind ividuals besides variables of gap structure.

COMPOSIÇÃO E DIVERSIDADE NO CERRADO DO LESTE DE MATO GROSSO DO SUL, BRASIL

RESUMO – Neste estudo, avaliaram-se a composicao e diversidade no Cerrado em tres areas do Leste de Mato Grosso do Sul, uma das regioes mais ameacadas e menos estudadas do Cerrado brasileiro. Para tanto, levantaram-se as especies vasculares em trilhas percorridas em diferentes fisionomias desse bioma, com enfoque especial para as especies arbustivas e arboreas. Adicionalmente, nas areas de Cerrado sensu stricto foram instaladas 30 parcelas de 10 x 3 m, nas quais foram amostrados apenas individuos lenhosos > 1 m de altura. No geral, foram levantadas 220 especies, 150 generos e 65 familias de diferentes formas de vida, incluindo especies consideradas raras nos Cerrados brasileiros e possiveis novas ocorrencias nos Cerrados de Mato Grosso do Sul. A riqueza de especies arbustivas e arboreas no Cerrado sensu stricto foi alta (79-101 especies por area). Houve baixa similaridade floristica entre as areas estudadas, de modo que apenas 50 especies foram comuns a todas elas. O estudo da vegetacao lenhosa por meio de parcelas (total de 651 individuos e 105 especies) revelou uma diferenca na riqueza media, diversidade (indice de Shannon) e dominância (Berger-Parker) entre as areas estudadas. Adicionalmente, a densidade relativa das especies e a composicao floristica foram bastante variaveis entre as areas estudadas (similaridade entre 0,42 e 0,53). Tais resultados colocam as areas estudadas entre as mais ricas areas de Cerrado sensu stricto do Brasil, mostrando que areas marginais de Cerrado podem ser tao ricas quanto suas areas centrais, mesmo que atraves da contribuicao de elementos floristicos de outras formacoes florestais. Os resultados reforcam ainda a existencia de elevada heterogeneidade floristica no Cerrado, mesmo em distâncias relativamente curtas ( 60 km), que pode ser desencadeada por diferencas entre fragmentos em relacao a caracteristica de solo, historico de perturbacao e proximidade de outras formacoes vegetais.

Estimating interaction credit for trophic rewilding in tropical forests

Trophic rewilding has been suggested as a restoration tool to restore ecological interactions and reverse defaunation and its cascading effects on ecosystem functioning. One of the ecological processes that has been jeopardized by defaunation is animal-mediated seed dispersal. Here, we propose an approach that combines joint species distribution models with occurrence data and species interaction records to quantify the potential to restore seed-dispersal interactions through rewilding and apply it to the Atlantic Forest, a global biodiversity hotspot. Using this approach, we identify areas that should benefit the most from trophic rewilding and candidate species that could contribute to cash the credit of seed-dispersal interactions in a given site. We found that sites within large fragments bearing a great diversity of trees may have about 20 times as many interactions to be cashed through rewilding as small fragments in regions where deforestation has been pervasive. We also ranked mammal and bird species according to their potential to restore seed-dispersal interactions if reintroduced while considering the biome as a whole and at finer scales. The suggested approach can aid future conservation efforts in rewilding projects in defaunated tropical rainforests. This article is part of the theme issue ‘Trophic rewilding: consequences for ecosystems under global change’.

How do size distributions relate to concurrently measured demographic rates? Evidence from over 150 tree species in Panama

In stable populations with constant demographic rates, size distributions reflect size-dependent patterns of growth and mortality. However, population growth can also affect size distributions, which may not be aligned with current growth and mortality. Using 25 y of demographic data from the 50-ha Barro Colorado Island plot, we examined how interspecific variation in diameter distributions of over 150 tropical trees relates to growth–diameter and mortality–diameter curves and to population growth rates. Diameter distributions were more skewed in species with faster increases/slower decreases in absolute growth and mortality with diameter and higher population growth rates. The strongest predictor of the diameter distribution shape was the exponent governing the scaling of growth with diameter (partial R2 = 0.20–0.34), which differed among growth forms, indicating a role of life history variation. However, interspecific variation in diameter distributions was also significantly related to population growth rates (partial R2 = 0.03–0.23), reinforcing that many populations are not at equilibrium. Consequently, although fitted size distribution parameters were positively related to theoretical predictions based on current size-dependent growth and mortality, there was considerable deviation. These analyses show that temporally variable demographic rates, probably related to cyclic climate variation, are important influences on forest structure.