Lowland Rainforest Research Articles

Phosphorus scarcity contributes to nitrogen limitation in lowland tropical rainforests.

There is increasing evidence to suggest that soil nutrient availability can limit the carbon sink capacity of forests, a particularly relevant issue considering today's changing climate. This question is especially important in the tropics, where most part of the Earth's plant biomass is stored. To assess whether tropical forest growth is limited by soil nutrients and to explore N and P limitations, we analyzed stem growth and foliar elemental composition of the five stem widest trees per plot at two sites in French Guiana after 3 years of nitrogen (N), phosphorus (P), and N + P addition. We also compared the results between potential N-fixer and non-N-fixer species. We found a positive effect of N fertilization on stem growth and foliar N, as well as a positive effect of P fertilization on stem growth, foliar N, and foliar P. Potential N-fixing species had greater stem growth, greater foliar N, and greater foliar P concentrations than non-N-fixers. In terms of growth, there was a negative interaction between N-fixer status, N + P, and P fertilization, but no interaction with N fertilization. Because N-fixing plants do not show to be completely N saturated, we do not anticipate N providing from N-fixing plants would supply non-N-fixers. Although the soil-age hypothesis only anticipates P limitation in highly weathered systems, our results for stem growth and foliar elemental composition indicate the existence of considerable N and P co-limitation, which is alleviated in N-fixing plants. The evidence suggests that certain mechanisms invest in N to obtain the scarce P through soil phosphatases, which potentially contributes to the N limitation detected by this study.

The genus Cultrobates (Acari: Oribatida: Ceratokalummidae) in the Galapagos Islands and Central America

The species Cultrobates heterodactylus Willmann, 1930 is known from Central America and has erroneously been reported from the Galapagos archipelago. A comparison with findings of this species from Panama has highlighted morphological differences between the specimens from Galapagos and C. heterodactylus. Herein, two new species from Galapagos, Cultrobates ermilovi n. sp. and Cultrobates subiasi n. sp. are described and illustrated. Also, differences in colonization of different islands as well as preferences in occupation of different habitats of the two species in Galapagos were noted, whereby C. subiasi was found almost exclusively in epiphytic habitats, predominantly in moss, and C. ermilovi occurs in various microhabitats in ground litter. Cultrobates heterodactylus occurs in Panama in lowland tropical rainforests, mainly in moist forest floor and litter in epiphytic bromeliads. Additional taxonomical remarks on C. heterodactylus are presented. Corrections to previous distribution data are given.

First record of the parasitoid wasp Ixodiphagus hookeri (Hymenoptera: Encyrtidae) infesting the tick Amblyomma nodosum (Acari: Ixodidae)

Ticks (Ixodida) are ecologically important ectoparasites that may impact human health and economic activities. Parasitoid wasps are natural enemies of ticks and a potential option for its biological control. In the present study, we recorded parasitism of the nymphs of the tick Amblyomma nodosum by the parasitoid wasp Ixodiphagus hookeri. The ticks, in turn, were parasitizing white-bearded manakins, Manacus manacus (Passeriformes: Pipridae) in the União Biological Reserve, one of the last major remnants of lowland rainforest in Rio de Janeiro state, southeastern Brazil. During the collection of ectoparasites from two manakins in this reserve, 20-30 parasitoid wasps hatched spontaneously from two of the ticks collected. The species of the tick nymphs and adult wasps were identified using morphological traits and molecular analyses. This record is the first documented case of I. hookeri parasitizing A. nodosum and the first time that parasitoid wasps have been found in ticks parasitizing birds in Brazil. This is also the first record of Ixodiphagus from southeastern Brazil in more than a century, with the only other record dating back to 1914. The record presented here provides valuable new information on the biology of this tick and its parasitoids, and new insights into this interspecific interaction. Further research on these vertebrate-tick-wasp interactions will be necessary to better understand the respective roles of the organisms involved in these processes.

Parallel evolution and cryptic diversification in a common and widespread Amazonian tree, Protium subserratum.

The lowland Amazon rainforest houses some of the greatest tree diversity on Earth. While the vast majority of these species are rare, a small number are common and widespread and thus considered to play a disproportionate role in many of the global ecosystem services provided by the Amazon. However, the extent to which dominant Amazonian tree species actually include multiple clades, each on their own unique evolutionary trajectory, is unknown. Here we investigate the extent to which lineage divergence may be occurring within Protium subserratum (Burseraceae), a common and widespread tree species that is monophyletic with populations exhibiting genotypic and phenotypic differences associated with soil and geography. Utilizing a combination of phylogenomic and population genomic methods with sampling from across the range, we found that P.subserratum contains at least eight distinct clades. Specialization onto white-sand soils has evolved independently at least twice within the species; however, phenotype is not correlated with soil type. Finally, cryptic diversity at the base of the Andes is associated with elevational shifts. Together these results lend support to the hypothesis that common and widespread Amazon tree species may not represent evolutionary cohesive units. Instead, these dominant species may more commonly represent species complexes, undergoing evolutionary transitions on a trajectory to become multiple range-restricted, specialist species.

Seasonal Patterns and Species Variability in the Leaf Traits of Dominant Plants in the Tropical Rainforests of Hainan Island, China

The leaf traits measured in multiple species are known to vary between seasons, but there is a knowledge gap relating to the seasonal variability and environmental adaptation of plants in tropical rainforests. To investigate the dynamics of the functional traits of dominant species in tropical rainforests and the differences in their adaptation strategies to seasonal drought, the results of this study can provide a scientific basis for tropical rainforest conservation resource protection. Six dominant species, including three trees (Hopea reticulata, Vatica mangachapoi, and Diospyros chunii) and three vine plants (Ancistrocladus tectorius, Phanera khasiana, and Uvaria sanyaensis), in tropical lowland rainforest in the Ganzaling Nature Reserve of Hainan province were selected as study objectives. The key leaf traits were studied using the paraffin section method, leaf epidermis segregation method, and Li-6400 portable photosynthesis system in June, September, December, 2019, and March, 2020. Results showed that significant differences in photosynthetic physiology and morphological and structural parameters among species, as well as seasonal variability, were observed in leaf photosynthetic physiology, but not in leaf morphological or structural parameters. A phenotypic plasticity index (PPI) analysis revealed more variability in leaf photosynthetic physiology (Average PPI = 0.37) than in leaf anatomical structure and morphology (Average PPI = 0.26), suggesting that they adapt to seasonal changes primarily by regulating photosynthetic physiological parameters rather than leaf morphology or anatomical structure. The dominant trees were found to have higher water use efficiency, leaf dry-matter content, and smaller leaf areas compared to vine plants. This indicates that the dominant tree species depend on high water use efficiency and leaf morphological characteristics to adapt to seasonal changes. The majority of leaf anatomical structure parameters associated with drought tolerance were higher in the three dominant vine species, indicating that the dominant vine species adapted to drought stress primarily by altering the leaf anatomical structure This study provides information on how tropical rainforest plants adapt to seasonal drought as well as supporting the protection of tropical rainforest ecosystems.

A New Species of Small Green Treefrog (Pelodryadidae: Litoria) from the Lakekamu Basin in Southern Papua New Guinea

We describe a new species of very small (male body length 22.0–22.8 mm), green treefrog in the pelodryadid genus Litoria Tschudi from lowland rainforest on the southern margin of Papua New Guinea's central cordillera. The new species is morphologically most similar to Litoria leucova, a small green treefrog known only from the north-flowing Sepik River catchment in western Papua New Guinea. It differs from that species by having longer limbs (TL/SVL 0.56–0.60 vs. 0.53–0.55), a poorly defined (vs. prominent) tympanum, in having a distinct lemon yellow mid-lateral line, and in its unique advertisement call comprising a slowly repeated series of short clicks followed by a discrete group of pulses produced rapidly but with highly variable inter-pulse intervals. Although genetic data are not available, the new species' association with a fast-flowing rocky stream suggests that its relationships may lie with other torrent-dwelling Litoria species.

Variations of arbuscular mycorrhizal fungi following succession stages in a tropical lowland rainforest ecosystem of South China

IntroductionThe grasslands in the Nature Reserve of Ganshenling, in the south of Hainan Island, were first formed after deforestation disturbance before a natural restoration of shrubs and secondary forests. However, the stages of grassland and shrubs in some parts of Ganshenling regions could not be naturally restored to secondary forests. In addition, the forest form of the secondary forest after 40 years (40a) of succession was similar to that of the secondary forest of 60 years (60a). However, it was not known whether the microorganisms recovered to the level of the secondary forest of 60a. Arbuscular mycorrhizal fungi (AMF) are plant root symbionts that can improve the nitrogen and phosphorus absorption of plants and play a key role in secondary forest succession. An understanding of the essential role of soil AMF in secondary forest succession of tropical rainforest in Ganshenling regions is still limited.MethodsTherefore, the soil of 0–10 cm was collected with the help of a 5-point sampling method in grassland, shrubs, and second tropical lowland rainforest of 40a and 60a. We studied community changes in AMF with the succession and explored the impacts of soil physicochemical properties on soil AMF.ResultsOur findings were as follows: (1) Different successional stages showed divergent effects on soil AMF communities. (2) After 40a recovery, the alpha-diversity indices of AMF recovered to the level of secondary forest of 60a, but the similarity of soil AMF communities only recovered to 25.3%. (3) Species richness of common species, rare species, and all the species of AMF showed a significantly positive correlation with soil nitrogen. (4) OTU10; OTU6, OTU9, and OTU141; OTU3 and OTU38; and OTU2, OTU15, OTU23, and OTU197 were significantly unique AMF for grasslands, shrubs, and secondary forests of 40a and 60a, respectively. (5) The phylogenetic tree and the heatmap of AMF showed that the OTUs in grasslands and shrubs were in contrast to the OTUs in secondary forests of 40a and 60a.DiscussionWe concluded that the succession of a secondary forest after deforestation disturbance was probably limited by its AMF community.

Indications of an Achaea sp. caterpillar outbreak disrupting fruiting of an ectomycorrhizal tropical tree in Central African rainforest

Background and aims – Where one or several tree species come to dominate patches of tropical forest, as many masting ectomycorrhizal legumes do in Central Africa, ecological theory predicts they may be prone to herbivory, which might alter their reproductive output. This was indirectly investigated in lowland rainforest in Cameroon for Tetraberlinia korupensis, whose crowns were attacked in 2008 by an outbreaking black caterpillar—identified as an Achaea sp., probably A. catocaloides—in Korup National Park. Material and methods – Field-collected data on tree-level seed and fruit (pod) production of T. korupensis in its 2008 masting event were compared with that of its two co-dominant neighbours (T. bifoliolata, Microberlinia bisulcata), whose populations masted in 2007 (and 2010). To do this, bivariate regression models (linear, polynomial, ZiG [zero-inflated gamma model]), contingency table analysis, and non-parametric measures of dispersion were used. Key results – Assuming T. korupensis is prone to Achaea caterpillar attacks, empirical data support the hypothesized lower proportion of adults participating in its masting (54% in 2008) than for either masting population of M. bisulcata (98% in 2007, 89% in 2010) or T. bifoliolata (96% in 2007, 78% in 2010). These fruiting T. korupensis trees were about one-third larger in stem diameter than conspecific non-fruiters and produced as many pods and seeds per capita as T. bifoliolata. However, regressions only modestly support the hypothesis that the positive tree size–fecundity relationship for T. korupensis was weaker (i.e. lower adj. R2) than for M. bisulcata (whose leaves are morphologically similar) or T. bifoliolata, with mostly similar dispersion about the median among these species. Conclusion – Altogether, the findings suggest a role for tolerance in nutrient-poor forests. It is postulated that instead of conferring resistance to herbivores, the ectomycorrhizas associated with these trees may enable them to more quickly recover from potential yet unpredictable insect outbreaks.

Environmental factors driving the succession and differentiation of ecological strategy spectrum in tropical lowland rain forest

We aimed to determine the environmental driving factors underpinning successional changes in a tropical lowland rain forest in Hainan. Using hectare scale plots, we evaluated woody plant community composition and collected a variety of environmental variables. We found that the ecological strategy spectrum of communities in the four succession stages differentiated along the C-S axis, but no major communities were found in the R strategy group. The spectrum of ecological strategy of different communities is significantly different with succession, among which C strategy group is on the rise, S strategy group is on the decline, and the intermediate (INT) group strategy is on the rise after the first decline. For the C strategy group, population density and canopy openness explain most of the differences. The S strategy group are explained by slope and population density, while the first two explanatory factors of intermediate strategy group differences are slope and soil total potassium content. The change of plant ecological strategy is the result of comprehensive action of biotic factors, topographic factors and soil factors, among which biotic factors play a leading role.

The spatial propagation and increasing dominance of Gilbertiodendron dewevrei (Fabaceae) in the eastern Congo basin.

Though substantial research has been conducted on possible historical, physiological, and symbiotic mechanisms that permit monodominance to occur within tropical lowland rainforests, less is known about the successional rates at which monodominance exerts itself on surrounding forest structures. Here we extend efforts to evaluate the longitudinal dynamics of Gilbertiodendron dewevrei-dominated forest in Central Africa by considering this species' spatial dynamics. Using three 10-ha censused field plots measured across three time periods, we present the first quantitative estimates of the spatial propagation of Gilbertiodendron into adjacent mixed species forest. Using three analytical strategies, we demonstrate that Gilbertiodendron is increasing in dominance and that monodominant forest patches are expanding into the surrounding forest at a statistically significant rate. The rates of successional advance vary by patch and direction, but average 0.31 m year-1, with speeds greatest in the direction of the prevailing winds. We show that the advancement of Gilbertiodendron is significantly slower than documented rates from other forest ecotones across Central Africa. When paired with stress tolerance traits and ectomycorrhizal associations, these findings help to clarify the means by which Gilbertiodendron dewevrei gains dominance in otherwise species-diverse regions.

Litterfall Production and Litter Decomposition Experiments: In Situ Datasets of Nutrient Fluxes in Two Bornean Lowland Rain Forests Associated with Acacia Invasion

It is increasingly recognized that invasion by alien plant species such as Acacia spp. can impact tropical forest ecosystems, although quantifications of nutrient fluxes for invaded lowland tropical rain forests in aseasonal climates remain understudied. This paper describes the methodology and presents data collected during a year-long study of litterfall production and leaf litter decomposition rates in two distinct tropical lowland forests in Borneo affected by Acacia invasion. The study is the first to present a comprehensive dataset on the impacts of invasive Acacia species on Bornean forests and can be further used for future research to assess the long-term impact of Acacia invasion in these forest ecosystems. Extensive studies of nutrient cycling processes in aseasonal tropical lowland rainforests occurring on different soil types remain limited. Therefore, this dataset improves understanding of nutrient cycling and ecosystem processes in tropical forests and can be utilized by the wider scientific community to examine ecosystem responses in tropical forests.

Avifauna recovers faster in areas less accessible to trapping in regenerating tropical forests

Tropical forest restoration stands to deliver important conservation gains, particularly in lowland Southeast Asia, which has suffered some of the world's highest rates of recent forest loss and degradation. This promise, however, depends on the extent to which biodiversity at forest restoration sites continues to be exposed to threats. A key knowledge gap concerns the extent to which biodiversity recovery in naturally regenerating tropical forests is impacted by trapping for the multi-million-dollar wildlife trade. Here, we use a repeated survey dataset to quantify rates of avian community recovery under forest regeneration, at a flagship restoration site in the lowland rainforests of Sumatra, Indonesia. We show that over a decade, forest regeneration was associated with significant abundance increases for 43.8 % of bird species. However, the apparent negative impacts of trade-driven trapping on avian populations also intensified: the proportion of species dependent on very remote forests increased from 5.4 % to 16.2 %. Moreover, the overall accessibility of the forest increased. We found that 14 % of species did not recover as fast as predicted based on the observed forest regeneration over the study period. We found trapping to disproportionately impact species targeted for trade: compared to opportunistically trapped species, twice more species showed increased abundance only in very remote forests. Our results highlight the potential for rapid avifaunal recovery in regenerating tropical forests, but also emphasize the urgency of tackling the serious threat of wildlife trade to Southeast Asia's biodiversity.

Ecological niches of epiphyllous bryophytes along Afrotropical elevation gradient

Understanding multiple environmental drivers governing tropical organisms' distribution and ecological niches is crucial for predicting their responses to ongoing rapid deforestation. While macroclimatic effects via energy and water availability are well predicted, less is known about locally modulating factors such as canopy structure, light and edaphic conditions. Here we show that minimum temperatures and ambient humidity drive the abundance and richness of leaf‐inhabiting epiphyllous bryophytes across 4‐km elevation gradient on Mount Cameroon, West Africa, separating epiphyll‐rich rainforests (0–2200 m a.s.l.) from epihyll‐poor fire‐driven afromontane savanna (2300–4000 m a.s.l.). However, local factors contribute more than half to the total abundance and richness variation, either directly (light) or indirectly (edaphic conditions) via their effects on host plant composition. The most abundant epiphyllous communities occur in vertically stratified upland rainforests between 600 and 1100 m elevation, where N‐fixing tree legumes dominate. Their canopy is relatively sparse, due to nutrient‐poor soils leached by high rainfall, leaving room for the development of diverse subcanopy tree and understory shrub and herb layers with epiphyll‐rich communities. Vertically homogenous lowland rainforests on fertile soils below 500 m, with dense overstory and shaded and species‐poor understory, have less developed epiphylls, as do seasonally dry montane forests between 2000 and 2300 m, or elephant fragmented forests between 1200 and 1600 m. We conclude that high temperature and humidity together with a vertically stratified canopy support epiphylls, whereas precipitation seasonality, disturbed vegetation with unstable microclimate, or dense, unstratified canopy discourage the development of epiphyllous communities. Our study illustrates that ecological niches of epiphyllous bryophytes are shaped by a complex interplay of multiple drivers, knowledge of which is essential for more realistic predictions of the impacts of current accelerated habitat loss on species distribution and diversity changes in the tropics.

Bryophytes of the Republic of Equatorial Guinea (West Central Africa) VII. New records and range extensions of liverworts from Río Muni

Río Muni (Muni region) is the continental and largest part of the Republic of Equatorial Guinea, extending over 26000 of its 28000 km2, placed between Cameroon and Gabon. The territory is quite homogeneous from a vegetation point of view: 99% of the area is covered by forest, around 20% of which is still primary. The lowland rainforest is most typical; only on the most mountainous areas is a less dense submontane forest developed. The current knowledge of the Río Muni bryoflora is still poor: 181 taxa (107 liverworts and 74 mosses) have been recorded so far. Data on 19 liverwort species in the families Cephaloziellaceae, Frullaniaceae, Lejeuneaceae, Lepidoziaceae, Metzgeriaceae and Porellaceae are offered. Six of them are new additions for the country of Equatorial Guinea, and seven are new for the Muni region (Río Muni). For each species, geographical distribution, altitudinal range, ecological information and accompanying bryophyte species are given.

Post Debarking Response of <i>Prunus africana</i> (Hook. F) Kalkman (<i>Rosaceae</i>) Trees at Two Exploitation Sites in North Kivu (Eastern Democratic Republic of Congo)

Prunus africana is a species of great economic, medicinal and ecological importance. Due to its multiple uses, unsustainable exploitation methods and low regeneration capacity in tropical rainforests, this species is threatened with extinction. Present and exploited in the eastern part of DR Congo, knowledge of the dynamics of post-bark regeneration of Prunus africana remains fragmentary and poorly known. In North Kivu province, this species thrives in both afromontane forest and lowland tropical rainforest habitats. In order to contribute to the rational and sustainable exploitation of Prunus africana in this province, this paper was carried out with the objective of contributing to the knowledge of the dynamics of the regeneration of post-harvest bark of Prunus africana in two exploitation sites (low and high altitude). To achieve this objective, the inventory was conducted on 16 plots of 25 hectares each, with 8 plots per site. Dendrometric parameters (diameter at breast height (DBH), total tree height) and tree growth and regeneration parameters, i.e., stem bark thickness of the unharvested and harvested portions of the trees (bark reconstitution) were measured. A total of 716 barked stems of Prunus africana in 2016 in 25 hectares constituted the study sample. Results show that sites do not influence diameter at breast height of P. africana trees (p > 0.05) or total tree height. The bark diameter of harvested trees and the bark diameter of unharvested trees varied significantly by site (p 0.05). In contrast, the annual growth rate of bark differed with altitude; the highest rate was observed in trees growing at high altitude (2.97 ± 0.9 mm/yr) compared to 2.23 ± 0.74 mm/yr at low altitude. In view of these results, this study indicates that a half-rotation of 7 years could allow an effective reconstitution of the bark of Prunus africana at the second passage on the remaining side of the same stem.

Assessing the effects of a drought experiment on the reproductive phenology and ecophysiology of a wet tropical rainforest community.

Climate change is expected to increase the intensity and occurrence of drought in tropical regions, potentially affecting the phenology and physiology of tree species. Phenological activity may respond to a drying and warming environment by advancing reproductive timing and/or diminishing the production of flowers and fruits. These changes have the potential to disrupt important ecological processes, with potentially wide-ranging effects on tropical forest function. Here, we analysed the monthly flowering and fruiting phenology of a tree community (337 individuals from 30 species) over 7years in a lowland tropical rainforest in northeastern Australia and its response to a throughfall exclusion drought experiment (TFE) that was carried out from 2016 to 2018 (3years), excluding approximately 30% of rainfall. We further examined the ecophysiological effects of the TFE on the elemental (C:N) and stable isotope (δ13C and δ15N) composition of leaves, and on the stable isotope composition (δ13C and δ18O) of stem wood of four tree species. At the community level, there was no detectable effect of the TFE on flowering activity overall, but there was a significant effect recorded on fruiting and varying responses from the selected species. The reproductive phenology and physiology of the four species examined in detail were largely resistant to impacts of the TFE treatment. One canopy species in the TFE significantly increased in fruiting and flowering activity, whereas one understory species decreased significantly in both. There was a significant interaction between the TFE treatment and season on leaf C:N for two species. Stable isotope responses were also variable among species, indicating species-specific responses to the TFE. Thus, we did not observe consistent patterns in physiological and phenological changes in the tree community within the 3years of TFE treatment examined in this study.

Two new magnoliid (Annonaceae, Lauraceae) tree species from Manabí, western Ecuador

Western Ecuador harbours high plant diversity and endemism. The region of Manabí has known intense deforestation over the last decades, but lowland rain forests persist in a network of small forest fragment patches. Here, we describe two new magnoliid tree species from a small privately owned forest fragment known as La Esperanza reserve, in the El Carmen canton (Manabí): Aniba ecuadorica (Lauraceae) and Guatteria esperanzae (Annonaceae). For both species a detailed morphological description, a preliminary conservation status following IUCN criteria, distribution maps and high quality photographs are provided. This represents the second species of Aniba known to occur in western Ecuador, while there are 14 species of Guatteria documented for Ecuador west of the Andes. Aniba ecuadorica is only known from two localities and has a preliminary IUCN conservation status of Critically Endangered, while Guatteria esperanzae is known from six localities and is suggested to be Endangered. Finally, we provide a quick overview of Guatteria species in western Ecuador with a key to the species in the region. The description of these two new tree species underlines the important need of prospection and conservation of the remnant forests in the Manabí region of western Ecuador. We also stress the importance of privately owned forest fragments for biodiversity conservation.

Two new species of Syzygium (Myrtaceae) from Sri Lanka, with lectotypification and recircumscription of Syzygium assimile

Two new species of Syzygium Gaertn. from Sri Lanka, S. aureum Jayasinghe and S. hemachandrae Jayasinghe, are described. Syzygium aureumis distinguished from S.grande (Wight) Walp. in having a thick ring of nectarial glands near the rim of the hypanthium and in having subglobose fruits tinged with red at ripening. Syzygium hemachandrae differs from S. assimile Thwaites in having a longer petiole, an elliptic to ovate-elliptic lamina with fewer lateral veins, a cylindrical to subcylindrical peduncle at its basal parts and approximately quadrangular secondary axes. Syzygium aureum, which was previously misidentified as Syzygium firmum Thwaites (=S. grande), is restricted to the southwestern lowland rainforests, while S. hemachandrae is confined to the moist monsoon forests of the intermediate zone of eastern Sri Lanka. Both new species were found to be included amongst the syntypes of Syzygium assimile. We therefore designate a lectotype and recircumscribe Syzygium assimile.

Tadpoles of Central Amazonia (Amphibia: Anura).

Amazonian lowland rainforests epitomize, as few other biomes, the terrestrial and freshwater biological diversity of our planet. We provide here a comprehensive description of the larval anurans of Central Amazonia, and their natural history. We base our analyses on fieldwork conducted in six terra-firme rainforest and two várzea floodplain sites during ~60 months between 1990 and 2013, complemented with an examination of museum specimens and a review of published literature. Ninety-nine species of anurans are known to occur in Central Amazonia. Of these, 84 species (85%) have a free-swimming exotrophic larva, six species (6%) have a terrestrial endotrophic larva, one species has a terrestrial exotrophic larva (1%) and another seven species (7%) have direct development of eggs into froglets. The life cycle of one species (1%) remains unknown. We formally describe and illustrate the larval stage of 68 species (i.e., 75% of the species with a known larval stage), five of them previously unkown and nineteen never described for Central Amazonia. We compile, review and update information on species natural history including reproductive modes, habitat use, phenology, and species interactions including diet, predators, competitors and parasites. Finally, we assessed the ecomorphological diversity in the region by the application of a system inspired in Altig & Johnston (1989), later updated by Altig & McDiarmid (1999), which recognizes tadpole guilds based on a combination of morphological and natural history data. Basic scientific information presented in this monograph provide the essential background for further studies on the ecological and evolutionary forces shaping anuran Amazonian assemblages, and their conservation.

Depth of Edge Influence in a Madagascar Lowland Rainforest and Its Effects on Lemurs’ Abundance

Edge effects result from interactions between adjacent habitats, which can modify abiotic and biotic conditions and produce various negative effects on biodiversity. Given the high degree of forest fragmentation in Madagascar, understanding lemur responses to edges is a conservation priority. We aim to determine the depth of edge influence in a continuous low-land rainforest of south-eastern Madagascar and identify the response of six lemur species. We surveyed lemur abundance along nine 1 km transects from May 2015 to July 2016 totaling 112.2 km of survey effort during the day and 88.5 km at night. We characterized the habitat structure via 33 plots centered along the line transects. We used Generalized Additive Models and Generalized Linear Models to test the effect of distance from the forest edge on vegetation parameters and animal encounter rates. Edge effect on the vegetation structure can be detected up to around 100 m in terms of tree diversity and density. We found a negative edge response for Madame Fleurette’s sportive lemurs (Lepilemur fleuretae) and collared brown lemurs (Eulemur collaris), and a positive edge response for Anosy mouse lemurs (Microcebus tanosi), Southern bamboo lemurs (Hapalemur meridionalis) and Southern woolly lemurs (Avahi meridionalis). Since around half of the forested areas in Madagascar are within 100 m of forest edge, taking into account edge effect is vital when producing estimates of population sizes and informing conservation management.