Fire Occurrence Mediates Small-Mammal Seed Removal of Native Tree Species in a Neotropical Savanna

Seed dispersal and predation are critical processes for plant recruitment which can be affected by fire events. We investigated community composition of small mammals in gallery forests with distinct burning histories (burned or not burned ∼3 years before) in the Cerrado (neotropical savanna). We evaluated the role of these animals as seed removers of six native tree species, potentially mediated by the occurrence of fire. We sampled four previously burned sites and four unburned ones. Seed removal was assessed using two exclusion treatments: exclusive access of small rodents and access of all seed-removing vertebrates. The previous burning changed the structural characteristics of the forests, increasing the density of the understory vegetation and herbaceous cover, which determined differences in species composition, richness, and abundance of small rodents (abundance in the burned forests was 1/6 of the abundance in the unburnt ones). Seed removal rates across the six species were reduced in burnt forests in both treatments and were higher for the “all vertebrates” treatment. Other vertebrates, larger than small rodents, played a significant role as seed removers for five of the six species. The effects of fire were consistent across species, but for the two species with the largest seeds (Hymenaea courbaril and Mauritia flexuosa) removal rates for both treatments were extremely low in the burned forests (≦5%). The observed decline in small rodent seed predation in the burned forests may have medium to long-term consequences on plant communities in gallery forests, potentially affecting community composition and species coexistence in these forests. Moreover, fire caused a sharp decline in seed removal by large mammals, indicating that the maintenance of dispersal services provided by these mammals (mainly the agouti Dasyprota azarae) for the large-seeded species may be jeopardized by the burning of gallery forests. This burning would also affect several small mammal species that occur in the surrounding typical savanna habitats but also use these forests. Fire events have been increasing in frequency and intensity because of human activities and climate changing. This current scenario poses a serious threat considering that these forests are fire-sensitive ecosystems within the Cerrado.

Composition, richness and nestedness of gallery forest bird assemblages in an Amazonian savanna landscape: lessons for conservation

Gallery forests are important to the maintenance of a substantial portion of the biodiversity in neotropical savanna regions, but management guidelines specific to this forest type are limited. Here, we use birds as study group to assess if: (1) functional traits can predict the abundance and occupancy of forest species within a savanna landscape, (2) habitat structures influence the taxonomic, functional, and phylogenetic diversity of forest assemblages, and (3) less diverse gallery forest assemblages are a nested subset of more diverse assemblages living near continuous forests. Then, we propose strategies on how gallery forests can be managed to maintain their species assemblages amidst the fast expansion of human activities across tropical savanna landscapes. We studied 26 sites of gallery forests in an Amazonian savanna landscape and found that: (1) habitat specificity is the only functional trait that predicts species abundance and occupancy across a landscape; (2) phylogenetic diversity is negatively correlated with understory foliage density; (3) the percentage of forests and savannas around sites is positively correlated with both phylogenetic and functional diversity; (4) increasing human activities around gallery forest negatively influences taxonomic and functional diversity; and (5) forest bird assemblages are not distributed at random across the landscape but show a nested pattern caused by selective colonization mediated by habitat filtering. Our combined findings have three implications for the design of conservation strategies for gallery forest bird assemblages. First, maintaining the connectivity between gallery forests and adjacent continuous forests is essential because gallery forest bird assemblages are derived from continuous forest species assemblages. Second, because most species use the savanna matrix to move across the landscape, effectively managing the savanna matrices where gallery forests are embedded is as important to maintaining viable populations of forest bird species as managing the gallery forest themselves. Third, in savanna landscapes planned to be used for agriculture production, protecting gallery forests alone is not enough. Instead, gallery forests should be protected with surrounding savanna buffers to avoid the detrimental effects (edge effects and isolation) of human activities on their biodiversity.

The Big Naked-backed Bat, Pteronotus gymnonotus, Chiroptera, Mormoopidae, in its northernmost geographic distribution range

The Big Naked-backed Bat, Pteronotus gymnonotus, is one of the 15 species currently recognized of this genus, with relatively few specimens in scientific collections, besides being poorly studied. It has a geographical distribution spanning from México through Central America and reaching Perú and Brazil, in which it occupies a variety of habitats from desert to tropical forests below 400 meters above sea level. Here, we report the records that demonstrate its presence, and data about its natural history in southeastern México, the northernmost part of its geographic distribution range. Between June 2002 and July 2018, we captured specimens in 44 bat roosts located in southeastern México, including the Parque Estatal Agua Blanca, Macuspana, Tabasco; Grutas de Martínez de la Torre, Matías Romero Avendaño, Oaxaca; and in Cueva de Villa Luz, Tapijulapa, Tabasco. In the three locations mentioned, we recorded the occurrence of P. gymnonotus individuals, whose taxonomic identification at species level was corroborated by both morphological data and genetic analyses. Previously, the only records of P. gymnonotus in México were from only four specimens scattered across time, so these new recorded locations confirm the presence of this species in the country. In addition to this, in Agua Blanca State Park and Villa Luz Cave we found a reproductive resident population. The record from Grutas de Martínez de la Torre is located in the middle of the Tehuantepec Isthmus, a well known biogeographical barrier for many taxa in the transitional area to the Pacific lowland’s region. We suggest that the occurrence of P. gymnonotus in México is also associated with large remnants of evergreen and gallery forests, located in the lowland areas along the Gulf of México and in the north and east of the Tehuantepec Isthmus.

First record of Scinax centralis (Anura, Hylidae) in the Triângulo Mineiro region, state of Minas Gerais, southeastern Brazil, with further data on its vocalization

Scinax comprises more than 120 species which are split in two clades, the S. ruber and the S. catharinae clades. A few species within the S. catharinae clade occur in gallery forests of the Brazilian Cerrado. We here extend the distribution of S. centralis southwards based on new populations sampled in the banks of the Rio Paranaíba, in the borders of Minas Gerais (MG) and Goiás (GO) states, southeastern Brazil. We also provide further data on the species vocalization. Variation was seen among our population and topotypes regarding SVL and call dominant frequency, both likely representing a clinal variation. Our new population of S. centralis represents the first record of the species for the state of Minas Gerais.

Five new species of Streptocarpus (Gesneriaceae) from Katanga, D.R. Congo

Background and aims – Five new species of Streptocarpus (Gesneriaceae) are described from D.R. Congo in connection with preparing the family treatment for the Flore d’Afrique centrale.Methods – Standard herbarium practices were applied.Key results – Streptocarpus malachiticola sp. nov. is related to S. compressus and S. goetzei while S. bampsii sp. nov., S. malaissei sp. nov., S. salesianorum sp. nov., and S. schaijesii sp. nov. are related to S. michelmorei and S. solenanthus. The differences with these species are discussed and distribution maps for the new taxa are presented. An identification key for all known acaulescent species from D.R. Congo, Rwanda, and Burundi is provided. The conservation status of new species is preliminarily assessed. All taxa are range-restricted in Upper Katanga and the assessments are as follows: S. malachiticola: EN B1+2ab(iii), S. bampsii: CR B2ab(iii), S. malaissei: EN B1+2ab(iii), S. salesianorum: CR B2ab(iii), and S. schaijesii: EN B2ab(iii). Streptocarpus malachiticola is found on metalliferous rocks while the remaining species are either epiphytes in gallery forests (S. bampsii) or occur on humid rocks in gallery forests.

Soil fungal communities of ectomycorrhizal dominated woodlands across West Africa

Forests and woodlands in the West African Guineo-Sudanian transition zone contain many tree species that form symbiotic interactions with ectomycorrhizal (ECM) fungi. These fungi facilitate plant growth by increasing nutrient and water uptake and include many fruiting body-forming fungi, including some edible mushrooms. Despite their importance for ecosystem functioning and anthropogenic use, diversity and distribution of ECM fungi is severely under-documented in West Africa. We conducted a broad regional sampling across five West African countries using soil eDNA to characterize the ECM as well as the total soil fungal community in gallery forests and savanna woodlands dominated by ECM host tree species. We subsequently sequenced the entire ITS region and much of the LSU region to infer a phylogeny for all detected soil fungal species. Utilizing a long read sequencing approach allows for higher taxonomic resolution by using the full ITS region, while the highly conserved LSU gene allows for a more accurate higher-level assignment of species hypotheses, including species without ITS-based taxonomy assignments. We detect no overall difference in species richness between gallery forests and woodlands. However, additional gallery forest plots and more samples per plot would have been needed to firmly conclude this pattern. Based on both abundance and richness, species from the families Russulaceae and Inocybaceae dominate the ECM fungal soil communities across both vegetation types. The community structure of both total soil fungi and ECM fungi was significantly influenced by vegetation types and showed strong correlation within plots. However, we found no significant difference in fungal community structure between samples collected adjacent to different host tree species within each plot. We conclude that within plots, the fungal community is structured more by the overall ECM host plant community than by the species of the individual host tree that each sample was collected from.

Organic carbon in soils with different systems of use in Tacarimena Yopal, Colombia

Soil is an important carbon reservoir as it can store twice the amount that atmosphere does and three times the biomass, which makes it a key component for climate change (CC) mitigation projects. It is important to know the potential of soil organic carbon storage (SOC) in the main uses of the soli and their expected dynamics due to potential use changes. SOCS is estimated in 7 of the dominant land use systems in the area of the study, with 5 replicas as follows: 1) banana with shade (SAF+banana); 2) cocoa with shade (Ca+S); 3) citrus (C); 4) low silvopastoral system (SSPB); 5) high silvopastoral system (SSPA); 6) gallery forests (BG); and 7) bush forest (MM). SOC concentration was analyzed in samples composed of 25 soil sub-samples per plot, and the DA was estimated with the cylinder method in a simple per plot. All land uses studied can mitigate CC when storing SOC. BG was the system that showed the highest carbon storage. On the other hand, SAF+banana stored the least SOC (72,7 vs 33,4Mg/ha, respectively). Changes in land use can cause CO2 emissions or an addition in carbon fixation. Changes in land use that increase SOC allow CC mitigation, which makes them feasible for funding, thus allowing an improvement in the livelihood of local producers.

Cassia grandis (pink shower).

C. grandis is an element of lowland and riparian, semideciduous forests, occurring naturally from Mexico to South America. The species is usually 10-15 m high, and is very ornamental, especially due to its pink flowers which appear when the tree is partially defoliate and cover the entire crown. It is used in landscape design and urban arborization in tropical America, although in some cases its use is restricted due to the size of its fruits, which can reach 40-60 cm long. The species is recommended for live fences and revegetation in gallery forests in periodically flooded areas, but it is also adapted to a more or less pronounced dry season. C. grandis can be planted under direct sunlight in mixed tree systems, in fertile soils. The species has agroforestry potential for dry zones, especially in Central America, and is recommended for arborization of perennial crops and pastures, the fruits are highly appreciated by the cattle. C. grandis requires periodical pruning, however this may cause early decay and rot. The wood is used in construction, especially for carpentry, joinery, flooring, posts, beams, also for rustic furniture, tool handles, small bridges and boats. It is considered good for charcoal and fuelwood, and inadequate for cellulose and paper. In Central America, especially in Costa Rica, the membrane which surrounds the seeds is used as a substitute for chocolate, and is also used in many countries due to its medicinal properties. Researches have shown that extracts from this plant exhibit activity against the most common dermatophytes.