Soil moisture in forest island and adjacent ecosystems in Sub-Saharan Region

Forest islands are widely distributed throughout West Africa savanna landscape. Stated as direct outcome of anthropogenic activity, these mosaics are often found around villages and are known for their unique and luxuriant characteristics of tropical rainforest. Althought significant studies focus on their ecology, works on edaphic factors that govern their establishment are very scare. The objective of the current study was to evaluate soil moisture dynamics in forest islands compared to that of surrounding savannas and farmlands at five sites located along a precipation gradient in Burkina Faso. For two years, from 2016 to 2017, soil moisture was monitored at a depth of 0-80 cm using a neutron probe. The results highlighted a seasonal pattern ranging from 42±2% during the heavy rainy month (August) to 16±1% during the dry season (October-November). Significant differences in soil moisture content soil water profile and water stock at depth 0 to 80 cm were recorded between locations and land use patterns. In general, soil moisture was on average 58% less in forest island than in croplands across sites. Soil moisture content was lower in topsoil (0-20 cm) compared to deeper soil (40-80 cm). The Study demonstrated evident link of soil moisture dynamic with rainfall and the vegetation pattern.

Short Communication: New distributional record of Phyllanthus securinegoides Merr. (Phyllanthaceae) and Rinorea niccolifera Fernando (Violaceae) of Homonhon Island, Philippines

Romeroso RB, Tandang DN, Navarrete IA. 2021. Short Communication: New distributional record of Phyllanthus securinegoides Merr. (Phyllanthaceae) and Rinorea niccolifera Fernando (Violaceae) of Homonhon Island, Philippines. Biodiversitas 22: 501-506. Homonhon Island is an ultramafic forest island located on the east coast of Guiuan, Eastern Samar, Philippines. Due to the naturally rich deposit of Ni and Cr ore, the island is affected by mining activities where metallophytes thrive. These metallophytes have the potential to use in mining industries for ecological restoration. However, metallophytes are least documented in the Philippines. Phyllanthus securinegoides Merr. and Rinorea niccolifera Fernando is some of the metallophytes mostly documented in Surigao, Palawan, and Zambales, Philippines, but are not yet recorded in Samar. Moreover, these metallophytes are considered as new distribution records of metallophytes in the Philippines island. These plant resources must be conserved due to their physiological uniqueness. The study provides photographs and other relevant information of the collected species to compare the previous and present collections based on the previous and available literature.

Patterns of Diversity and Distribution of Arboreal Social Bees’ Beehives within Chimpanzees’ Home Range in a Forest-Savanna Mosaic (Comoé National Park, Côte d’Ivoire)

The goal of this study was to explain the patterns of diversity and distribution of arboreal social bees nesting in forest habitats of the Comoé National park, within the home-ranges of wild chimpanzees that consume their honey. Investigations were done using a total sixteen plots, one hectare each, established in three habitat types (mature forest island, secondary forest island and gallery forest). The diversity and distribution of arboreal social bees was estimated with visuals searches. The exploitation of the beehives of these bee by the chimpanzees was also evaluated using chimpanzees’ honey dipping tools as indicators. Results revealed five bees’ species belonging to two tribes; Meliponini (Meliponula ferruginea, Meliponula togoensis, Meliponula bocandei, Hypotrigona gribodoi) and Apini (Apis mellifera). Frequent exploitation of the honey of stingless bees by the chimpanzees was observed, except for H. gribodoi. Meliponula ferruginea was the most exploited species by chimpanzees. A total of 114 beehives were found in the overall established plots leading to an estimated density of 2.4 beehives/ha in the study area. Among the surveyed habitats, mature forest island was found to harbor the highest beehive density (4.2 beehives/ha), followed respectively by secondary-forest island (1.9 beehives/ha) and gallery forest (1.1 beehives/ha). Finally, all bee species were found nesting in cavities of trees with a DBH ranging from 15 to 87.3 cm, with a special preference for Dialium guinneense. However, the DBH of nesting trees and beehives’ height, measured from the ground level, did not significantly influence the honey exploitation by chimpanzees. In sum bee species diversity and distribution might be important in the survival of chimpanzees of a forest savanna landscape.

Assessing the population density of the spotted paca, Cuniculus paca, (Rodentia: Cuniculidae) on an Atlantic Forest island, southeastern Brazil

The spotted paca,Cuniculuspaca (Linnaeus, 1766), is a Neotropical, opportunistic, frugivorous caviomorph rodent, that inhabits primarily broadleaf forests. We aimed to provide the first estimates of density of C.paca for the Ilha Grande, an island located in the Atlantic Rain Forest biome of Brazil. Density and population size were estimated using the total number of individuals observed along each trail through the program DISTANCE 7. Our estimates of density and population size reinforces the importance of the Ilha Grande as an important reservoir of the species. Therefore, the results presented herein can be a starting point to support future action plans for the species, making predictions regarding the ecosystem and management and conservation of the spotted paca. Furthermore, the results can be used as a surrogate for other regions in which the species occurs.

Animal occurrence in fragmented forest habitats – important factors at the patch and landscape scale

To date, in research, the main determinants influencing animal assemblages in fragmented forests have been considered to be forest island area and degree of isolation. Such a simplistic approach may have detrimental effects on the obtained results and conclusions, since there are a large number of other factors determining animal persistence in forest islands. In order to identify these factors and evaluate their importance, we reviewed the scientific literature on the topic. In addition to the island area, also patch shape, edge effects and local plant community structure are crucial factors affecting animal assemblages at the forest island scale. At the landscape scale, the total number of forest islands and their combined area, matrix permeability, occurrence of wide ecological corridors as well as isolated trees and woodlands appear to be the most significant factors. Our review further indicates that many of these elements also tend to interact. For instance, edge effects may reduce the area of suitable habitat in a forest patch. Furthermore, some fragmentation effects may be masked by species traits e.g. mobility, food preferences or habitat specialisation. The landscape context also plays a crucial role in animal persistence in fragmented forests. We thus conclude that there is a strong need to investigate the above-mentioned components of habitat fragmentation at the local and landscape scale using appropriate bio-indicators.