Samples of 29 distinct larval forms of anurans were collected in streams flowing through primary rain forest at Nanga Tekalit, Sarawak, at three periods spaced over 22 years. This assemblage of tadpoles lives in torrents, riffles, shingle areas, open pools, leaf drifts, protected side pools, potholes in rocky banks, bank seepages, and pools of small intermittent streams. Positive associations of species in types of microhabitats and co-occurrence within sites lead to recognition of four taxonomically heterogeneous groups: one concentrated in leaf drifts; one using riffles, shingle areas, and open pools; one concentrated in potholes; and one using side pools and potholes. Most pairs of larval forms having strong negative association are characterized by differences in morphology and feeding behaviour; they show little evidence of competitive relations. Between-sites variation in species composition differs among the types of microhabitats, leaf drifts showing the least amount of variation. Species composition within a site shows less change over intervals of 1–5 days than over intervals of 13–18 days. Variation in species composition is greater between sites than within sites over intervals of 9–31 days. Organization in this community seems to be effected by three factors: reproductive behaviour of adults and morphological and behavioural adaptations of tadpoles.

Concentration of CO2, above and below the soil surface and δ13C values of plant tissues, soil litter and organic matter were measured in a caatinga forest of the upper Rio Negro basin in southern Venezuela. CO2, concentrations near the forest floor were consistently higher than in the atmosphere. CO2, gradient in the soil was very steep probably because of the poor aeration in this flood-prone forest. δ13C values of plant tissues showed a clear pattern with lower values in the ground herbaceous plants and under-canopy trees. Tree seedlings showed δ13C values similar to the upper-canopy trees indicating their dependence on reserves carried in the seed from the mother tree. Decomposing litter and soil organic matter also showed δ13C values similar to the upper-canopy trees. It is suggested that lower δ13C values of the shade flora result primarily from the assimilation of CO2, depleted in δ13C originating from soil respiration. Probable effects of low light intensity and physiological factors are discussed.

Plant and soil samples collected from four tropical forest areas were used to examine the correlation between the chemical abundances in soil and vegetation. On fertile soils in Panama and Colombia soil concentrations of copper, manganese, cobalt and zinc were correlated with plant concentrations. Calcium, caesium, iron, lead, magnesium, phosphorus, potassium, sodium and strontium-concentrations were not correlated. Factor analysis of plant chemistry at nine sites showed very little commonality between sites, even of vegetation belonging to the same plant association. A copper, manganese, cobalt, zinc factor was not recognized except in one case. A similar study of plant soil correlation in Colombia supported the conclusions from Panama; for most elements there was little evidence for significant correlation between plant and soil concentrations.

Analysis of plant-soil relationships on very infertile latosols with terra firme forest in the Amazon at San Carlos de Rio Negro, Venezuela and Manaus, Brazil revealed a soil effect on the statistical distributions of the elements in the plant biomass. This effect was strongest on the least fertile site at Manaus and was strongest for essential elements. The pattern of chemical distributions appears to be due to the fact that some species are capable of concentrating high levels of elements even under conditions of very low supply in the substrate.

‘Times Species-counts’ are a simple method of comparing the avifaunas of extensive areas by sampling representative habitats. The method has been evaluated in south central Kenya but could be applied to most terrestrial regions of tropical Africa. The essential feature is that the observers move anywhere within a sample site of about 1 km2, recording all of the species seen in a fixed time, e.g. 1 h.

Counts are made in all seasons and at various times of day. Reasonable estimates of the total number of species in an area can be derived from a series of 15 counts, but such estimates tend to be low in non-forested habitats because ‘wanderers’ (non-resident species) continue to be recorded almost indefinitely. Open sites have far fewer species than well-wooded areas. The numbers of resident species in non-forested terrestrial habitats is related both to the amount of woody vegetation and to a measure of plant growth. However, total species numbers seem to depend solely on the amount of woody vegetation. Road counts, from a vehicle, were compared to those made on foot. They are less satisfactory, especially for cryptic species.

In January 1983, two 50 m × 50 m rain forest plots in the University of Ife campus in southwestern Nigeria were demarcated for a baseline study of species composition, litterfall and tree girth increments. By accident, a severe ground fire burnt one of the plots on 31 January, barely two weeks after litter traps had been set and species listing and first girth measurements completed.

The effect of this fire was assessed in the burnt plot after 14 months, in April 1984. The fire affected small trees especially, and there were indications that some species were more sensitive than others.

Manihot glaziovii, which was present in the plot and abundant in its vicinity before the fire showed a big increase in density after the fire because it was able to germinate in the openings created by the fire. These observations were related to succession, and it is concluded that the observation by some workers that the initial composition of a regrowth forest may be partly predicted from a knowledge of the seed bank in the soil may be applicable in the present case.

Community patterns along a successional sequence of abandoned fields within a tropical rain forest environment are described in terms of floristic composition and structure. Temporal patterns were summarized and main axes of variation extracted by multivariate methods.

External factors – length of cropping period, regrowth age, and proportion of the perimeter occupied by forest communities or remnants (here called forested perimeter) – were related to floristic and structural data on 40 sites. Multivariate direct gradient analysis showed overall floristic development to be positively related to regrowth age and forested perimeter, and negatively related to length of cropping period.

Structural development was shown by multiple regression to be positively related to regrowth age and negatively to length of cropping period; but forested perimeter had no significant relation to site structure. The type of crop grown showed no significant relation with floristic or structural development of the regrowth.

These results indicate that the conditions of the vegetation around a site have a great effect on community recovery, particularly in its species composition, whilst structure seems to be affected more directly by parameters which imply time.