Rainforests Of Borneo Research Articles

The Flight Heights of Chalcid Wasps (Hymenoptera, Chalcidoidea) in a Lowland Bornean Rain Forest: Fig Wasps are the High Fliers1

Tropical rain forests are characterized by their rich plant diversity and highly diverse insect faunas containing mainly rare species. Phytophagous and parasitoid insects utilizing such fragmented resources often must travel considerable distances to find suitable hosts. For small, weak-flying insects, entry into the fast-flowing air above the canopy can provide one way by which long-distance dispersal is achieved. Using sticky traps placed at different heights in a lowland rain forest of Borneo, we compared the diurnal and nocturnal flight heights of chalcids, a group of mainly very small parasitoids and phytophages, to determine if the air above the canopy was used for dispersal. Most families were represented throughout the range of trap heights, including those above the general canopy. A higher proportion of individuals were trapped above the canopy at night than during the day. Fig wasps were exceptional in that they were trapped almost entirely above the canopy. They included species associated with host trees that do not fruit in the canopy, suggesting that these short-lived, slow-flying insects actively fly up above the canopy and then use the wind to passively carry them the long distances needed to reach their highly localized and ephemeral hosts. Once the fig wasps detect the species-specific volatiles released by their host figs, they then may fly down into the canopy, where the lower wind speeds would allow them to fly actively upwind to their hosts.

The Evolutionary History and Diversity of Australian Mammals

Palaeodiversity and relationships of all groups of Australian mammals are reviewed. The fossil record spanning this time is of variable quality. 'Dark Ages' about which nothing is known in terms of Australian mammal evolution include the late Triassic to late Jurassic, late Cretaceous to late Paleocene and middle Eocene to middle Oligocene. Very little is known about the early Cretaceous and late Miocene. The late Oligocene to middle Miocene record documents the highest levels of biodiversity known for the continent, comparable to that which characterises the lowland rainforests of Borneo and Brazil. Order Monotremata spans at least the last 110 million years and includes four families. The enigmatic Ausktribosphenos from 115 million-year-old sediments in Victoria may represent an archaic monotreme, specialised peramurid or previously undocumented order of mammals but is unlikely to represent a placental as suggested in the initial description. Order Microbiotheria is represented in the early Eocene (~55 mya) by two genera similar in morphology to early Eocene taxa from Argentina. Order Peramelemorphia spans the early Eocene to Holocene and includes at least five families. Order Dasyuromorphia spans at least the late Oligocene to Holocene and includes at least three families. Other dasyuromorphian-like marsupials are indeterminate in terms of family-level affinities. Order Notoryctemorphia spans the early Miocene to Holocene with one family. Order Yalkaparidontia spans the late Oligocene to middle Miocene with one genus. Order Diprotodontia spans the late Oligocene to Holocene, represented throughout by three major groups: Phalangerida (eight families), Vombatomorphia (seven families) and Macropodoidea (at least three families). A possible placental condylarth (Tingamarra) has been recorded from the early Eocene. An archaeonycteridid bat (Australonycteris) is known from the early Eocene. Among bats, the late Oligocene to middle Miocene is dominated by rhinolophoids, many of which have European, Asian and African affinities. Mystacinids, megadermatids, hipposiderids and molossids are well-represented in the Oligocene to Miocene deposits. Vespertilionids are uncommon in the Oligocene to Miocene but become more diverse in the Pliocene to Holocene. Emballonurids and rhinolophids appear for the first time in the Plio-Pleistocene. Pteropodids are unknown prior to the Holocene. Murids span the early Pliocene to Holocene. In the oldest assemblage at Riversleigh, one undescribed lineage resembles archaic forms otherwise only known from the fossil records of Africa and Eurasia.

Effects of 1997–1998 El Niño on tropospheric ozone and water vapor

This paper analyzes the impact of the 1997–1998 El Niño on tropospheric column ozone and tropospheric water vapor derived respectively from the Total Ozone Mapping Spectrometer (TOMS) on Earth Probe and the Microwave Limb Scanning instrument on the Upper Atmosphere Research Satellite. The 1997‐1998 El Niño, characterized by an anomalous increase in sea‐surface temperature (SST) across the eastern and central tropical Pacific Ocean, is one of the strongest El Niño Southern Oscillation (ENSO) events of the century, comparable in magnitude to the 1982–1983 episode. The major impact of the SST change has been the shift in the convection pattern from the western to the eastern Pacific affecting the response of rain‐producing cumulonimbus. As a result, there has been a significant increase in rainfall over the eastern Pacific and a decrease over the western Pacific and Indonesia. The dryness in the Indonesian region has contributed to large‐scale burning by uncontrolled wildfires in the tropical rainforests of Sumatra and Borneo. Our study shows that tropospheric column ozone decreased by 4–8 Dobson units (DU) in the eastern Pacific and increased by about 10–20 DU in the western Pacific largely as a result of the eastward shift of the tropical convective activity as inferred from National Oceanic and Atmospheric Administration (NOAA) outgoing longwave radiation (OLR) data. The effect of this shift is also evident in the upper tropospheric water vapor mixing ratio which varies inversely as ozone (O3). These conclusions are qualitatively consistent with the changes in atmospheric circulation derived from zonal and vertical wind data obtained from the Goddard Earth Observing System data assimilation analyses. The changes in tropospheric column O3 during the course of the 1997–1998 El Niño appear to be caused by a combination of large‐scale circulation processes associated with the shift in the tropical convection pattern and surface/boundary layer processes associated with forest fires in the Indonesian region.

Spatial structure and regeneration of Tetramerista glabra in peat swamp rain forest in Indonesian Borneo

We examined the spatial structure and regeneration of Tetramerista glabra, a dominant canopy tree in peat swamp rain forest in Borneo (West Kalimantan, Indonesia). T. glabra has strong spatial structure that changes dramatically during the life cycle; seedlings were highly aggregated, saplings were random and trees were evenly distributed. Germination and seedling relative growth were highest within canopy gaps, but seedling densities were highest at gap edges. Concentration of seedlings in gap edges, rather than localized seed dispersal, was responsible for seedling patchiness. The slope of the relationship between relative growth rate and seedling height decreased from gap, to gap edge to understory habitats, suggesting that competition within the seedling layer is more important in gaps than in the understory. The processes that break down seedling aggregation, leading to over-dispersion of trees, must be density dependent, but remain unknown.

Species richness and density of ground herbs within a plot of lowland rainforest in north-west Borneo

ABSTRACTIn a I-ha plot all ground herb species were recorded. Within the plot selected properties were investigated in three 20 m × 20 m subplots. The number of ground herb species and individuals in the subplots were lowest near to a local hilltop and they increased towards the lowest part of the plot. There was no significant difference in canopy openness, or in thickness of leaf litter layer, between the upper and lower subplots. In the upper subplot the soil layer was thin and the weathered bedrock was close to the surface. In the lower subplot the soil was much deeper. The pH and concentrations of Mg were significantly lower and %loss-on-ignition, total P and total N concentrations were significantly higher in the upper subplot. Elevation and soil moisture were significantly correlated in the upper 10 cm of soil. It is not possible to select any one abiotic property as being the critical determinant of the gradient of ground herbs. However, it is suspected that the availability of water in the topsoil, particularly after droughts, may be more important than the soil nutrients in limiting herb distribution.

Nomads of the Borneo Rainforest: The Economics, Politics, and Ideology of Settling Down

Nomads of the Borneo Rainforest: The Economics, Politics, and Ideology of Settling Down

REVIEW

Nomads of the Borneo Rainforest. The Economics, Politics and Ideology of Settling Down. By Bernard Sellato. Honolulu: University of Hawaii Press, 1994. Pp. xxiii + 280.

Nomads of the Borneo rainforest: the economics, politics, and ideology of settling down

Describes the process by which nomadic hunters of the Borneo rainforest have become sedentary and taken up subsistence farming and trading. Anthropologist Sellato has spent most of the past 20 years among the several groups, and emphasizes how the nomadic ideology survives to create a culture that i

Nomads of the Borneo Rainforest: The Economics, Politics, and Ideology of Settling Down. By Bernard Sellato. Translated by Stephanie Morgan. Honolulu: University of Hawaii Press, 1994. xxiii, 280 pp. $35.00.

Nomads of the Borneo Rainforest: The Economics, Politics, and Ideology of Settling Down. By Bernard Sellato. Translated by Stephanie Morgan. Honolulu: University of Hawaii Press, 1994. xxiii, 280 pp. $35.00. - Volume 54 Issue 2

Borneo Illipe, a fat product from differentShorea spp. (Dipterocarpaceae)

Fat extracted from kernels of Shorea spp. (Dipterocarpaceae) in the tropical rainforests of Borneo and Sumatra are traded under the name Borneo Illipe. The fat is used in chocolate formulations. The majority of kernels collected are fromShorea species in the sectionPachycarpae. Fat characteristics ofShorea species in this section show differences in fat quality in relation to its use as exotic sources in Cocoa Butter Equivalent (CBE) formulations. In order to comment on the future potential of the naturally occurring tree populations distribution maps of fiveShorea spp. involved in Borneo Illipe utilization are presented.

Rain forests of central Borneo—threatened by modern development

Rain forests in Central Kalimantan, Borneo, are under increasing pressure from commercial industry, agricultural projects and transmigration programmes. Our knowledge of the hill forests in central Borneo is virtually non-existent, yet they may disappear before we realize their true value as intact forests. These rapid developments prompted the FFPS to launch the Red Alert Project, which, together with Project Barito Ulu, is investigating ways to promote rain-forest conservation in Kalimantan, Indonesia.

Shuttle radar mapping with diverse incidence angles in the rainforest of Borneo

Abstract Shuttle Imaging Radar-B (SIR-B) images, obtained at two different incidence angles were analysed for discrimination and mapping of vegetation in the rainforest of Borneo. In an area of coastal lowland three units of forest canopy and two units of open surface cover were distinguished and mapped. The backscatter characteristics of the units were compared and analysed by ratioing digital image data of sample sites against digital data of reference sites. The ratios show that the backscatter for each surface unit is clustered in separate, mostly non-overlapping, domains at both incidence angles. Different rates of change with incidence angle indicate a strong angular dependence in the dominant backscatter mechanism of swamp that is not apparent for the other units. A corresponding digitally coregistered Landsat multispectral scanner (MSS) image helped to verify the spatial distribution of the mapped units in the coastal lowland. In the interior upland three major forest species associations that hav...

Reproductive Phenology of the Oak Family (Fagaceae) in the Lowland Rain Forests of Borneo

Seventeen individual trees of 12 species of Castanopsis, Lithocarpus, and Quercus were studied at 2-4 week intervals for most of a year, and reproductive phenology of numerous other individuals and species was recorded over a 3-year period. Inflorescence primordia were macroscopically visible near the end of the wetter season and anthesis of all flushes occurred in the drier season. There was general synchrony of reproduction among reproducing individuals, but a few trees were sterile throughout the observation period. Some had multiple reproductive flushes at 3-5 week intervals. Anthesis in the drier season by Castanopsis and Lithocarpus, which are entomophilous, maximizes pollination because that is the season of insect population peaks. Quercus is anemophilous and therefore is unaffected by insect population cycles. THE RECENT INCREASE IN KNOWLEDGE OF PHENOLOGY of tropical plants, especially those of the seasonal neotropics (Opler et al. 1976, Bawa 1983, Borchert 1983), is the most significant information to accumulate on tropical phenology. In Borneo and other paleotropical areas that are less seasonal, the phenologies are less understood, although definite seasonal rhythms are known for some tree species (Holttum 1940, 1968; Koriba 1958). According to Whitmore (1975), flowering and fruiting of most lowland Far Eastern tropical trees is periodic but regular and often annual; the Dipterocarpaceae, which are dominant over large areas, are noted for their infrequent but gregarious flowering. In his detailed taxonomic treatment of the Fagaceae of Malaysia, Soepadmo (1972) gave flowering and fruiting months for most species, but no dear patterns of regularity or synchrony emerge from that information. However, such patterns might appear locally. Observers in north-temperate dimates are familiar with the annual synchronous flush of leaves and flowers of Quercus (oak) and Fagus (beech) in the spring and Castanea (chestnut) in the summer; sometimes the fertile flush is followed by one or more sterile flushes. Phenology of the paleotropical Fagaceae is more complex. STUDY AREA AND METHODS In Borneo, the Fagaceae occur from sea level to about 3000 m and the largest number of species is found in the lower montane forests from 1200 to 1800 m elevation. The fagaceous trees are often gregarious in the mountains but are mostly scattered in the lowland forests. The three most extensive forest types in the Sarawak lowlands (our study area), are edaphically determined: mixed dipterocarp forest on silty day soils; semi-xerophilous heath forest on relatively infertile, sandy soils; and peat-swamp forests (Ashton 1965, Richards 1965, Briinig 1973). They contain 14, 21, and 5 fagaceous species, respectively (Briinig 1967). The mixed dipterocarp forest is the tallest, has the most tree species, and has irregular surface physiognomy; the Fagaceae occur as trees of the middle storey. The heath forest and peat-swamp forests are lower, less rich in species, and their canopies are more even (Anderson 1964; Briunig 1970, 1973). In them, the Fagaceae occupy mostly the middle and upper storeys. There is little seasonal temperature variation in the Kuching area of Sarawak (1?29'N, 1 10?10'E), the site of our observations. Daily maxima and minima average 310 and 22?C (Fogden 1972), and the annual variation in daily mean temperature is only about 2?C (Briinig 1969, 1971). The relative humidity seldom drops below 60 percent and is usually close to 100 percent in the forests (Fogden 1972). Day length varies by only 10 minutes throughout the year. Annual rainfall at Kuching is about 4000 mm, and all months have rain (Walter and Lieth 1967, Briinig 1969, Fogden 1972). The area has Sarawak's most variable rainfall and thirty-day periods of relative drought (with less than 100 mm) can occur from March until September (Briunig 1969, 1971). The heaviest rainfall is brought by the northeast monsoon from December through February (Fig. 1A), when all-day rains can occur; at other seasons rain is mostly from convectional afternoon I Received 27 March, revision accepted 26 September 1984. BIOTROPICA 18(1): 51-55 1986 51 This content downloaded from 207.46.13.120 on Wed, 14 Sep 2016 05:47:06 UTC All use subject to http://about.jstor.org/terms

On the Diversity of Reptile and Amphibian Species in a Bornean Rain Forest

Intensive collecting carried out over an entire year in 20 square miles of lowland rain forest in Borneo yielded 72 species of amphibians and reptiles considered to be regular inhabitants of the forest floor. Thirty-eight of these species, plus 12 that are "refugees" in the sense that they do not live primarily in this habitat, were collected in 402 quadrats randomly distributed over the forest floor. The average species diversity per individual was H' = 4.26 ± 0.21 bits, using Pielou's (1966a) method for estimating H' and its standard error from individual quadrats. This much diversity is equivalent to 28.3 hypothetical "equilibrium" species having relative abundances distributed according to the "broken stick" model of MacArthur (1957, 1960). The ratio of 28.3 to 84 (72 regular plus 12 refugee species) gives an "equitability" value (Lloyd and Ghelardi, 1964) of E = 0.34. Treating frogs, lizards, and "snakes" separately, we obtain diversity values of 3.30, 3.10, and 2.86 and equitability values of 0.47, 0.67, and 0.28 for the three groups, respectively. Although an equitability of E = 0.34 is well above the "ecological minimum" of E = 0.17 that would characterize 84 species having a lognormal distribution (Preston, 1962), it is surprisingly far below the "ecological maximum" of E = 1.0 that one would expect from the "equilibrium" community of a rain forest-a community rich in species, presumably having relatively constant, equable, predictable conditions for life. This leads us to re-examine the assumption that the rain forest floor environment is relatively constant and predictable. In respect of temperature it certainly is, but not so with rainfall. There is no dry season, but the spacing of heavy rainfalls (more than 1 inch in 24 hr) has an essentially random pattern. Rains of this intensity cause raging floods in the small streams in which many of the frog species breed. Conceivably this might often result in catastrophic mortality. The endless disturbance of intense rains may therefore prevent the community from achieving the theoretical equilibrium. Specimens obtained by general collecting were combined with those caught in the quadrats to form a total forest floor collection for this area of rain forest. Applying Pielou's (1967) method for partitioning diversity by taxonomic hierarchy, only a small part of the total species diversity (0.72 out of 4.65) is attributable to congeneric species living in the same habitat. This holds true also when frogs, lizards, and snakes are considered separately.