Local environmental context determines the colonisation of leaf shelters by arthropods: an experimental study

The magnitude of facilitation by shelter-building engineers on community structure is expected to be greater when they increase limited resources in the environment. We evaluated the influence of local environmental context on the colonisation of leaf shelters by arthropods in a Mexican evergreen tropical rainforest. We compared the species richness and abundance of arthropods (total and for different guilds) colonising artificially rolled leaves in habitats differing in understory heterogeneity (forest edge > old-growth forests > living fences). Arthropod abundance of the most representative arthropod taxa (i.e., Araneae, Blattodea, Collembola and Psocoptera) colonising the rolled leaves was greater at forest edge, a trend also observed for average arthropod abundance, and for detritivore and predator guilds. In addition, fewer arthropod species and individuals colonised the rolled leaves in the living fence habitat, a trend also observed for most arthropod guilds. As forest edge is expected to have a greater arthropod diversity and stronger density-dependent interactions, a greater limitation of refuges from competitors or predators may have determined the higher colonisation of the rolled leaves in this habitat. Our results demonstrate that local environment context is an important factor that affects the colonisation of arthropods in leaf shelters.

Three new Xylaria species (Xylariaceae, Xylariales) on fallen leaves from Hainan Tropical Rainforest National Park

Three new species of Xylaria on fallen leaves in Hainan Province of China are described and illustrated, based on morphological and molecular evidence. Xylaria hedyosmicola is found on fallen leaves of Hedyosmum orientale and featured by thread-like stromata with a long sterile filiform apex. Phylogenetically, X. hedyosmicola is closely related to an undescribed Xylaria sp. from Hawaii Island, USA and morphologically similar to X. vagans. Xylaria lindericola is found on fallen leaves of Lindera robusta and characterised by its subglobose stromata and a long filiform stipe. It is phylogenetically closely related to X. sicula f. major. Xylaria polysporicola is found on fallen leaves of Polyspora hainanensis, it is distinguished by upright or prostrate stromata and ascospores sometimes with a slimy sheath or non-cellular appendages. Xylaria polysporicola is phylogenetically closely related to X. amphithele and X. ficicola. An identification key to the ten species on fallen leaves in China is given.

Multi-Gene Phylogeny and Taxonomy of Hypoxylon (Hypoxylaceae, Ascomycota) from China

The Hypoxylon species play an important ecological role in tropical rainforest as wood-decomposers, and some might have benefical effects on their hosts as endophytes. The present work concerns a survey of the genus Hypoxylon from Hainan Tropical Rainforest National Park of China. Four new species: H. wuzhishanense, H. hainanense, H.chrysalidosporum, and H.cyclobalanopsidis, were discovered based on a combination of morphological characteristics and molecular data. Hypoxylon wuzhishanense is characterized by Rust pulvinate stromata, amyloid apical apparatus and brown ascospores, with most of the perispore being indehiscent in 10% KOH. Hypoxylon hainanense has effused–pulvinate and Violet stromata, amyloid apical apparatus, light-brown to brown ascospores with straight germ slit and dehiscent perispore. Hypoxylonchrysalidosporum is distinguished by glomerate to pulvinate stromata, highly reduced or absent inamyloid apical apparatus, and light-brown to brown ascospores with very conspicuous coil-like ornamentation. Hypoxyloncyclobalanopsidis has Livid Purple pulvinate stromata, highly reduced amyloid apical apparatus, faint bluing, brown ascospores and dehiscent perispore, and it grows on dead branches of Cyclobalanopsis. Detailed descriptions, illustrations, and contrasts with morphologically similar species are provided. Phylogenetic analyses inferred from ITS, RPB2, LSU, and β-tubulin sequences confirmed that the four new species are distinct within the genus Hypoxylon.

Forest Vegetation Cover in Yok Don National Park, Vietnam

Yok Don National Park is located in the tropical rainforest zone on the Central Highlands of Vietnam. The obtained results from the study undertaken on the composition of plant species and forest vegetation in National Park indicated a record of 856 species, 473 genera and 129 families that belongs to the four divisions of vascular plants. These includes: Lycopodiophyta, Polypodiophyta, Pinophyta and Magnoliophyta. Useful plants of 856 taxonomy species listed consists of 498 species of medicinal plants, 157 species of timber plants, 144 species of edible plants, 60 species of ornamental plants, 19 species of industrial plants, 10 species of fiber plants and 38 species of unknown use plants, respectively. During the duration of investigation, Peliosanthes teta Andrews was newly recorded in the forest vegetation of National Park. A variety of forest vegetations in the area under study is described. In this study, four major vegetation types of forest were identified in Yok Don National Park.

PEMETAAN BIOMASSA TEGAKAN HUTAN HUJAN TROPIS DI BUKIT MANDIANGIN MENGGUNAKAN CITRA SENTINEL-2 MSI

The preservation of standing biomass is one of the most vital elements for environmental sustainability and the sustainability of the forest itself. One of the actions that can be taken in an effort to maintain the sustainability of forest stand biomass is to map the distribution of biomass, and monitor changes or dynamics of stand biomass from time to time in a sustainable manner. This study aims to build a model based on remote sensing imagery to estimate the total biomass of tropical rainforest stands in Mandiangin Hill, South Kalimantan. The models developed in this study are based on vegetation indices extracted from Sentinel-2 MSI Imagery. A total of ten vegetation indices were tested in this study. For the construction process and validation of stand biomass estimation models, biomass information was measured directly in the field using a number of measuring plots. Stand biomass estimation models were made by correlating stand biomass information from the field with vegetation indices from Sentinel-2 MSI Imagery. The results showed that the most accurate model for estimating the biomass of tropical rainforest stands was 9.5806.exp (0.1454.PSSRa). Where PSSRa is Pigment Specific Simple Ratio. This model has a correlation coefficient (R2) of 0.876, a Mean Absolute Percentage Error (MAPE) of 16.8%, and a Root Mean Square Error (RMSE) of 32.6. The estimation results show that the total biomass of the Bukit Mandiangin tropical rainforest stands is between 11.7 to 998.5 Mg/ha, with an average biomass of 135.8 Mg/ha. Furthermore, the estimation of stand biomass in this study is limited to woody vegetation with a DBH of 10 cm and above. The PSSRa model with various improvements can be used to accurately estimate stand biomass

Enzymatic Bioprospecting of Fungi Isolated from a Tropical Rainforest in Mexico

The humid tropical environment provides an ideal place for developing a high diversity of plants; this is why it is an interesting site for the enzymatic bioprospecting of fungi that are responsible for the recycling of organic matter in an efficient and accelerated way and whose enzymes could have multiple biotechnological applications. For this study, 1250 isolates of macroscopic and microscopic fungal morphotypes were collected from soil, leaf litter, and wood. One hundred and fifty strains (50 from each source) were selected for the enzymatic screening. From the first phase, 51 strains with positive activity for laccase, protease, amylase, xylanase, and lipase enzymes were evaluated, of which 20 were isolated from leaf litter, 18 from the soil, and 13 from wood. The 10 best strains were selected for the enzymatic quantification, considering the potency index and the production of at least two enzymes. High laccase activity was detected for Trametes villosa FE35 and Marasmius sp. CE25 (1179 and 710.66 U/mg, respectively), while Daedalea flavida PE47 showed laccase (521.85 U/mg) and protease activities (80.66 U/mg). Fusarium spp. PH79 and FS400 strains had amylase (14.0 U/mg, 49.23 U/mg) and xylanase activities (40.05 U/mg, 36.03 U/mg) respectively. These results confirm the enzymatic potential of fungi that inhabit little-explored tropical rainforests with applications in industry.

A new species of planthopper from Costa Rica in the genus Oropuna from palms in lowland tropical rainforest

The derbid genus Oropuna is a small taxon of Neotropical planthoppers in the tribe Cenchreini comprised of three species. Recent survey work on palms for planthoppers in Costa Rica resulted in the discovery of a fourth species, Oropuna halo sp. n. In this study the new species is described and a key to the four species is provided along with sequence data for the cyctochrome c oxidase subunit I (COI) and 18S rRNA gene for the novel taxon.