Atmospheric gains and hydrologic losses of calcium, magnesium, potassium, phosphorus and nitrogen for 25 tropical forest sites on a variety of geological substrates are reviewed. The data set comprised 19 lowland and six montane sites. Twenty studies were subjected to further analysis after initial quality control. These were subdivided into forests on (1) very infertile soils (N = 5), (2) (moderately) infertile soils (N = 5), (3) moderately fertile soils (N = 4) and (4) fertile soils (N = 4). Two studies pertaining to large river basins were treated separately. Although variation in nutrient fluxes was large, reflecting both natural and methodological factors, scatter plots of annual calcium, magnesium and potassium losses v. annual runoff for small catchment areas revealed four groups with characteristic nutrient export patterns that corresponded closely with soil fertility levels. Element losses from the two large basins were much higher than those recorded for small basins in the same areas and were interpreted in terms of depths of weathering front, river incision and root network. Phosphorus accumulated in virtually all cases, reflecting the low mobility of the element. Nitrogen budgets were generally very incomplete. There is a need for more and careful studies of tropical forest nutrient budgets, especially for nitrogen. Standardization of methodology is essential if comparability of results is to be improved.

Data on the laxonomic composition of the arboreal arthropod fauna of 10 Bornean lowland rain forest trees are presented, based on samples obtained using insecticide fogging. Combined samples from all trees comprised 23,874 individuals of at least 3000 species. The mean number of species on each tree was 616.7 with one tree sample containing more than 1007 species. The relative rank of the major orders of arthropods in terms of both species and individuals was remarkably constant across the trees. Hymenoptera, Coleoptera, Diptera and Hemiptcra were the orders with the most species and individuals. Formicidae, though not particularly species rich, was the most abundant family in terms of individuals and the commonest species in six of the 10 trees was an ant. Refogging of one of the trees 10 days after initial sampling showed that the arthropod fauna had not completely recovered. What many arthropods are doing in the canopy is discussed.

A population of Garra ceylonensis in a rocky, hill stream was studied by monthly sampling over a period of two years. The monthly population density, which varied from 1.28 to 4.16 m-2 with a mean of 2.37 m-2, was negatively correlated with the water speed. Asymptotic length (L∞) and the growth constant (K) were found to be 180.5 mm total length and 0.62. Maximum size observed was 174 mm, which is attained in about five years, but 99% of the population had a life expectancy of less than 3.4 years. The overall male to female ratio of the population was 0.58. The sex ratio was 1.0 in smaller size classes but decreased steadily with increasing size. There was a major spawning season following the main rainy period in contrast to the trend of most tropical freshwater fish species, which show enhanced breeding during the rainy season. The mean length and age at sexual maturity in females appear to be 109 mm and eighteen months. Fecundity varied between 740 and 4390. Average longevity and natural mortality were 4.8 years and 1.86. The mean biomass, average annual production and turnover ratio of the population were about 23.7 gm-2 wet weight, 41.2gm-2 and 1.7, respectively.

Bird species were surveyed in a variety of habitat types in a lightly populated area of western Brazilian Amazonia. Habitats surveyed were untagged forest, selectively logged forest, ‘capoeira’ (scrub regenerating on cleared land), cropfields, and an isolated 35 ha forest ‘island’. All habitats were within a few kilometres of each other. Many bird species were found to occur in all or most habitats, although the similarlity of the species assemblages dropped with increasing levels of disturbance of the natural vegetation. Certain understorey insectivores common in untagged forest were rarely observed in other habitats; disturbed areas contained higher numbers of flycalching insectivores or birds feeding on both insects and fruit, some of which were open-country rather than forest species. The avifauna of the forest ‘island’ was more similar to that of regenerating scrub than to that of tall forest, and the persistence of forest species was attributed to their ability to move to and from nearby continuous forest areas.

In May and June of 1989 data on elephant (Loxodonta africana) dung density were collected in the main forested areas of the Central African Republic. A total of 147.0 km of line transects (N = 14 transects, = 10.50 km, SD = 3.79) was completed. Dung was recorded in 37.4% of the 294 sectors of 0.5 km each. The overall dung density was estimated to be 266 piles km-2 (= 382, SD = 383.7). The highest dung density was found in the proposed Dzanga-Sangha Reserve in the extreme south-west with 1166 piles km-2 (N = 12 sectors of 0.5 km). The south-eastern forests were found to have an intermediate dung density of 336 piles km-2 (N = 215 sectors of 0.5 km, = 419, SD = 308). In the eastern section of the south-western forests no dung was recorded along survey transects (N = 67 sectors of 0.5 km). These data indicate that elephant populations are still relatively high in the forests of south-western and south-eastern Central African Republic, while the population in the eastern section of the south-western forests has diminished to a very low level.

The frails of Cola lizae, an endemic tree with a limited geographical distribution, have been a major food source for lowland gorillas in the Lopé Reserve during part of each year over a six-year period. Faecal analysis indicated that 11,000-18,000 Cola seeds km-2 were deposited by gorillas during the 4-month season in 1989. Gorillas are the only important dispersers of this species: other primates consume the succulent mesocarp, but do not swallow the large seed; elephants do not eat Cola fruits. Observations of Cola seeds in gorilla faeces showed a very high germination rate and, despite initial high mortality, 18% of seedlings still survived six months after deposition. Survival of seedlings was significantly better in faeces left at nest-sites than in other areas of the forest: 40% of seedlings were viable at nest-sites six months after deposition. This suggests that the open areas of forest, preferred by gorillas as nest-sites, are advantageous to the propagation of this species.

A comparative analysis of earthworm populations in seral Khasi pine forest represented by Pinus kesiya 5- and 35-year old stands, and a climax broad-leaved mixed forest represented by a sacred grove was done at altitudes of 1500 m in Meghalaya in north-east India. Tonoscolax horaii occurred under all forest types whereas Amynthas diffringens and Eulyphoeus feslivus were confined to pine forest stands only. Perionyx sp. and Drawida assamensis were restricted to the sacred grove. T. horaii had larger numbers in all three different forest types. This species offers possibilities of vermicullurc for biologically improving soil fertility in manmade ecosystems because of its wide range of tolerance.

Generally earthworm populations were more active during the monsoon season; A. diffringens was however, more active during the winter, thereby conferring an advantage on this species as it was enabled to avoid competition during the monsoon season when other species dominate. Earthworm activity was generally higher in the sacred grove than in the pine forest stands. Population size was significantly correlated with soil moisture, temperature and pH. Wormcasts had a higher pH and nutrient status than the soil.

In the highly leached soils of the humid tropics where there is a large concentration of fine root biomass in the surface soil layers, earthworm activity is beneficial because it helps incorporate detritus into the mineral soil rapidly and locally concentrates nutrients in the surface layers.

An assessment of carnivore species richness and food habits was carried out in a 100 km2 area of dry tropical forest in Huai Kha Khaeng Wildlife Sanctuary, Thailand. Twenty-one carnivore species of five families were found to be feeding on at least 34 mammal species, as well as birds, lizards, snakes, crabs, fish, insects, and fruits. Forty-four percent of the prey identified in faeces of larger carnivores, primarily leopards, consisted of barking deer, Muntiacus muntjak. Sambar deer, macaques, wild boar, porcupine, and hog badger were important secondary prey items. In faeces from small carnivores (< 10kg), murid rodents accounted for 33% of identified food items. The two most frequently encountered mammalian prey species were the yellow rajah rat, Maxomys surifer, and the bay bamboo rat, Cannomys badius. Non-mammal prey accounted for 21.3%, and fruit seeds for 12.4%, of all food items found in small carnivore faeces.

Using data from forest sites in Sarawak, East Malaysia, a demographic comparison is made of pioneer species in the genus Macaranga with understorey trees of the primary forest in the closely related genus Mallotus. In primary forest, saplings and trees of these genera arc uncommon and have low growth rates. For the six years following disturbance by logging, a Macaranga population was characterized by high rates of diameter growth and recruitment. Eleven years after disturbance, seedling and sapling abundance had declined sharply. In contrast, the Mallotus population was stable in size class distribution and increased slightly in total population size during the 11 years after logging. Growth rates of Mallotus trees increased after logging but were still much less than Macaranga trees.

A morphological comparison shows that most Macaranga species, in contrast with Mallotus species, have large hollow twigs that are occupied by ants and have larger, hairier, thicker, more toothed leaves with longer petioles, axillary inflorescences with more flowers, infructescences with more fruit, fruits that are smaller in size and smaller seeds.

Litterfall was sampled during one year in two undisturbed Andean forests at altitudes of 2550 and 3370 m in the Colombian Cordillera Central. Total small litterfall at 2550 and 3370 m was 7.03 and 4.31 tha-1 y-1 respectively, of which 4.61 and 2.82 were leaves, 1.06 and 0.76 woody parts, 0.66 and 0.27 reproductive parts, 0.22 and 0.23 epiphytes, 0.47 and 0.23 unclassified.

Clear differences were also found in nutrient concentrations, both between different litter fractions from one site and between equivalent litter fractions from different sites. Weighted mean concentrations for total small litterfall were (mgg-1, at 2550 and 3370m respectively): 11.7 and 7.3 for nitrogen; 0.86 and 0.44 for phosphorus; 8.4 and 3.1 for potassium. Comparison of nutrient concentrations in crown leaves and shed leaves indicated important reallocation of nitrogen (39% at both sites) and phosphorus (45% at 2550m, 65% at 3370m) before leaf shedding.

The results for litterfall amounts, litter nutrient concentrations and reallocation of nutrients in the two forests are consistent with such data obtained in other montane forests in the wet tropics.

The dispersal of seeds by howler monkeys (Alouatta palliata) and the activity of dung beetles in modulating the fate of the dispersed seed were studied at Los Tuxtlas, Mexico. Howlers consumed the fruits of 35 species of plants. The seeds of 28 of these were dispersed by the monkeys. The majority (≥90%) of the seeds dispersed by monkeys were destroyed by rodents. Rapid relocation and burial of dung by dung beetles resulted in accidental relocation and burial of large numbers of seeds shortly after deposition. Faecal clumps (20 mg) remained on the ground for an average of only 2.5 h (range 1–3 h). Ball rolling beetles transported balls up to 5.0 m from the site of deposition (range 1–5 m). Burrowing and ball-rolling dung beetles buried seeds at depths ranging from 2.5 to > 12.0cm. The deeper a seed is buried, the less likely it is to be found and eaten by rodents. Eighty percent of the species used by Alouatta as sources of fruit at Los Tuxtlas benefited by the dispersal and post dispersal service provided by howlers and dung beetles respectively. Seasonality in dung beetles abundance in the forest may influence the number of seeds per species escaping post-dispersal predation during the year. Dung beetles play not only an important ecological role in the recycling of matter and energy in the ecosystem, but also in the process of rain forest regeneration.

Leaf litter production by lianes (=lianas) and trees was compared in an evergreen rain forest in subtropical Australia. Several successional stages were represented at the main site. Lianes contributed 2.2% of total basal area (69.6 m2 ha-1) of this site, but 24% of leaf litterfall (5.9–6.5 tha-1 y-2 over two years. Minor year-to-year variation in litterfall was attributed to incidence of severe storms, and drought. Lianes were responsible for about 17% of leaf litterfall in spring, 21% in the summerpeak, and 40% in autumn, more lianes than trees being deciduous. Leaf litter production by 23 individual species of liane, in relation to their basal area within the main site, was, on average, 15 times as great as that by 34 tree species, but declined more steeply between the species-groups of early and later succession. Tendrillar lianes, unlike twiners and scramblers, were confined to the ‘early’ successional group, and their foliage was spread across canopy surfaces, maximizing light interception. It was concluded that this contributed to greater production of leaf litter, per unit basal area, by tendrillar than by other climbers, and to the successional decline in leaf litterfall from lianes.

Nanophyes shoreae is a pre-dispersal fruit-predator of several species of Dipterocarpaceae. The timing of oviposition of this weevil was monitored in six trees in Pasoh Forest Reserve, West Malaysia from September 1986 to February 1987. A flowering event occurred during this period. Oviposition started within 12 days after peak anthesis, and continued within any one tree for 11–39 days. Host trees of N. shoreae flowered over a 75 day period. Intra-specific flowering synchrony was high but different species flowered sequentially. The behaviour of N. shoreae and the period of the oviposition ‘window’ strongly suggest that this pre-dispersal fruit-predator ‘tracks’ the sequence of flowering shown by its host species. The implications for predator satiation through mass-flowering of the Dipterocarpaceae are discussed.