Dense Evergreen Forests Research Articles

EVALUATION DE LA PRODUCTION FRUITIERE EN PEUPLEMENTS NATURELS DUNJANSANG (RICINODENDRONHEUDELOTII BAIL.) EN ZONE FORESTIERE A PLUVIOMETRIE BIMODALE DANS LA REGION DU CENTRE (CAMEROUN)

RicinodendronheudelotiiBail., commonlyknown as Njansang, is a speciesendemic to the dense evergreenforests of Africa. Its fruits are highlyprized and are usedboth for home consumption and for marketing in Cameroon and in the Congo Basin in general.This studyaims to evaluate fruit production of thisspeciesunder the influence of two types of land use. To do this, itwasconducted in the bimodal rainfallforest zone located in the Central region (Cameroon) between the months of August and October of the years 2017 to 2019.Thus, individuals of R. heudelotiiwereidentified and their fruit production wasevaluated in agroforestry plots based on cocoatrees and in more or lessdegradedforests.The resultsobtainedshowedthat the fruit production per plant of Njansangis 8.34 ± 7.45 kg per year.It did not varysignificantlyfromyear to year, but wassignificantlyhigher in September.Moreover, itwassignificantlyhigher in cocoa agro-foreststhan in weaklydisturbedforests.Theseresultscould help forecastharvests and production sales for the month or year.Also, theycouldstimulate the introduction and integration of R. heudelotiiindividualsintococoa agro-forestrysystems and thusboost domestication, development of the species and the diversification of agroforestry production systems.

<p><strong><em>Knema flavostamina </em></strong><strong>(Myristicaceae), a new species from southern Western Ghats, India</strong></p>

Myristicaceae Brown (1810: 399), the pantropical ‘nutmeg family’, comprise 21 genera and 520 species (Christenhusz & Byng 2016). The family thrives in the dense evergreen forests of the Western Ghats and is represented by three genera, viz. Gymnacranthera (Candolle 1855: 31) Warburg (1896: 94), Knema Loureiro (1790: 604) and Myristica Gronovius (1755: 141) (Nayar et al. 2014). Knema, one of the major genera of Myristicaceae with 93 species, is distributed in Indomalaya (Mabberley 2018). In India, the genus is represented by eight species, of which the endemic Knema attenuata (Wallich in Hooker & Thomson, 1855: 157) Warburg (1896: 590) is the only species in the Western Ghats (Sinclair 1961, Nayar et al. 2014, Banik & Bora 2016).

RETRACTED ARTICLE: Study on peak cluster-depression rocky desertification landscape evolution and human activity-influence in South of China

ABSTRACT The peak cluster depression is a concentrated distribution of karst rocky desertification hazards in southern China. Under special water and soil conditions, the bare peak cluster slopes are covered with dense evergreen forests. The traditional human farming activities have affected the forest landscape on the slopes of the peak clusters, causing the phenomenon of point-like rock exposure on the slopes of the peak clusters, which can be repaired by natural forces; modern destructive economic activities rapidly degenerate the karst forest landscape into planar rocks. The exposed landscape is superimposed on the fragile karst environment, forming a large area of rocky desertification landscape, dissipating the basic conditions for the production and living of rural communities, and forming “karst ecological poverty”. “Blocking the mountains and nourishing forests” is the best way to restore the landscape of the peak forests. “Artificial afforestation” can provide seed banks for the areas with strong rocky desertification. Appropriate development of economic forests is an important measure to increase the income of farmers.

Isotopic reconstruction of Proboscidean habitats and diets on Java since the Early Pleistocene: Implications for adaptation and extinction

Since its sub-aerial emergence, Java has experienced multiple tectonic, geographic and climatic changes, which affected the megafaunal occupation, adaptation and succession. Six Proboscidean taxa have been found from various localities throughout Java extending back to the Early to Late Pleistocene. The six taxa are: Stegoloxodon indonesicus, Sinomastodon bumiajuensis, pygmy Stegodon sp., Stegodon trigonocephalus, Elephas hysudrindicus and Elephas maximus, in which respective taxa are included in successive faunal stages. The aim of this research was to reconstruct the succession of Proboscidea in Java and the adaptation of each taxon to environmental changes by incorporating stable isotope analysis with the fossil faunal record, geology and stratigraphy. We conducted stable carbon (δ13C) and oxygen (δ18O) isotope analysis of the carbonate phase in the tooth enamel of six proboscidean taxa from numerous localities and ages. Our results suggest that for the earliest terrestrial fauna from Java, represented by Stegoloxodon indonesicus, the feeding ecology was restricted to a closed canopy rainforest during the earliest Pleistocene, while towards the late Early Pleistocene, the successive taxon, Sinomastodon bumiajuensis, was adapted to different or increasingly drier grassy habitats. C4 expansion on the island took place since the later part of the Early Pleistocene (before 1.5 Ma) and continued until the Middle Pleistocene, as suggested by the carbon and oxygen isotope composition of assemblages of proboscidean taxa from Sangiran, Kedung Brubus, Trinil, and western Java, which also predominantly display the expected range of C4-dominant feeders. However, the occurrence of mixed C3/C4 feeder Proboscidea in the Ngandong Fauna suggests that fragmented dense evergreen forests, shrubby or woodland vegetation reappeared towards the end of the Middle Pleistocene. This environmental shift is detected in the later stage of the Middle Pleistocene, as the dietary preference of all analysed samples from individuals from this age shifted back from a C4-dominated into a C3-dominated diet, which suggests a change from a dry to more humid climate conditions.

Monitoring tropical forest ungulates using camera‐trap data

AbstractTropical forest ungulates are poorly known and, despite their ecological and conservation significance, there are few studies on their density and abundance. I estimated densities of lesser oriental chevrotain Tragulus kanchil in the Southern Cardamom National Park, south‐west Cambodia using camera‐trap encounter rates and fitting a random encounter model (REM) that does not require individual identification of animals. This represents the first use of REM on forest ungulates in mainland tropical Asia and provides the first density estimate for any chevrotain species in mainland South East Asia. Sixty‐five camera‐trap stations generated 501 encounters of lesser oriental chevrotain across >8200 camera‐trap nights within a systematic random camera‐trap grid of 200 km2 in the Southern Cardamom National Park. Density of lesser oriental chevrotain was estimated at between 57 and 98 ( 81) individuals per km2. The random deployment of camera‐traps, a prerequisite of the REM, did not prevent the detection of the majority of ground‐dwelling large mammal species likely to be present in the study site. Despite its slow uptake by field conservationists, the REM may have potential for monitoring tropical ungulates particularly in dense evergreen forest where other methodologies, for example, distance‐based line transect sampling are unsuitable.

Assessing changes in the above ground biomass and carbon stocks of Lidder valley, Kashmir Himalaya, India

The changes in the land use and land cover (LULC), above ground biomass (AGB) and the associated above ground carbon (AGC) stocks were assessed in Lidder Valley, Kashmir Himalaya using satellite data (1980–2013), allometric equations and phytosociological data. Change detection analysis of LULC, comprising of eight vegetation and five non-vegetation types, indicated that 6% (74.5 km2) of the dense evergreen forest has degraded. Degraded forest and settlement increased by 20 and 52.8 km2, respectively. Normalized difference vegetation index was assessed and correlated with the field-based biomass estimates to arrive at best-fit models for remotely sensed AGB estimates for 2005 and 2013. Total loss of 1.018 Megatons of AGB and 0.5 Megatons of AGC was estimated from the area during 33-year period which would have an adverse effect on the carbon sequestration potential of the area which is already facing the brunt of climate change.

Natural Forest Biomass Estimation Based on Plantation Information Using PALSAR Data

Forests play a vital role in terrestrial carbon cycling; therefore, monitoring forest biomass at local to global scales has become a challenging issue in the context of climate change. In this study, we investigated the backscattering properties of Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data in cashew and rubber plantation areas of Cambodia. The PALSAR backscattering coefficient (σ0) had different responses in the two plantation types because of differences in biophysical parameters. The PALSAR σ0 showed a higher correlation with field-based measurements and lower saturation in cashew plants compared with rubber plants. Multiple linear regression (MLR) models based on field-based biomass of cashew (C-MLR) and rubber (R-MLR) plants with PALSAR σ0 were created. These MLR models were used to estimate natural forest biomass in Cambodia. The cashew plant-based MLR model (C-MLR) produced better results than the rubber plant-based MLR model (R-MLR). The C-MLR-estimated natural forest biomass was validated using forest inventory data for natural forests in Cambodia. The validation results showed a strong correlation (R2 = 0.64) between C-MLR-estimated natural forest biomass and field-based biomass, with RMSE = 23.2 Mg/ha in deciduous forests. In high-biomass regions, such as dense evergreen forests, this model had a weaker correlation because of the high biomass and the multiple-story tree structure of evergreen forests, which caused saturation of the PALSAR signal.

PALSAR 50 m Mosaic Data Based National Level Biomass Estimation in Cambodia for Implementation of REDD+ Mechanism

Tropical countries like Cambodia require information about forest biomass for successful implementation of climate change mitigation mechanism related to Reducing Emissions from Deforestation and forest Degradation (REDD+). This study investigated the potential of Phased Array-type L-band Synthetic Aperture Radar Fine Beam Dual (PALSAR FBD) 50 m mosaic data to estimate Above Ground Biomass (AGB) in Cambodia. AGB was estimated using a bottom-up approach based on field measured biomass and backscattering (σo) properties of PALSAR data. The relationship between the PALSAR σo HV and HH/HV with field measured biomass was strong with R2 = 0.67 and 0.56, respectively. PALSAR estimated AGB show good results in deciduous forests because of less saturation as compared to dense evergreen forests. The validation results showed a high coefficient of determination R2 = 0.61 with RMSE = 21 Mg/ha using values up to 200 Mg/ha biomass. There were some uncertainties because of the uncertainty in the field based measurement and saturation of PALSAR data. AGB map of Cambodian forests could be useful for the implementation of forest management practices for REDD+ assessment and policies implementation at the national level.

Vegetation structure and greenness in Central Africa from Modis multi-temporal data

African forests within the Congo Basin are generally mapped at a regional scale as broad-leaved evergreen forests, with the main distinction being between terra-firme and swamp forest types. At the same time, commercial forest inventories, as well as national maps, have highlighted a strong spatial heterogeneity of forest types. A detailed vegetation map generated using consistent methods is needed to inform decision makers about spatial forest organization and their relationships with environmental drivers in the context of global change. We propose a multi-temporal remotely sensed data approach to characterize vegetation types using vegetation index annual profiles. The classifications identified 22 vegetation types (six savannas, two swamp forests, 14 forest types) improving existing vegetation maps. Among forest types, we showed strong variations in stand structure and deciduousness, identifying (i) two blocks of dense evergreen forests located in the western part of the study area and in the central part on sandy soils; (ii) semi-deciduous forests are located in the Sangha River interval which has experienced past fragmentation and human activities. For all vegetation types enhanced vegetation index profiles were highly seasonal and strongly correlated to rainfall and to a lesser extent, to light regimes. These results are of importance to predict spatial variations of carbon stocks and fluxes, because evergreen/deciduous forests (i) have contrasted annual dynamics of photosynthetic activity and foliar water content and (ii) differ in community dynamics and ecosystem processes.

Abundance changes and activity flexibility of the oncilla, Leopardus tigrinus (Carnivora: Felidae), appear to reflect avoidance of conflict

We investigated the density and activity of the oncilla, Leopardus tigrinus (Schreber, 1775), a threatened small cat, in the Brazilian Atlantic Forest, using camera-trap data. We described differences in the activity of individuals occurring alone or in sympatry with larger cats. Oncilla presented low densities (7-13 ind./100 km²) and high flexibility in its activity. The oncillas were primarily nocturnal in the absence of other larger cat species - margay, ocelot and puma - but became more diurnal, with a cathemeral activity pattern, when the other cats were present. Oncilla is likely to be in a subordinate position in interactions with larger cats and changes its activity to decrease the chances for interspecific encounters. In this study, however, the presence of other cat species covaries with habitat changes (from coastal forest patches to dense evergreen forests). We also verified the highest oncilla relative abundance in an area with no sympatric larger cats, with abundance decreasing when it was in sympatry with margay, ocelot and puma. Our results, together with recent records of oncilla in other degraded landscapes of the Atlantic Forest of Brazil, provide evidence that oncillas may thrive even in harsh environments where other cats have already been extinct. This raise interesting conservation insights, as in the absence of other cats, L. tigrinus may assume a top predator role of these impoverished vertebrate communities.

Tingidae (Insecta, Heteroptera) from the Argentinan Yungas: new records and descriptions of selected fifth instars

Guilbert É. & Montemayor S. I. 2010. — Tingidae (Insecta, Heteroptera) from the Argentinan Yungas: new records and descriptions of selected fi fth instars. Zoosystema 32 (4) : 549-565.The Yungas are an area of dense evergreen forests covering the eastern slopes of the Andes. Very few studies deal with the insects of this biotope. Here the results of a first study of the Tingidae (Insecta, Heteroptera) of these forests are presented. New distribution and records of species, as well as descriptions of the fifth instar larvae of Corythucha tapiensis, Dictyla monotropida, Gargaphia dissortis, Leptopharsa firma, Sphaerocysta angulata, Tigava pulchella are provided. The tingid fauna of the Yungas does not seem highly characteristic of this area, but it is poorly known, especially at high elevations.

Cover Picture: Steel Construction – Design and Research 4/2009

AbstractThe Norwegian Public Roads Administration (NPRA) is widening the existing European Route E6 from two to four lanes over the stretch from Oslo's main airport, Gardermoen, and north to Lillehammer, the city that hosted the Winter Olympics in 1994. In the middle of the stretch there is a major intersection offering a choice between Norway's two biggest valleys, Gudbrandsdalen and Østerdalen. And here, at this remote site, stands Kolomoen Bridge, deep within dense evergreen forest but visible from afar in three directions via the road corridors through the forest.

Ocorrência de Atelocynus microtis (Sclater, 1882) na Floresta Nacional do Jamari, estado de Rondônia

O cachorro-de-orelhas-curtas Atelocynus microtis é uma das espécies mais raras de Canídeos Sul-americanos. Os relatos são muito raros e a inexistência de animais cativos também sugere distribuição limitada e densidades baixas. No período de 16 de agosto a 12 de outubro de 2006, foi realizado um monitoramento fotográfico na Floresta Nacional do Jamari, que é uma Unidade de Conservação de Uso Sustentável e possui plano de manejo com seu zoneamento ambiental definido. Os registros fotográficos de Atelocynus microtis foram obtidos nas regiões centro-oeste e noroeste da unidade, áreas formadas por Floresta Ombrófila Densa, com pontos de Floresta Ombrófila Aberta. As áreas onde foram capturadas as imagens fotográficas de Atelocynus microtis, estão em Zona de Manejo Florestal e em Zona de Mineração, por enquanto sem exploração. A partir destes fatos, a sugestão seria que o zoneamento ambiental desta Unidade de Conservação levasse em consideração este achado e fosse alterado para que a espécie fosse mais bem estudada na região antes da exploração das áreas. Como estudos relacionados a esta espécie são praticamente inexistentes, esta nota se torna importante, contribuindo com dados sobre a ecologia do A. microtis.

Plant Species Diversity in the Southern Part of the Taï National Park (Côte d’Ivoire)

Plant species diversity is surveyed in the southern part of the Tai National Park (TNP), Cote d’Ivoire. This park is the largest remaining tract of pristine forest in the West African rainforest biodiversity hotspot. Plant assemblages and environment factors were surveyed in 39 temporary 625-m2 plots within three areas. The species list was completed thanks to itinerant prospections. TWINSPAN classification and detrended correspondence analysis were applied to the 39 releves. We recorded a total of 916 plant species, including 169 West African endemics, that rises the floristic richness of TNP in 1233 species. Most plant species recorded were Guineo-Congolian species (90.9%) among which 8% were ‘Sassandrian species’, i.e. endemics of the extreme southwest Cote d’Ivoire. Eight of these endemics were exclusive of the southern part of TNP. The forest is very species-rich, particularly in Rubiaceae, Leguminosae and Euphorbiaceae. Most of the sampled species (59.5%) were erect phanerophytes with a dbh≤10 cm. We distinguished 7 plant community types, mainly determined by geomorphology and disturbance history. Lowland forests were typical dense evergreen forests with different degrees of maturity related to historical human impact. Inselbergs and swampy depressions provide an original azonal vegetation. We conclude that the southern part of TNP contributes significantly to the regional biodiversity hotspot since it includes the last remnants of primary evergreen rainforest and contains species assemblages from both higher rainfall biomes on moist soils derived from schist parent material and lower rainfall biomes on inselberg slopes and top. As anthropogenic disturbance clearly reduces biodiversity, these last remnants should be integrally protected.

Estimation of aboveground biomass in logged and primary lowland rainforests using 3-D photogrammetric analysis

We estimated the total aboveground tree biomass (TAGB) in an old-growth primary forest and in a regenerating forest that had been selectively logged in 1958, both within the tropical rainforest of the Pasoh Forest Reserve in Peninsular Malaysia. This was achieved by comparing aerial photographs with data obtained previously from destructive sampling in the same area. Aerial photographs were taken above the primary and logged forest plots in 1997. The heights of the canopy-forming trees were estimated in both plots by means of aerial triangulation and were regressed against the diameter at breast height (DBH) of the corresponding trees measured during ground surveys. The resulting allometric relationship between tree height and DBH let us estimate TAGB: in the primary forest, TAGB was 310 Mg ha −1, which was ca. 10–12% smaller than the value estimated by means of destructive sampling conducted in the 1970s. The estimated TAGB of the logged forest was 274 Mg ha −1, which was significantly smaller than that of the primary forest ( P < 0.05). We also measured canopy surface height in a 2.5 m grid system. We found that the mean canopy surface height (MCH) in every 20 m × 20 m subplot (0.04 ha) was significantly ( P < 0.0001) correlated with TAGB for that subplot. This suggests that the spatial variation of TAGB can be estimated using MCH values obtained from such a grid system, and that biomass levels can potentially be estimated by means of satellite remote sensing on larger scales, even for very dense tropical forests. We also found that digital reflectance values from Landsat Thematic Mapper (TM) images differed significantly between the logged and primary forests, and hypothesize that these differences relate to structural differences in the canopy surface. However, TAGB in both plots was poorly correlated with the Landsat reflectance values, suggesting the necessity of using an active remote-sensing sensor or a laser profiling system that can quantify changes in the forest's vertical structure or volume to estimate biomass and its variation in dense evergreen forests.

Régénération des espèces ligneuses en forêt du Parc national d'Odzala (Congo-Brazzaville)

This study is deeling with the regeneration of woody species in three types of Marantaceae forest in the Odzala national Park: the dense evergreen forest, the scattered Marantaceae forest and the Marantaceae bush. The basic data were collected from two different groups of plots:—three plots of 0.5 ha each for the inventory of trees of dbh (diameter at breast height) ≥ 5 cm; three plots of 5 ha each for those of dbh ≥ 30 cm. Analysis of specific structure for 13 species has pointed out good regeneration in dense forests and poor regeneration in Marantaceae bush. This is in accordance with the regeneration deficit density which varies from dense forest to Marantaceae bush. The inhibitor impact of high density of Marantaceae on species regeneration is pointed out and confirmed to be in question as for as the regeneration jamming within the scattered Marantaceae forest is concerned. We have noted a diminution of the plantules species density of the dense forest to Marantaceae bush and an increase of the Marantaceae density in the two forest types respectively.

Nonhuman primates in the Namdapha National Park, Arunachal Pradesh, India

Namdapha National Park and Tiger Reserve in the Changlang District of Arunachal Pradesh in northeastern India are rich in biodiversity. The dense evergreen forest of the park with high canopy coverage supports a variety of fauna including primates. In February, 2002, we surveyed the primates in Namdapha National Park to assess their status. We directly sighted, 5 species of diurnal primates, and secondary information shows the presence of stump-tailed macaques and slow lories. We encountered 10 groups of hoolock gibbons (33 individuals), 9 troops of capped langurs (61 individuals), 15 groups of Assam macaques (209 individuals), 6 groups of rhesus macaques (74 individuals) and one unidentified group of macaques (≤15 individuals). Hunting, rather than habitat destruction, is the chief potential threat for primates in the park.

Application of multiscale texture in classifying JERS-1 radar data over tropical vegetation

In this paper, a multiscale texture-based classifier for mapping tropical forest land cover types is discussed. The classifier was implemented using the Japanese Earth Remote Sensing Satellite (JERS-1) 100 m resolution radar data acquired over the Amazon Rainforest as part of the Global Rainforest Mapping (GRFM) Project. Demonstrated here is the use of the information content present in different texture measurements at different scales to separate three categories of land cover types: forest from nonforest, terre firme from floodplain vegetation, and grassland from woodland savanna. Various combinations of first-order image statistics known as texture measures were used at different scales as feature dimensions to aid the class discrimination. Eight of the most common first-order texture measures found in the literature were used. The best combination of texture measures at each scale were determined by employing a class separability test using the Bhattachuryya distance. The results were then used as input images into a supervised multiscale maximum likelihood estimation classifier. The classified maps were validated against independent test sites, and by comparison with a Landsat Thematic Mapper (TM) classification. It was found that JERS-1 backscatter and texture measures can discriminate forest from nonforest types with very high accuracy (above 90%). Old secondary forest or regrowth areas were often mixed with forest. Radar backscatter alone was able to separate terre firme and floodplain vegetation. However, texture measures were important in separating open from dense floodplain vegetation. Similarly, the backscatter sensitivity to low biomass values was instrumental in separating woodland from grassland savanna. Texture had a lesser role in separating these two vegetation types but was important to separate the woodland savanna from dense evergreen forest and secondary forests.

Composition floristique et structure des formations à Garcinia lucida dans la région de Bipindi-Akom II (Sud-Cameroun)

The Bipindi-Akom II region in South-Cameroon belongs to the Biafran atlantic district of the Guineo-congolian domain of dense humid evergreen forests. Inside this vegetation unit, Garcinia lucida is a remarkable understorey gregarious species, growing in low-lying ground and on slope of some hills. Four localities in which this species occurs have been sampled and 36 common species have been identified forming the floristic composition of such plant community. Representative species are, in addition to Garcinia lucida, Treculia obovoidea, Coelocaryon preussii and Raphia regalis. The analysis of the different strata showed that Garcinia lucida is the main dominant species at the shrub layer. No dominant species have been found at the tree layer. The population structure in the four localities indicates the stability of these formation but also the low occurence of emergent trees inside these Garcinia lucida facies.

Description of the leaf deer (Muntiacus putaoensis), a new species of muntjac from northern Myanmar

AbstractIn May 1998, an expedition into northern Myanmar obtained detailed descriptive data on a new species of muntjac called the leaf deer, first discovered on a survey the previous year and characterized primarily by its diagnostic DNA compared to other muntjac species. Weights, measurements, and physical data were obtained from 12 freshly killed leaf deer, along with partial measurements from 90 head pieces of leaf deer found in village huts. Except for the diminutive, unbranched antlers on males, averaging 3.2 cm long, older male and female leaf deer were similar in size and appearance, with average weights of 12.1 kg and 11.8 kg for males and females, respectively. When compared with other species, leaf deer are one of the smallest, and perhaps one of the most primitive, extant muntjacs. Two of the most distinguishing characteristics of this new species are the relatively long, equal‐sized canines in both older adult males (average 2.4 cm long) and older adult females (average 2.2 cm long), and the lack of spotting on the coats of a newborn and two juveniles estimated to be &lt; 2 months old. All older males (n= 3) and 40% of older females (n= 5) had healed wounds on one or both ears. These wounds, in addition to the large canines in both sexes, may indicate that females as well as males compete actively for resources. Although still relatively abundant throughout mid‐elevation dense evergreen forests, between the northern extremities of the Mai Kha and Mali Kha Rivers in north Myanmar, the currently known distribution of the leaf deer is outside any protected areas. Persistent hunting by local people with snares, dogs, and crossbows for a thriving market trade in deer leather, have caused noticeable decreases in numbers of leaf deer captured over recent years and could threaten the future survival of this new species.