Lowland Evergreen Forest Research Articles

Why did the Hornbill not cross the river? Upland habitats rather than a physical barrier limit the distribution of the Brown Hornbill

AbstractAimIn continuous environments, niche limits of species often determine their distribution limits. However, when these limits spatially coincide with a perceived dispersal barrier, the determinants of species' ranges may be confounded. We investigate the distribution pattern of the Brown Hornbill (Aves: Bucerotidae), which spans significant riverine barriers, but stops south of the Brahmaputra River. Considering its preference for low‐elevation evergreen forests, we posit that the lack of sufficient habitats north of the Brahmaputra prevents dispersal of the Brown Hornbill, and not the river itself.LocationThe Brahmaputra valley and the Indo‐Burma hotspot.TaxaAnorrhinus austeni, Aceros nipalensis.MethodsWe analysed citizen‐science occurrence data on hornbill presence against a suite of climatic, canopy‐specific and topographical predictors to model the environmental niche of the Brown Hornbill. We used presence‐only maximum entropy modelling in an information theoretic framework, in conjunction with constructing binary logistic regression models using presence and pseudoabsence data. We compared niche models of the Brown Hornbill and the Rufous‐necked hornbill, a close relative with a similar distribution, but which has spanned the Brahmaputra River.ResultsDespite the presence of suitable wet‐evergreen forests north of the Brahmaputra River, the hilly terrains in the region act as a biogeographic barrier for the Brown Hornbill, which prefers lowland evergreen forests. Further, highly suitable regions for the Brown and the Rufous‐necked Hornbills precisely delineate low and high‐elevation evergreen forests respectively, indicating that these birds are separated along an elevational axis.Main ConclusionsThe Brahmaputra River lies at the cusp of two subtly different environmental regimes. It may therefore serve as the niche limit for certain organisms and not as a physical obstacle to their dispersal. Our study implicitly predicts how widespread deforestation prevalent in the lowland evergreen forests of this region adversely impacts the distributions of organisms that depend on them, such as the Brown Hornbill. Further, our study proffers an approach to ascertain determinants of species distributions in a hypothesis testing framework.

Floristic Composition and Diversity of a Transect in a Locality of the Lowland Evergreen Forest of the Amazon of Cuyabeno City

The present research determined the high diversity and structure of the lowland evergreen forest of the Amazon in a locality (Rey de los Andes) of Cuyabeno city, since there is no updated information on this important biome. The linear transect methodology of 0.1 hectares was applied along the river and separated 2 m from the edge, all trees and shrubs with a diameter at breast height greater than 10 cm were measured, fertile botanical samples were collected and were processed and identified in the CHEP Herbarium. A total of 86 individuals were obtained between trees and shrubs distributed in 20 families, 39 genera, and 41 species, and a basal area of 10.95 m2 was obtained. The dominant family was Fabaceae with seven genera and the most frequent species were Astrocaryum urostachys, Celtis sp., and Leonia crassa. The highest importance value index was 15.56% for Astrocaryum urostachys and 10.33% for Otoba glycycarpa and the Simpson Diversity Index was 0.96. The diameters obtained were classified into 3 diameter classes, where Class I was made up of 68 individuals, which represents 79.07% of the total. It is concluded that the forest of the Rey de los Andes community has a high diversity of tree and shrub species. Likewise, considering the type of vegetation found, list of species, site, and diameters obtained, it can be stated that it is a well-preserved forest.
 Keywords: Floristic composition, Lowland evergreen forest, Cuyabeno.
 Resumen 
 La presente investigación determinó la alta diversidad y estructura del bosque siempreverde de tierras bajas de la amazonía de una localidad (Rey de los Andes) del Cantón Cuyabeno; ya que no se cuenta con información actualizada de este importante bioma. Se aplicó la metodología de transecto lineal de 0,1 hectáreas a lo largo del río y separado a dos metros del borde, se midió todos los árboles y arbustos con diámetro a la altura del pecho mayor a 10 centímetros, se recolectó muestras botánicas fértiles y fueron procesadas e identificadas en el Herbario CHEP. Se obtuvo un total de 86 individuos entre árboles y arbustos distribuidos en 20 familias, 39 géneros y 41 especies y se obtuvo un área basal de 10,95 m2; la familia dominante fue Fabaceae con siete géneros y las especies más frecuentes fueron Astrocaryum urostachys, Celtis sp. y Leonia crassa. El Índice de Valor de Importancia más alto fue de 15,56% para Astrocaryum urostachys y de 10,33% para Otoba glycycarpa y el Índice de Diversidad de Simpson fue de 0,96. Los diámetros obtenidos fueron clasificados en 3 clases diamétricas, donde la Clase I estuvo conformada por 68 individuos lo que representa al 79,07% del total. Se concluye que el bosque de la comunidad Rey de los Andes posee una alta diversidad de especies de árboles y arbustos; así mismo tomando en cuenta el tipo de vegetación encontrada, listado de especies, sitio y diámetros obtenidos, se puede manifestar que se trata de un bosque bien conservado.
 Palabras Clave: Composición florística, Bosque siempreverde, Cuyabeno

Species Composition and Structure of Habitats Exploited by Elephants (Loxodonta Africana Cyclotis) in the Campo Maan Forest, South Region, Cameroon

Purpose: The main objective of this study was to determine the species composition and structure of habitats exploited by elephants in the Campo Maan Forest.
 Methodology: Using the transect methods, purposively, 1km transects were laid along identified feeding tracts in various habitats. 15 transects with each having 4 quadrates of 30x30m were established at interval of 220m summing up to a total of 5.4 hectares of land covered for the study within which data was collected. In the quadrates, all vascular plants with dbh >10cm (diameter at breast height about 1.3m above the ground) were measured and identified. In each quadrate, four subplots of 15mx15m were placed at the corners to sample understory and herbs.
 Findings: Results reveal a total of 1113 individual trees with DBH of ≥ 10 cm identified and measured belong to 49 species from 24 families. Fabaceae was the most dominant family of plants with 425 individual trees counted with Caesalpinioideae being the dominant specie type (116); followed by Calpocalyx heitzii (92). Lowland evergreen forest (Casalpinioideae) recorded the highest number of tree species counted (462, 41.5%) of the total tree species. Trees DBH varies between 10 and 64 cm with mean values of 29.45±11.48 cm, 23.3±7.759 cm, 27.69±9.189 cm and 25.75±14.056 cm for Lowland evergreen forest (Casalpinioideae), Lowland evergreen forest (mixed), Coastal forest (Sacoglotis gabonensis) and Coastal forest (mixed) respectively. A large number of trees recorded heights of above 30m though it was higher for Lowland evergreen forest (mixed), Coastal forest (Sacoglotis gabonensis) and the Coastal forest (mixed). For the understory, the dominant specie types are Scaphopetalum blackii, Palisota ambigua, Asystasia macrophylla, Podococcus barteri, Microdesmis puberula, Heistera pavifora, Haumania danckelmaniana, Alchornea floribunda all counting 9 and 10 individual Trees). Results revealed highly positive and significant correlations between trees DBH and height (r=0.84, p=0.000). The Shannon’s diversity index indicates that the tree diversity for all habitats are fairly even with Coastal forest (Sacoglotis gabonensis) having a value of 4.73. The Coastal forest (mixed) shows the highest rate of basal area (76.39); followed by Coastal forest (Sacoglotis gabonensis) (41.50) and Lowland evergreen forest (Casalpinioideae) (32.26), all indicating high basal areas.
 Recommendation: Further studies on habitat fragmentation are needed to assess its effects on elephant movement within the area.

Biomass and Carbon Stock Assessment of Trees in the Lowland Evergreen Forest of Mt. Iraya, Batanes, Philippines

Biomass and Carbon Stock Assessment of Trees in the Lowland Evergreen Forest of Mt. Iraya, Batanes, Philippines

Mexico’s Forest Diversity: Common Tree Species and Proposed Forest-Vegetation Provinces

We report a relatively rare study of a national forest inventory in a megadiverse country with the systematic collection of herbarium specimens. The taxonomic identification of 22,659 herbarium collections from 6942 sites of Mexico’s national forest inventory resulted in 1464 native tree species (approximately half of Mexico’s estimated total), in 470 genera and 117 plant families. We compared visual tree-species identifications in the field by hired crews, with much more rigorous identification of submitted (mostly sterile) herbarium specimens by experienced taxonomists and specialists at the National Herbarium: for 40% of the 22,659 collections, the identification of species names from the field was confirmed, for 32% it was corrected at the herbarium, and 27% had been sent without any identification. The most commonly collected plant families were Fagaceae (oak family, 21.7% of all collections), Fabaceae (legumes, 17.7%), and Pinaceae (pine family, 13.3%). The most commonly collected tree species in six major forest-vegetation types were Pinus leiophylla in “coniferous forest”, Quercus magnoliifolia in “highland broadleaf forest”, Liquidambar styraciflua in “mountainous cloud forest”, Bursera simaruba in “lowland evergreen forest”, Lysiloma divaricatum in “lowland dry forest”, and Parkinsonia microphylla in “xerophilous scrub”. We overlapped the six major forest-vegetation types with Mexico’s 15 mainland floristic provinces, as circumscribed by Rzedowski. This resulted in 75 so-called forest-vegetation provinces, of which 35 had at least 20 collection sites. The similarity of species composition among these 35 forest-vegetation provinces was only 17–34% with the Jaccard community index, and 15–42% with the Morisita-Horn community index. The number of physically undetected species was estimated statistically for the 35 forest-vegetation provinces, which indicates that there are forest-vegetation provinces, where the number of species could be up to 8.8-fold higher than those detected in the present work. Finally, we suggest a method to distribute sites optimally among the country in future forest inventories, such as to minimize the average area represented by the sites in each forest-vegetation province.

A proto-monsoonal climate in the late Eocene of Southeast Asia: Evidence from a sedimentary record in central Myanmar

The Burma Terrane has yielded some of the earliest pieces of evidence for monsoonal rainfall in the Bay of Bengal. However, Burmese ecosystems and their potential monsoonal imprint remain poorly studied. This study focuses on the late Eocene Yaw Formation (23° N) in central Myanmar, which was located near the equator (c. 5° N) during the Eocene. We quantitatively assessed the past vegetation, climate, and depositional environments with sporomorph diagrams, bioclimatic analysis, and sequence biostratigraphy. We calculated the palynological diversity and drew inferences with rarefaction analysis by comparing with four other middle to late Eocene tropical palynofloras. Palynological results highlight a high floristic diversity for the palynoflora throughout the section formed by six pollen zones characterized by different vegetation. They indicate that lowland evergreen forests and swamps dominated in the Eocene Burmese deltaic plains while terra firma areas were occupied by seasonal evergreen, seasonally dry, and deciduous forests. This vegetation pattern is typical to what is found around the Bay of Bengal today and supports a monsoon-like climate at the time of the Yaw Formation. Bioclimatic analysis further suggests that in the late Eocene, the Yaw Formation was more seasonal, drier, and cooler compared to modern-day climate at similar near-equatorial latitude. More seasonal and drier conditions can be explained by a well-marked seasonal migration of the Intertropical Convergence Zone (ITCZ), driver of proto-monsoonal rainfall. Cooler temperatures in the late Eocene of central Myanmar may be due to the lack of adequate modern analogues for the Eocene monsoonal climate, while those found at other three Eocene Asian paleobotanical sites (India and South China) may be caused by the effect of canopy evapotranspirational cooling. Our data suggest that paleoenvironmental change including two transgressive–regressive depositional sequences is controlled by global sea level change, which may be driven by climate change and tectonics. The high diversity of the Yaw Formation palynoflora, despite well-marked seasonality, is explained by its crossroads location for plant dispersals between India and Asia.

Lukea gen. nov. (Monodoreae-Annonaceae) with two new threatened species of shrub from the forests of the Udzungwas, Tanzania and Kaya Ribe, Kenya

SummaryA new genus, Lukea Cheek & Gosline (Annonaceae), is erected for two new species to science, Lukea quentinii Cheek & Gosline from Kaya Ribe, SE Kenya, and Lukea triciae Cheek & Gosline from the Udzungwa Mts, Tanzania. Lukea is characterised by a flattened circular bowl-shaped receptacle-calyx with a corolla of three free petals that give the buds and flowers a unique appearance in African Annonaceae. Both species are extremely rare shrubs of small surviving areas of lowland evergreen forest under threat of habitat degradation and destruction and are provisionally assessed as Critically Endangered and Endangered respectively using the IUCN 2012 standard. Both species are illustrated and mapped. Material of the two species had formerly been considered to be possibly Uvariopsis Engl. & Diels, and the genus Lukea is placed in the Uvariopsis clade of the Monodoreae (consisting of the African genera Uvariodendron (Engl. & Diels) R.E.Fries, Uvariopsis, Mischogyne Exell, Dennettia Baker f., and Monocyclanthus Keay). The clade is characterised by often conspicuous, finely reticulate quaternary nervation, incomplete or absent connective shields (in Annonaceae the connective shield is usually complete) and free petals (except in some Uvariopsis). Morphologically Lukea is distinct for its broad, turbinate, fleshy pedicel, a potential synapomorphy within Monodoreae. It appears closest morphologically to the West African monotypic Monocyclanthus, since it shares a trait unusual in the Annonaceae: the calyx in both genera forms a shallow bowl (calyx lobes are absent or vestigial), barely enclosing the base of the petals at anthesis, which persists, living and green, in the mature fruit. However, on recent molecular phylogenetic evidence, Lukea is sister to Mischogyne and the two split c. 20 million years BP, while Monocyclanthus is sister to Dennettia. The placement of Lukea within the Uvariopsis clade is discussed.

HULLETTIA King ex Hook. f. (Moraceae), A newly recorded genus to the Flora of Vietnam, with its lectotypification and a revised key to Vietnamese Moraceae

Hullettia King ex Hook. f. (Moraceae) is newly recorded to the flora of Vietnam. A specimen discovered in the lowland secondary evergreen forest of Song Hinh protection forest, Phu Yen province, central Vietnam was identified as Hullettia dumosa King ex Hook. f. It was earlier known from peninsular Myanmar, peninsular Thailand, peninsular Malaysia, Singapore, and Sumatra. Type material of this species is analyzed, and lectotype is designated (Scortechini s.n., K: K000898664). Photographic illustrations of studied specimens are provided. A key to the Vietnamese genera of Moraceae is presented.

Evergreen forest types of the central plains in Cambodia: floristic composition and ecological characteristics

Current vegetation maps show evergreen forests of Cambodia as one homogenous forest type. However, ecological field studies in the central plains demonstrated a heterogenous mosaic of different evergreen forest types, each with a unique species composition and ecological characteristics. Based on six botanical expeditions, we describe four lowland evergreen forest types: 1) riverine forest dominated by Dipterocarpus costatus (Dipterocarpaceae); 2) tall dipterocarp forest dominated by Anisoptera costata (Dipterocarpaceae); 3) swamp forest dominated by Macaranga triloba (Euphorbiaceae); and 4) ‘Sralao', an open forest with a monodominance of Lagerstroemia cochinchinensis (Lythraceae). Ordination by non‐metric multi‐dimensional scaling (NMDS) indicated that the four forest types represent well‐separated floristic entities with Sralao as the most deviant community. The highest species diversity was found in the riverine forest ( = 2.65), followed by tall dipterocarp forest ( = 2.53) and swamp forest ( = 2.34), whereas the Sralao forest had the lowest species diversity ( = 1.64). We argue that botanical fieldwork remains essential to refine vegetation maps otherwise based on remote sensing, and that knowledge of species composition is essential to conserve Indochina's vanishing evergreen forest biodiversity.

Two new species of Kalcerrytus Galiano, 2000 (Araneae: Salticidae) from Tambopata River, Madre de Dios, Peru

Jumping spiders of the genus Kalcerrytus inhabit the moist tropical forests of the Neotropical region. This genus includes 18 species, only both sexes are known for half of these and of K. leucodon only the female is known; the vast majority of species are registered for Brazil and there are records from Bolivia, Ecuador and French Guiana. Males are characterized by having a robust palp and more sclerotized than in other genera of the Freyina subtribe; females are distinguished by their broad epigynum with large funnel-shaped copulation openings and oblique edges. Two new species are herein described, and they represent the first record of the genus in Peru. Kalcerrytus mapinguari sp. nov. and Kalcerrytus yacuruna sp. nov. were collected in the Tambopata River region, which is characterized by its highly biodiverse tropical lowland evergreen forests. Illustrations of both male and female genitalia are provided as well as maps recording their distribution.

Richness and Distribution of Orchids (Orchidaceae) in the Forests of Mount Busa, Sarangani, Southern Mindanao, Philippines

Orchids are one of the most diverse yet threatened plant families in the world and the Philippines. Despite the new species discoveries of orchids in the country in recent years, diversity and distribution studies are still severely lacking. Here, we provide a list of orchid species found among different forest types in Mount Busa and provide information on the species’ altitudinal and vertical distributions and ornamental use. We recorded 108 species of orchids from 51 genera, of which 53 species are endemic to the Philippines and 15 species are known only to occur on Mindanao island. Species composition differed among forest types, with the MASLEF (mixed advanced secondary lowland evergreen forest) hosting the highest number of orchid species recorded, followed by the UMF (upper montane forest), LMF (lower montane forest), and MESLEF (mixed early secondary lowland evergreen forest). Our results suggest a relatively rich and distinct orchid diversity among different forest types in Mount Busa that reinforces the high conservation value of the mountain range.

Effect of environmental gradients on tree distribution in lowland dry evergreen forest, northeastern Thailand

Effect of environmental gradients on tree distribution in lowland dry evergreen forest, northeastern Thailand

Understorey to canopy vertebrate fauna of a lowland evergreen forest in Mt. Makiling Forest Reserve, Philippines.

We examined the vertical stratification of forest wildlife, from the ground up to the canopy layer, within a 2-hectare permanent plot of lowland evergreen rainforest on the Mt. Makiling Forest Reserve. Our aim was to determine the species richness of the different forest layers and evaluate their ecosystem services. Understorey, sub-canopy and canopy sampling were conducted during July 2016, March to April 2017 and February to March 2018, respectively. We were able to record a total of 68 species, consisting of 11 amphibians, 15 reptiles, 25 birds and 17 mammals. Increasing species richness with increasing vertical stratification was observed for both reptiles and mammals. For birds, the peak richness was observed in the sub-canopy and then decreased in the canopy. A decreasing trend was observed with amphibians wherein the peak species richness was observed in the understorey. Increasing vertical stratification influenced vertical habitat use and species richness. For the similarity index, the same pattern was observed for all species groups. Highest similarity was observed between the sub-canopy and the canopy and the least similarity was observed between the understorey and canopy. These results indicate that the understorey and the canopy host different species groups, thus, sampling of the understorey alone, often done in biodiversity surveys, may lead to the underestimation of species richness in an area.

Novelties from the Northern Mountains Complex of Madagascar V: A new threatened Pandanus (Pandanaceae) from the Kalobinono massif

Callmander, M.W., R. Razakamalala, I. Luino, R.L. Andriamarisoa & S. BUERKI (2020). Novelties from the Northern Mountains Complex of Madagascar V: A new threatened Pandanus (Pandanaceae) from the Kalobinono massif. Candollea 75: 99–105. In English, English and French abstracts.A new species of Pandanus Parkinson (Pandanaceae) endemic to Madagascar is described as Pandanus kalobinonensis Callm., Razakamal. & Luino and illustrations are provided. The new species is restricted to the north-western lowland moist evergreen forests of the Kalobinono massif. Pandanus kalobinonensis can easily be morphologically distinguished from other members of the genus by its small solitary globose syncarp borne on a short peduncle, monocarpellate drupes, and single spiniform stigma with an adaxial stigmatic groove. Despite the occurrence of both collections within limits of the newly designated Galoko-Kalobonino Protected Area, the new species is preliminary assessed as “Endangered” [EN] using the IUCN Red List Criteria.

<p><strong>Emended description and new localities of <em>Oxygyne shinzatoi </em>(Burmanniaceae/Thismiaceae), with discussion of phylogenetic relationships of <em>Oxygyne </em>from Japan and Africa</strong></p>

During a recent survey, Oxygyne specimens were discovered in three lowland evergreen forests on Okinawa Island, Japan. After morphological investigation, we identified the specimens as O. shinzatoi. Intriguingly, the colour of the specimens from one of the localities was significantly different from that of specimens collected from both the type and two of the new localities. Furthermore, morphological analysis also revealed clear differences between specimens collected from the type locality, including the type specimen, and previous descriptions of O. shinzatoi. Therefore, an amended description of O. shinzatoi is provided, based on the type and newly collected specimens. Phylogenetic relationships of Oxygyne from Japan and western Central Africa are also discussed, with consideration of the characteristics of newly discovered colour variation.

Cololejeunea metzgeriopsis, a new species record for Thailand

Cololejeunea metzgeriopsis (K. I. Goebel) Gradst. et al., a neotenic liverwort, was newly discovered in lowland evergreen forest, southern Thailand. A description and illustrations of Thai plants are provided.

Thysananthus ciliaris (Lejeuneaceae, Marchantiophyta): a new record of Thysananthus species for Thailand

Thysananthus ciliaris (Sande Lac.) Sukkharak, a rare species from Sumatra and Peninsular Malaysia, was newly discovered in lowland evergreen forest, southern Thailand. A detailed description and illustrations are here provided.

Plant diversity and structure of forest habitat types on Dinagat Island, Philippines

Logging, mining and land conversion together threaten Dinagat Island. Diversity and structure of forest habitat types were determined as basis for conservation and management. Identification of forest habitat types was based on habitat's physical characteristics.Six forest habitat types were identified covered by 432 native plant species classified into 87 families and 203 genera, 40 plant species were endemic to Dinagat Island. Of the 432 species, 58% recorded in lowland evergreen forest (LEF), 16% in upper montane, 15% in forest over limestone, 6% in lower montane forest (LMF), 4% in mangrove forest, and 1% in beach forest, with average species diversity of 3.32.Trees in LEF were bigger, taller and larger in basal area as compared with other habitat types. Dominant species was Xanthostemon verdugonianus Náves ex Fern.-Vill with importance value of 9.857%.Native plant species was an asset for the mineral resource industry for site rehabilitation and conservation.

Gastrodia albidoides (Orchidaceae), a new species record for Thailand

Gastrodia albidoides, a rare orchid species previously known only from Yunnan, China, was newly discovered in lowland evergreen forest in peninsular Thailand. A description and photographs are provided.

Mapping Distinct Forest Types Improves Overall Forest Identification Based on Multi-Spectral Landsat Imagery for Myanmar’s Tanintharyi Region

We investigated the use of multi-spectral Landsat OLI imagery for delineating mangrove, lowland evergreen, upland evergreen and mixed deciduous forest types in Myanmar’s Tanintharyi Region and estimated the extent of degraded forest for each unique forest type. We mapped a total of 16 natural and human land use classes using both a Random Forest algorithm and a multivariate Gaussian model while considering scenarios with all natural forest classes grouped into a single intact or degraded category. Overall, classification accuracy increased for the multivariate Gaussian model with the partitioning of intact and degraded forest into separate forest cover classes but slightly decreased based on the Random Forest classifier. Natural forest cover was estimated to be 80.7% of total area in Tanintharyi. The most prevalent forest types are upland evergreen forest (42.3% of area) and lowland evergreen forest (21.6%). However, while just 27.1% of upland evergreen forest was classified as degraded (on the basis of canopy cover <80%), 66.0% of mangrove forest and 47.5% of the region’s biologically-rich lowland evergreen forest were classified as degraded. This information on the current status of Tanintharyi’s unique forest ecosystems and patterns of human land use is critical to effective conservation strategies and land-use planning.