Tropical Semi-evergreen Forest Research Articles

Impact of Slash and Burning on Microbial Biomass in Semi-Evergreen Tropical Deciduous Forest of Manipur, North-East India

The impact of slash and burning on microbial biomass C, N and P in soils of semi-evergreen tropical deciduous forest were studied from February 1999 to January 2000. The experimental sites were located near Moreh town in the Chandel district of Manipur state (India) along the Indo-Myanmar border between 23° 49' N-24°28'N latitude and 93°45'E-94°16'E longitude. Microbial biomass C ranged from 319.50 ㎍ g/sup -1/ 905.50㎍ g/sup -1/ in the slash and burnt site and from 209.50 ㎍ g/sup -1/ to 708.80 ㎍ g/sup -1/ soil in the forest site. Microbial N ranged from 19.30 ㎍ g/sup -1/ to 99.45 ㎍ g/sup -1/ in the slash and burnt site and from 16.08㎍ g/sup -1/ to 88.90 ㎍ g/sup -1/ in the forest site. Microbial P varied from 10.90 ㎍ g/sup -1/ to 32.21 ㎍ g/sup -1/ in the slash and burnt site and from 2.50 ㎍ g/sup -1/ to 17.60 ㎍ g/sup -1/ in the forest site in different months throughout the year. Microbial biomass C, N and P were recorded to be higher in the slash and burnt site compared to the forest site The conversion of forest into slash and burnt site for agriculture - the traditional shilling cultivation practiced by tribal people in the north- eastern India leads to addition of large amount of organic matter in the soil thereby exhibiting higher values of microbial biomass C, N and P in the recent slash and burnt site than that of the forest site. Relationship between the soil moisture, soil organic C and microbial biomass C, N and P were found to be correlated significantly in both the sites.

A Rare Feeding Observation on Water Lilies (Nymphaea alba) by the Capped Langur (Trachypithecus pileatus)

The capped langur (Trachypithecus pileatus, Blyth 1843) inhabits a variety of forest types including tropical dry deciduous, subtropical, broad-leaf and dense evergreen hill forest with many streams, bamboo forest up to 2,000 m and teak and sal plantation forest areas [Srivastava, 1999; Majupuria, 1990]. The capped langur is diurnal and almost entirely arboreal, eating young and mature leaves, ripe and unripe fruits, flowers, seeds, bark and gum [Solanki and Kumar, 2002]. Stanford [1991, 1992], in his studies on feeding behaviours in Bangladesh, observed that, in the dry season, capped langurs survive on mature leaves, some seeds and bamboo shoots, occasionally feeding on gum and termite soil trails. We observed the feeding behaviour of this little known langur in Pakhui Wildlife Sanctuary, Arunachal Pradesh. The Sanctuary (26°54′–27°16′ N and 92°36′–93°09′ E) is located in the south-west of Arunachal Pradesh and is 861.95 km in area. The general vegetation type of the entire tract is classified as Assam Valley tropical semi-evergreen forest (2B/C1 of Champion and Seth [1968]). During a 1-year study on feeding and food preference of this langur, a rare feeding behaviour was observed in September 2002. A troop of capped langurs (consisting of 1 adult male, 4 females and two 9-month-old infants) was observed feeding on the stalks, leaves and flowers of the water lily Nymphaea alba. The monkeys spent most time feeding on the stalks, followed by the leaves of the lilies. Another interesting observation was that the 2 lactating females (who had infants) entered the water to feed on the water lilies so that their bodies were immersed in

Food preference of Rhesus Macaque Macaca mulatta during the pre-monsoon and monsoon season, Pakhui Wildlife Sanctuary, Arunachal Pradesh

Food preference of Rhesus Macaques (Macaca mulatta) in the wild was studied in semi-deciduou s and tropical semi-evergreen forest of Pakhui Wildlife Sanctuary in East Kameng District of Arunachal Pradesh, India during the pre-monsoon and monsoon seasons. A group of 25 Rhesus Macaques of different age and sex classes was observed. Data was collected using group scan method. Rhesus Macaques ate 25 plant species, with a preference for 10 species and the order of preference varied in different months. Highly preferred plant species were Udal (Sterculia villosa), Pipal (Ficus religiosa), Jutali (Altingia excelsa), Panijamun (Syzygium syzygioides) and climbers. The monkeys primarily fed on young leaves, mature leaves, fruits, flowers, flower buds, petioles and seeds during study.

FIRST RECORD OF THE YUCATAN DEER MOUSE, PEROMYSCUS YUCATANICUS (RODENTIA: MURIDAE) FROM GUATEMALA

Abstract We report the first record of Yucatan deer mouse, Peromyscus yucatanicus, in Guatemala. The Yucatan deer mouse was restricted to Yucatan Peninsula, where it is considered a common species in deciduous to semi-evergreen tropical forests, and secondary growth forests. Two Yucatan deer mice were collected at Laguna Flor de Luna, Laguna del Tigre National Park, Guatemala, on April 1999. This new record constitutes a range extension of 116 km south of the nearest previously known locality at Escarcega, Campeche, Mexico.

Leaf decomposition in two semi-evergreen tropical forests: influence of litter quality

Decomposition processes in tropical semi-evergreen forests are still poorly understood. The influence of soil properties and litter quality on decomposition rate was studied in two semi-evergreen forests of Guadeloupe, a forest plantation and a secondary forest, located on different soils. Leaf litter of four tree species was enclosed in litterbags for a 14-month period. Non-linear correlations were calculated between mass loss and the concentration of major leaf components (soluble C, N, lignin, cellulose, tannins, total soluble phenols) in order to determine the best predictor of leaf litter decomposition. Soil physico-chemical properties and ratios between some of the above-mentioned litter quality parameters were also examined as mass loss predictors. In addition, non-linear correlations were calculated between mass loss and litter quality parameters, at successive periods. Litter quality was the main determinant of litter decomposition in the studied forests. Several litter quality parameters were correlated with leaf disappearance, varying according to stages of decomposition. Between 1 month and 2.5 months, the mass loss was correlated negatively with the initial phenol content and with initial lignin:N and (lignin+phenol):N ratios. From 2.5 to 5.5 months, the mass loss was correlated negatively with the initial phenol content and positively with the initial cellulose content. At later stages of decomposition (9–14 months), the mass loss was correlated negatively with the initial tannin content. Differences in soil characteristics and fauna did not seem to be enough to affect decomposition.

History of Late Holocene vegetation at Quintana Roo, Caribbean coast of Mexico

A pollen record of a Late Holocene sediment core from the Mexican Caribbean coast (Quintana Roo) shows the development and changes of a mangrove system. Humid conditions seem to have persisted for the period approximately 2500–1500 14C yr BP (pollen zone I), and mangrove Rhizophora mangle dominated with a good representation of elements from the nearby semi-evergreen tropical forest. During the period approximately 1500–1200 14C yr BP (pollen zone II) the mangrove Conocarpus erecta dominated. R. mangle almost disappeared and other taxa appeared, suggesting drier climatic conditions and generally more open vegetation. This dry period coincided with the period of the Maya cultural decline. The following period (pollen zone III, approximately 1200–1000 14C yr BP) was characterized by the recovery of R. mangle, indicating more humid conditions than in the preceding pollen zone. Pollen zone IV (approximately 1000 14C yr BP till present) suggests a drier period reoccuring with C. erecta; this marks the transition to present day conditions.

Plant biodiversity and conservation of tropical semi-evergreen forest in the Shervarayan hills of Eastern Ghats, India

Species diversity, density, population structure and dispersion patterns of all trees and lianas (≥30cm gbh) were inventoried in a tropical semi-evergreen forest in the Shervarayan hills of Eastern Ghats, south India. Such data are necessary for ecosystem conservation of the under-studied Eastern Ghats, as extensive forests here have already been converted to coffee and orange plantations and the landscape changed due to aluminium ore mining and quarrying. Four 1-ha plots were established in Sanyasimalai (SM) reserve forest of the Shervarayan hills, one plot (SM1) located close to mining and quarrying area, two other contiguous plots (SM2 and SM3) located in selective felling area and the fourth (SM4) in a relatively undisturbed forest. These are 1 to 4km apart in the same semi-evergreen forest tract. In the four study plots a total of 3260 stems (mean density 815ha−1) covering 80 species in 71 genera and 44 plant families were recorded. Species richness was greatest in the undisturbed plot SM4 (50), while lowest (33) in the selectively felled site SM2. The forest stand (SM4) was also denser (986 stemsha−1) and more voluminous (basal area 44.3m2ha−1 as compared with the site mean of 35m2ha−1) than the other plots. Four trees, Chionanthus paniculata, Syzygium cumini, Canthium dicoccum and Ligustrum perrottetii dominated the stand, collectively contributing to >50% of the total density. Species richness and stand density decreased with increasing tree girths. The forest stand contained a growing population, but there was considerable variation in basal area distribution between the plots. Trends in species population structure varied, particularly for selective-felled species. Most species exhibited clumped dispersion of individuals both at 0.25ha and 1-ha scales. Variation in plant diversity and abundance are related to site attributes and human impacts.

Biomass of Rain Forest Mammals in the Lope Reserve, Gabon

1. Densities of mammals in five sites in lowland semi-evergreen tropical rain forest in the Lope Reserve, central Gabon, were estimated using standard line-transect methods. Biomass was calculated using weights taken from the literature. 2. The total estimated biomass of diurnal primates, ruminants, pigs, elephants and squirrels in the five sites varied between 998 and 5866 kg km −2 . Forest elephants (Loxodonta africana cyclotis Matschie) dominated the biomass in all sites, making up 52-89% and primates accounted for 6-30%. 3. Statistically significant differences in density were detected for most species in at least two of the sites. Some of these differences could be related to vegetation structure and composition, but the reasons for others were unclear

Man and climate in the Maya lowlands

A 15-m sedimentary core from Lake Salpeten provides the first complete Holocene sequence for the lowlying Peten District, Guatemala. Today, Lake Salpeten is a brackish, calcium sulfate lake near saturation surrounded by tropical semievergreen forest. The basal pollen record depicts sparse juniper scrub surrounding a lake basin that held ephermal pools and halophytic marshes. The lake rapidly deepened to > 27 m in the early Holocene and may have been meromictic, because nearly 2 m of gypsum “mush” was deposited. Mesic forests were quickly established and persisted until the Maya entered the district 3000 yr ago and caused extensive deforestation. Any climatic information contained in the pollen record of the Maya period is thus masked, but a regional pollen sequence linked to the archaeological record is substantiated because environmental disturbance was pervasive. Local intensification of occupation and population growth are seen as an increased deposition of pollen of agricultural weeds and colluviation into the lake, while the Classic Maya collapse is marked by a temporary decline in Compositae pollen. Effects of perturbations induced by the Maya persist in the pollen and limnetic record 400 yr after the Spanish conquest.

Comparison of floristic and structural classification of vegetation

A comparison is made between floristic and structural-physiognomic classifications of a tropical dry, semi-evergreen forest and thicket vegetation of south-eastern India. The classifications are strikingly similar in their main groupings which are ecologically meaningful; the differences between the classifications are virtually limited to allocation of some stands to different subcommunities. It is concluded that the use of structural-physiognomic criteria allows a detailed and ecologically significant classification of vegetation. Fairly advanced calculation facilities are necessary, however, to reach such a classification, since the structural-physiognomic differences between the resulting groupings are largely of a quantitative and not of a qualitative nature. This is a consequence of the general occurrence in all stands of the vegetation of the very great majority of the characters used in this study.