Ecological Studies in Four Contrasting Lowland Rain Forests in Gunung Mulu National Park, Sarawak: I. Forest Environment, Structure and Floristics

Abstract

, has an area of 544 km2 and a wide range of rain forest formations on several soil types and at altitudes of 5G2376 m. It has an annual rainfall of about 5000 mm. (2) Sites of 1 ha were established in each of four contrasting types of primary lowland rain forest: alluvial forest (AF); dipterocarp forest (DF); heath forest (HF) and forest over limestone (LF). All trees (210 cm dbh) were measured for dbh and height, except for the LF where height was calculated using a regression equation based on height and diameter measurements of a sample of thirty-four trees. Estimates of numbers or biomass or both of small trees (< 10 cm dbh), lianes, ground herbs and ferns, and epiphytes (including ferns) < 3 m from the ground were also made. Epiphytes > 3 m from the ground and bryophytes were not ennumerated. The total above-ground forest biomass (t ha-' dry weight) was calculated as: AF, 250; DF, 650; HF, 470; LF, 380. (3) Leaf and branch material were collected from each tree and, as far as possible, identified to species. There were at least 223 species ha-' in the AF; 214 in the DF; 123 in the HF; and seventy-three in the LF. (4) Soil analyses were carried out using standard methods on twenty-five samples from each site. The A F soil was heterogenous, with gley soils of high base status in the lower, occasionally flooded, part and podzols and peats in the higher part. The D F soil was acid and very low in calcium. It was lower in total exchangeable bases than the very acid podzolic soils of the HF. The LF soils were shallow, highly organic, of high base status, and neutral to mildly acid pH. (5) It was demonstrated that the species-rich D F occurred on very poor soils but there was no simple relationship between soil nutrient element concentrations and biomass or species richness. Many factors are probably involved in controlling these attributes. (6) The causes of the distinctive sclerophyllous leaves of the heath forest are discussed. It is suggested that extreme soil acidity (in the absence of a buffering effect of Alt++) in the organic soils limits nitrogen mineralization and that low levels of biologically active nitrogen favour sclerophylly. Those features of heath forest which reduce transpiration may be important in reducing the mass flow of soil toxins to the root surfaces.

Structure, diversity, and spatial patterns in a permanent plot of a high Restinga forest in Southeastern Brazil

“…Th is result corroborates the connection between forest structure and soil properties suggested by Phillips et al (1994) and Uhl & Murphy (1981). Th e pattern found here was also found by other authors when comparing whitesand forests to other types of tropical forests (Proctor et al 1983;Davies & Becker 1996;Nebel et al 2001;Miyamoto et al 2003) and it is primarily due to the higher proportion of trees < 10 cm dbh and to the smaller proportion of large trees. In the PEIC plot the mean number of trees ≥ 60 cm dbh per hectare was six, whereas in other forest types it varied between eight and 33 trees (mean ± sd: 19 ± 7, Losos et al 2004).…”

“…Myrtaceae also deserves special mention because it harbored twice as many species as the second richest family of the plot. Th is pattern was not observed in other CTFS plots (Ashton et al 2004), or inventories of forests on white-sand soils in South America (Phillips & Miller 2002) and Asia (Proctor et al 1983;Newbery 1991;Davies & Becker 1996), where Myrtaceae does not exceed 7% of the total tree richness. However, nearby Atlantic Forest types have similar richness per family, with similar or higher Myrtaceae richness Guilherme et al 2004), suggesting an important eff ect of the geographic region on the general pattern of HRF fl oristic composition.…”

“…Common in South America and Asia, and known by several local names (e.g. heath forests, campinaranas, kerangas, varillal alto -Anderson 1981), white-sand forests develop on acid, sandy soils with low availability of nutrients (Proctor et al 1983;Ashton 2004;Luizão et al 2007). Th ese features act simultaneously to generate forests whose characteristics are shorter stature, lower species diversity, and roots more concentrated in the superfi cial soil horizons (Davies & Becker 1996;Miyamoto et al 2003;2007).…”

Produção de serapilheira em mata ciliar nativa e reflorestada no alto São Francisco, Minas Gerais

“…Os altos valores obtidos para a produção de serapilheira na mata ciliar nativa e reflorestada igualam-se somente aos altos registros obtidos por Golley et al (1978), Proctor et al (1986) e Pinto (1992 em matas ciliares localizadas em planícies aluvionares tropicais.…”

Produção de serapilheira em diferentes fases sucessionais de uma floresta subtropical secundária, em Antonina, PR

“…Representando uma ligação importante no ciclo orgânico de produção-decomposição, a serapilheira tem papel fundamental no funcionamento do ecossistema fl orestal (MEENTEMEYER et al, 1982). Dessa forma, seu estudo pode fornecer índices de produtividade da fl oresta, noções sobre taxas de decomposição e fenologia das espécies, além de permitir avaliar sua importância nos ciclos de nutrientes (CUNHA et al, 1993;DIDHAM, 1998;PROCTOR et al, 1983).…”