A survey of the 1:100,000 topographic maps of Papua New Guinea revealed that there are about 5383 freshwater lakes in the country. They range in size up to 647 km2 but the majority are less than 10 ha. They are found at all altitudes to over 4000 m but most are situated below 40 m in the floodplains of the Fly, Sepik and Aramia rivers. The majority of lakes are undoubtedly shallow but depths range up to 360 m. The lakes were formed in at least 20 different ways but the majority by fluviatile action. The few data on chemical and physical conditions suggest that most lakes are chemically poor with low light penetration and low pH values. With the possible exception of the macrophytes the fauna and flora of the lakes are virtually unstudied, particuarly from a quantitative aspect. Most lakes are probably polymictic.

1211 trees of 3 ft (0.91 m) girth or more were enumerated in 288 1-ch2 (about 400 m2) quadrats forming a 11.7 ha plot on the mainly Segamat soil series, Jengka Forest Reserve, Peninsular Malaysia, in 1964. Of the 261 taxa, 84% were identified to species. Five per cent of the area was of the permanently wetter Akob soil series. The plot was topographically flat and lay about 3 km west of the plot on the Batu Anam soil series, described in an earlier paper. Data on the chemical composition of the three soils are summarized here from a survey in 1967.

The vegetation on the Segamat series is of the Shorea-Dipterocarpus type of lowland dipterocarp forest. It has an unusually high abundance of the Euphorbiaceae (25% of trees) and a clear dominant species, Elateriospermum tapos. E. tapos, which regenerates profusely in the shade, grows up in small gaps and is strongly clumped, and appears well suited to the very friable, relatively nutrient-rich soil of the Segamat series, with lower soil-water holding capacity especially in dry periods.

Forest on the Segamat series is floristically very different from that on the Batu Anam series. This is most likely due to large differences in soil properties, the latter being of lower clay content, less nutrient-rich and, having a greater soil-water holding capacity at least in dry periods. It was dominated by Dipterocarpaceae.

Classification of quadrats on the Segamat series highlighted four classes; vegetation of the main E. tapos-dominated type on relatively dry soil (54% of plot area), vegetation on the wet Akob soil (21%), an association of shade-tolerant, mainly understorey trees beneath non-E. tapos-associated emergents (11%), and an association of long-lived, light-demanding pioneer trees of late-successional stages (11%); 3% of plot had no enumerated trees. Ordination showed that the plot was largely homogeneous with respect to edaphic factors but clearly displayed stages in forest succession.

The possible dynamics of the Segamat forest are inferred in terms of species autecology. Two hypotheses are advanced to explain the composition of the Segamat forest: (a) a dynamic equilibirum, (b) a non-equilibrium recovery from a recent catastrophe. The latter was thought more likely. Compared with the more benign Batu Anam environment, where co-dominants might be ‘ecologically equivalent’, the more selective soil conditions on the Segamat leads to reduced equivalence, with accidents of regeneration playing a smaller role in the local distribution of the most abundant species.

To up-date and extend knowledge of the Akure Strict Natural Reserve an assessment, block by block, of forest in the core of the Inviolate Plot was undertaken in 1974 and complemented with soil sampling. Principal components analysis indicated a gradient of soil reaction and available phosphorus through the core of the plot. Ordination (DECORANA) of floristic data revealed that a floristic trend paralleled the soil trend. In the vicinity of a drainage line, at the western end of the core, soils were lower in available phosphorus, more acid, sandier and texturally more uniform with depth. Typical trees of ferralsols were prominent on these soils but were replaced by species of ferric luvisols, especially members of the Sterculiaceae, on soils of superior nutrient status towards the eastern end. It is suggested that the soil gradients were not effects produced by the trees.

Comparison of a 1946 data set with the 1974 data supported the view that the forest had been structurally and floristically stable over the interval between assessments. This is considered justification of the original choice of the area as a Strict Natural Reserve representative of high forest in this part of Nigeria.

The study was conducted in tropical lowland forest in the Dumoga Bone National Park, Sulawesi, Indonesia. It sought (a) to establish the typical densities of sap-sucking Hemip tera, (b) to quantify the intensity of Hemiptera feeding on leaves, and (c) to investigate, using multivariate techniques, the relationships between Hemiptera density and/or feeding damage and a range of leaf or plant characteristics. Only 3% of shrubs examined had colonial Hemiptera feeding on growing shoots. Feeding punctures on leaves were common but the insects which produced them such as the Cicadellidae and various Heteroptera were scarce. Coccoidea and Aleyrodoidea were the dominant and ubiquitous Hemipterans, feeding primarily on the surface of the leaves. Psylloidea were relatively rare and Aphidoidea were not recorded. For the complete data set, which included all leaves examined, there were few significant correlations, either singly or in combination, between the various measures of insect abundance and the state of the 17 leaf characteristics recorded. However, when the data for young leaves were extracted there was evidence to suggest that the number of feeding punctures cm−2 of leaf and the number of coccids cm−2 of upper leaf surface increased rapidly to a maximum as the young leaf aged and certain characters changed accordingly. Other more stable leaf characteristics such as hairiness, spininess, glossiness, etc. explained only a small additional amount of the total variance in Hemiptera abundance.