An Analysis of Four Tropical Rain Forest Sites in New Guinea

1966). Two of these forest types, forest on mid-slopes and forest on plateaux, were selected to investigate the interrelationship of structure, floristics and habitat in more detail by means of sample plots. Further objectives were to investigate the presence or absence of layering using detailed height and crown measurements, and to test the usefulness of profile diagrams. The results are thought to merit publication, firstly because quantitative information on tropical rain forest is rather scarce in the literature, and secondly because the findings are probably of more than local interest. The area visited lies in the Northern District of Papua, 100 miles (160 km) north-east of Port Moresby and about 18 miles (30 km) inland from the coast (Fig. 1). It comprises the southern foothills of the Hydrographers Range in the north, the northern foothills of the Sibium Range in the south, and a large central volcanic plateau, the Managalase. The area has a tropical rain forest climate and is subject to the north-west monsoon from December to March, and to south-east trade winds from May to October. Due to its position to leeward of the high east-south-east to west-north-west trending Owen Stanley Range in the centre of New Guinea, the area receives most rain during the north-west season. The nearest rainfall station, Popondetta, 12 miles (19 km) inland from the coast and about 500 ft (150 m) altitude, has a mean annual rainfall of 94 in. (2380 mm). As there is a general increase in rainfall with altitude and distance from the coast, the area under study probably has a higher rainfall. Monthly averages are most probably in excess of 4 in. (100 mm) even during the dry season. The area lies outside the zone of severe tropical storms but strong squall winds of up to 40 knots (74 km/h) have been observed (Fitzpatrick 1964).