Colonization of gaps produced by death of bamboo clumps in a semideciduous mesophytic forest in south-eastern Brazil

The study was carried out in 16 gaps produced by bamboo clump death (Merostachys riedeliana Rupr. ex Doell) in a semideciduous mesophytic forest in the Santa Genebra County Reserve (22°4945 S and 47°0633 W), Campinas, SP, south-eastern Brazil. All shrub and tree individuals in the gap with height 0.50 m were sampled. The floristic similarity among the colonizing vegetation in these gaps and in gaps produced by treefall was assessed by the Jaccard similarity index and cluster analysis. The colonization process of these gaps was found to be similar to that in gaps formed by treefall, but this colonization only began after the bamboo clump death. The gap area varied from 35 m² to 454 m², but small gaps predominated. In the set of gaps, 3677 individuals were sampled belonging to 40 families, 83 genera and 114 species. The families with the greatest species richness in the gaps were Myrtaceae (10), Euphorbiaceae (9) and Solanaceae and Rubiaceae (8 each). The species with the greatest number of individuals in the gaps were the pioneers Celis tala Gillies ex Planchon and Croton priscus Muell. Arg. and the shade-tolerant shrubs Actinostemon klotschii (Muell. Arg.) Pax, Polygala klotzschii Chod., Psychotria hastisepala Muell. Arg. and Galipea multiflora Engl. Late secondary species predominated because of the greater number of small gaps. The gaps formed by bamboo clump death contributed to the successional and structural organization of the forest, creating suitable environments for colonization by shrub and tree species of the different successional groups.     

Leaf dynamics of seedlings of rain forest species in relation to canopy gaps

Summary Leaf dynamics of eight tropical rain forest species seedlings was studied in three environments: the shaded forest understorey, a small gap of ±50 m², and a large gap of ±500 m². Leaf production rate and leaf loss rate were enhanced in gaps, and a large gap resulted in larger increases than a small gap. For most species net leaf gain rate was larger in gaps, although this rate was not always largest in the large gap. Leaf loss decreased, and leaf survival percentages increased with increasing shade tolerance of species, indicating a slower leaf turnover for more shade tolerant species. Leaf area growth rate was only partly determined by net leaf gain rate. Ontogenetic effects on leaf size were also important, especially in the large gap. Species which possessed leaves with high specific leaf weight (SLW) showed lower leaf loss rates and higher leaf survival percentages than species with low SLW leaves. Leaf life span seemed to be related to leafcost per unit area. The relation of specific patterns in leaf production and leaf loss to the regeneration mode of the species is briefly discussed.     

The effect of canopy gaps on growth and morphology of seedlings of rain forest species

Summary Growth and morphology of seedlings of ten tropical rain forest species were studied at Los Tuxtlas, Mexico. Seedlings were grown in three environmental conditions: the shaded forest understorey (FU, receiving 0.9–2.3% of the daily photosynthetic photon flux, PF, above the canopy), a small canopy gap of approx. 50 m² (SG, receiving 2.1–6.1% of daily PF), and a large canopy gap of approx. 500 m² (LG, receiving 38.6–53.4% of daily PF). The growth of all species was enhanced in gaps, and in LG the effect was stronger than in SG. Plants grown in LG had a sunplant morphology, with a high root-shoot ratio (R/S), a high specific leaf weight (SLW) and a low leaf area ratio (LAR). Plants grown in SG or FU showed a shade-plant morphology, with a low R/S, a low SLW and a high LAR. Growth responses varied from species unable to grow in the shade but with strong growth in the sun, to species with relatively high growth rates in both shade and sun conditions. Shade tolerant species were able to grow in the shade because of a relatively high unit leaf rate. The pioneerCecropia had a high growth rate in LG because of a high LAR. Most species showed a complex growth response in which they resembled the shade intolerant extreme in some aspects of the response, and the shade tolerant extreme in other aspects.     

Tree species richness complementarity, disturbance and fragmentation in a Mexican tropical montane cloud forest

Tropical montane cloud forest exhibits great heterogeneity in speciescomposition and structure over short geographic distances. In central Veracruz,Mexico, the conservation priority of seven cloud forest fragments was assessedby considering differences in woody plant species richness and complementarityof species among sites, forest structure, tree mortality, and timber andfirewood extraction as indicators of anthropogenic disturbance. Densities oftrees 5 cm dbh (360–1700 trees/ha) weredifferent among the sites, but basal area (35.3–89.3m²/ha) did not differ among fragments. The number of dead trees rangedfrom 10–30 to 170–200 trees/ha. The fragments'species composition was different but complementary. The Morisita–Hornindex indicated low similarity between fragments. A non-parametric estimator ofspecies richness indicated that more sampling effort would be necessary tocomplete the inventory (15 additional trees and two understory shrub species).Unfortunately, most of the fragments are threatened with deforestation. The numberof cut trees was similar among sites (0–15 cut trees/0.1 ha).Sites with immediate need for conservation were close to settlements, with highnumbers of cut trees and no legal protection. The selected sites represent thevariety of situations that exist in the region. Given the high complementarityobserved between fragments, a regional conservation approach will be required topreserve the last repositories of part of the tremendous biodiversity of theonce continuous forest in this region.     

Formation and closure of canopy gaps in the rain forest at Nouragues, French Guiana

Formation and closure of canopy gaps was monitored for three years in 12 ha of primary rain forest at Nouragues, French Guiana. At the first inventory, in April 1991, 74 openings in the canopy > 4 m² (sensu Brokaw 1982a) were located; 60 of these gaps were formed before January 1990. Between January 1990 and December 1993, 5 to 15 gaps were annually formed, opening 0.64–1.33% of the forest canopy each year. Of all gaps, 41% were created by a falling, snapped tree, 34% by a falling, uprooted tree, 22% by a falling branch, and 3% by a falling dead stem. A refined nearest neighbour analysis showed that gaps formed after January 1990 were clustered: uprooting of trees seemed to be related to shallow soils, and relatively many other trees fell when a tree uprooted, independent of the dbh of the uprooted tree. In 37 gaps, canopy openness in the gap centre (determined by hemispherical photographs) was monitored over three years. In 54% of the gaps, canopy openness increased in two successive years. It is reasoned that edges of especially large gaps may frequently be re-disturbed by falling trees or branches. Results suggest that gaps have closed after around 15 years. More data are needed to verify this.     

Leaf demography and leaf traits of temperate-deciduous and tropical evergreen-broadleaved trees in a Mexican montane cloud forest

The spatial variation in epilithic lichen community structure was investigated as part of a larger study of the vegetation and ecology of the tall limestone cliffs within the Niagara Escarpment Biosphere Reserve in southern Ontario, Canada. The cover of all lichen taxa was visually estimated for a total of 199 samples taken from the top, middle, or bottom of the cliff face at five sites. Twelve environmental variables were also measured. Twenty-seven lichen taxa were identified on the samples. Multivariate ordinations of species composition (DCA, CCA, PCCA) revealed variation in community structure on multiple scales, but no groupings of sites that would have suggested the presence of several distinct species assemblages. A gradient in species composition from north to south, most clearly reflected in the decreasing cover of foliose and fruticose species, may reflect a gradient in human disturbance. There was also intermediate-scale patchiness in species composition in a horizontal plane across cliffs, but despite earlier claims made in the literature, no evidence of vertical zonation of the lichens on cliffs was found. Species composition also responded to small-scale factors possibly related to exposure, light, or moisture. Unlike community composition, the total cover of all lichens was homogeneous over large spatial scales and varied only on a small scale, illustrating that scale as well as resolution of a study may influence the ecological patterns seen. More than half of the species found on the Niagara Escarpment are rare on rock substrates elsewhere in southern Ontario, and two are new for North America (Candelariella heidelbergensis (Nyl.) Poelt and Lecanora perpruinosa Fröberg). The result that cliffs support a distinct flora containing many rare species suggests that they are a reservoir for biodiversity not just for vascular plants, but also for lichens.     

Size distribution and expansion of canopy gaps in a northern Appalachian spruce-fir forest

Canopy gap area/age distributions and growth mechanisms were examined in a virgin subalpine forest in the White Mountains, New Hampshire, USA. The gap area distribution was negative exponential in form. Whithin gap tree ages varied widely in response to stepwise gap expansion caused by windthrow of peripheral trees or death of standing mature Picea rubens at gap edges. As a consequence, the density of small gaps may have been underestimated and the density of large gaps overestimated. The estimates of canopy turnover time, 303 yr, and of patch birth rate on an area basis, 3.3×10^-3 ha new patches/ha land area/yr, were not affected by the gap expansion phenomenon. However, any estimate of patch birth rate as numbers of new patches formed per year would have been too low. Because of increasingly widespread Picea death, the patch area/age distribution of this forest may not currently be in steady-state.     

Rare canopy species in communities within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil

Rare species are one of the principal components of the species richness and diversity encountered in Dense Ombrophilous Tropical Forests. This study sought to analyze the rare canopy species within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil. Six different communities were examined: Dense Ombrophilous alluvial Forest; Dense sub-montane Ombrophilous Forest; Dense Montane Ombrophilous in Serra do Mar and Serra da Mantiqueira. In each area the vegetation was sampled within forty 10 × 25 m plots alternately distributed along a linear transect. All trees with DBH (1.3 m above ground level) ≥5 cm were sampled. The canopy was characterized using the allometric relationship between diameter and height, and included all trees with BDH ≥10 cm and height ≥10 m. A total of 64 families, 206 genera, and 542 species were sampled, of which 297 (54.8%) represented rare species (less than one individual per hectare). The percentage of rare species varied from 34 to 50% in each of the different communities sampled. A majority of these rare trees belonged to the Rosidae, and a smaller proportion to the Dilleniidae. It was concluded that there was no apparent pattern to rarity among families, that rarity was probably derived from a number of processes (such as gap formation), and that a great majority of the rare species sampled were consistently rare. This indicates that the restricted geographic distribution and high degree of endemism of many arboreal taxa justifies the conservation of even small fragments of Atlantic Forest.     

海南岛热带山地雨林种类组成的局域分布与垂直分布

对海南岛四大山地雨林区常见植物种类的局域及垂直分布进行了研究,结果表明,海南岛热带山地雨林的种类组成,除了在各林区有一定数量相同的种外,各林区之间种类成分也存在着显著的差异,由于各林区生态因子的差异,使得生态幅度不同的物种在垂直方向上的分布也产生明显的差异,生态幅度较小的物种仅局限于某一地段,生态幅度较广,适应性较强的种类则有较广泛的分布。     

Structure, distribution of species and inundation in a riparian forest of Rio Paraguai, Pantanal, Brazil

A phytosociological study was conducted in a riparian forest of the Rio Paraguai near Corumbá and Ladário in the state of Mato Grosso do Sul, Brazil. The topographic distribution of species was correlated with durations of the river's seasonal floodings and the cumulative time of flooding between 1974 and 1995. One hundred and eight contiguous 10×10 m plots were systematically established. All individuals with more than 15 cm of girth at breast height (gbh=1.3 m) were sampled. A total of 695 individuals distributed among 37 species, 35 genera and 23 families were found. The Shannon index (H′) for species diversity was 2.7. The highest importance value (IV) was found for Inga vera ssp. affinis, followed by Triplaris gardneriana, Ocotea diospyrifolia, Crataeva tapia and Vochysia divergens. The plots were classified into two groups according to their distance from the margin, applying Ward's method of classification and principal coordinate analysis (PCO) on the same Bray Curtis distance matrix. The topical environments were divided into four bands by Two-Way Indicator Species Analysis (TWINSPAN), and the species were also grouped into four groups. Flooding in these groups ranged from regular inundation in all 23 years of the historical series of the Ladário gauge to sporadic flooding for a maximum of 2 consecutive years.     

Relationship between vegetation structure and microenvironment in Fagus grandifolia subsp. mexicana forest relicts in Mexico

Aims Changes in the structure and composition of forests, whether caused by natural or anthropic events, alter the microenvironment, sometimes irreversibly. Since the local environment has a direct impact on basic ecological processes, this has become a key component of research. Mexican beech forests (Fagus grandifolia subsp. mexicana) in the Sierra Madre Oriental are restricted to sites with specific climate, soils and topography, making them an ideal natural system for ecological research. The objectives of this study were to identify the relationship between the microenvironment and the tree and shrub structure and composition of Mexican beech forests in the state of Hidalgo, and to compare the floristic similarity of these forests on the country scale using data from seven localities.Methods Specimens were collected for a period of one year at all localities in the state of Hidalgo where beech forests are located. At each locality, five 400 m 2 plots were established, and structural attributes (basal area, coverage, density and species richness) and six environmental variables were measured in the plots. The relationship between structure and microenvironment was estimated by simple correlation and canonic correspondence analysis (CCA). In addition, floristic similarity between different beech forest localities in the Sierra Madre Oriental was estimated by correspondence analysis (CA).Important findings Twenty tree species and eight shrub species were identified; at all localities studied F. grandifolia subsp. mexicana dominated the canopy. The multivariate analysis indicated that (i) in the four localities in the state of Hidalgo, all microenvironmental variables except pH are related to the variation observed in species composition and structure; (ii) the El Gosco locality had both tree and shrub species and microenvironmental factors different from those observed in the Fagus forests at the other localities in the study and (iii) the localities studied in order to draw country-scale comparisons could be divided into three groups by floristic similarity. The first group consisted of the Hidalgo localities, the second of the Veracruz localities, and the third, more different from the others, of the Tamaulipas locality. The results of this study provide the first reference for the relationship between the range of microenvironments and species structure in Mexican beech forests. Microenvironmental conditions in the larger beech forests could be used as a model for designing management and conservation programs for this plant association. Because of its particular ecological and historical characteristics, this association could serve as an example of biodiversity conservation in Mexico.     

Tree species composition and diversity of tropical mountain cloud forest in the Yunnan, southwestern China

Species composition, physiognomy, and plant diversity of the less known cloud forests in Yunnan were studied based on data collected from 35 sample plots at seven sites. In floristic composition, the cloud forests are mainly comprised of Fagaceae, Ericaceae, Vacciniaceae, Aceraceae, Magnoliaceae, Theaceae, Aquifoliaceae, Illiciaceae, Lauraceae, and Rosaceae. Physiognomically, the forests are dominated by tree and shrub species. Lianas are rare in the forests. The plants with microphyllous or nanophyllous leaves comprise 44.32–63.46% of the total species, and plants with an entire leaf margin account for more than 50% of the tree and shrub species. There are few tree and shrub species with a drip tip leaf apex and papery leaves. Evergreen species make up more than 75% of the total tree and shrub species. In a 2,500 m² sampling area, the number of vascular species ranged between 57 and 110; Simpson’s diversity index ranged from 0.7719 to 0.9544, Shannon–Winner’s diversity index from 1.8251 to 3.2905, and Pielou’s evenness index from 0.5836 to 0.8982 for trees. The cloud forests in Yunnan are physiognomically similar to the tropical cloud forests in America and Southeast Asia. They very much resemble the mountain dwarf mossy forest in Hainan Island, southeastern China, and the Mountain ericaceous forests in the Malay Peninsula. The cloud forests in Yunnan are considered to be developed, as are the tropical upper montane cloud forests in Asia.     

Understory development in canopy gaps of pine and pine-hardwood forests of the upper Coastal Plain of Virginia

Canopygaps are important in establishing a pool of natural regeneration in manytemperate forest ecosystems. Information on the role of gaps in loblolly pine(Pinus taeda L.) and pine-hardwood foreststands in the southeastern Coastal Plain of the United States is lacking.Accordingly, 12 small canopy gaps in mature pine and pine-hardwood standsin Petersburg National Battlefield, Virginia, were studied. Loblolly pineregeneration was significantly more abundant in canopy gaps as compared to theadjacent forest in both forest cover types. In four stands dominated by loblollypine, there were 750 saplings/ha in the gaps compared to only 125saplings/ha in the adjacent forest. Pine saplings dominated the regenerationspectrum in the gaps in the pine stands, while red maple (Acerrubrum L.) was more important in the adjacent forest. In fourpine-hardwood stands, regeneration in both the gaps and adjacent forestwas dominated by sweetgum (Liquidambar styracifluaL.) with importance values of 27% and 28%, respectively.There were no loblolly pine seedlings in the adjacent forest, but an average 313per ha in the gaps of the pine-hardwood stands. Within thegaps in both cover types, loblolly pine saplings were lower in stature thancompeting hardwood stems, leading to the conclusion that the gaps may form atemporary pool of pine regeneration. Without further stand disturbance, theprocess of gap closure may reduce the pine component to a secondary status, orperhaps eliminate it altogether.     

塔河源荒漠河岸林群落物种组成、结构与植物区系特征

为了更好地了解荒漠河岸林植被动态与生物多样性维持机制,于塔里木河干流源头荒漠河岸林内建立6个1 hm 2样地,对群落物种组成、数量特征和空间格局等进行综合分析。结果表明,塔河源荒漠河岸林群落结构简单、物种多样性低,共有物种12科15属16种,杨柳科重要值最大(28. 97%),是群落优势建群科。取样面积在0. 04 hm 2时,包括了87. 5%的物种;样地内稀有种和偶见种均占所有物种的12. 5%。植物区系贫乏,单种科、属多,温带成分占绝对优势,古地中海成分也占有重要地位,具典型温带区系性质。样地内 DBH ≥ 1 cm 的活木本个体有2497株,灰胡杨多度占92. 95%,胸高断面积和重要值最大,在群落中占绝对优势地位。群落内科、属、种的数量随植株高度级的增加而减少,垂直结构层次分明,由乔木层、灌木层和草本层构成。样地内所有树种平均胸径15. 57 cm,径级与高度级结构均呈偏正态分布,缺乏高度≤ 2 m的个体,群落更新不良。优势种灰胡杨、胡杨径级结构均呈单峰型,其中胡杨幼树出现断层,灰胡杨幼苗向幼树发展过程中死亡率极高(92. 56%),均为衰退型种群。两个优势种空间格局呈聚集分布,不同生境下随径级增大空间分布格局变化不同;且两个优势种在空间上相互排斥而占据不同生境,暗示着种间竞争与生境异质性是影响荒漠河岸林物种空间分布格局和物种共存的重要因素。     

Soil-vegetation relationships in cerrado (Brazilian savanna) and semideciduous forest, Southeastern Brazil

Several studies pointed out soil properties as the prime determinant ofcerrado (the Brazilian savanna) physiognomies, and a gradient from campocerrado (a shrub savanna) to cerradão (a tallwoodland) has been correlated with a soil fertility gradient. Based on thishypothesis, we investigated soil-vegetation relationships in thePé-de-Gigante Reserve (São Paulo State,SoutheasternBrazil). We randomly distributed 10 quadrats (10 × 10 m) oneach ofthe following physiognomies: campo cerrado, cerradosensu stricto, cerradão, andseasonal semideciduous forest, previously defined by the analysis of satelliteimages (LANDSAT-5). We sampled the woody individuals with stem diameter> 3 cm at soil level, identifying their species. In each quadrat, wecollectedsoil samples at the depths of 0–5, 5–25, 40–60, and80–100 cm, and determined pH, K, Ca, Mg, P, Al, H + Al, basesaturation, aluminium saturation, cation exchange capacity, and percentage ofsand, clay and loam. Obtained data were submitted to a canonical correspondenceanalysis (CCA) and to a detrended correspondence analysis (DCA). Our resultsshowed a clear distinction between semideciduous forest and the cerradophysiognomies, based in soil parameters. The former was related to higherconcentrations of cations and clay in the soil, while the latter was related tohigher concentrations of exchangeable aluminium in the soil surface. The threecerrado physiognomies – campo cerrado, cerradosensu stricto, and cerradão– could not be distinguished considering plant density and the analysedsoil features.     

Changes in tree and liana communities along a successional gradient in a tropical dry forest in south-eastern Brazil

We investigated changes in species composition and structure of tree and liana communities along a successional gradient in a seasonally dry tropical forest. There was a progressive increase in tree richness and all tree structural traits from early to late stages, as well as marked changes in tree species composition and dominance. This pattern is probably related to pasture management practices such as ploughing, which remove tree roots and preclude regeneration by resprouting. On the other hand, liana density decreased from intermediate to late stages, showing a negative correlation with tree density. The higher liana abundance in intermediate stage is probably due to a balanced availability of support and light availability, since these variables may show opposite trends during forest growth. Predicted succession models may represent extremes in a continuum of possible successional pathways strongly influenced by land use history, climate, soil type, and by the outcomes of tree–liana interactions.     

塔河源荒漠河岸林群落物种组成、结构与植物区系特征

为了更好地了解荒漠河岸林植被动态与生物多样性维持机制,于塔里木河干流源头荒漠河岸林内建立6个1 hm²样地,对群落物种组成、数量特征和空间格局等进行综合分析。结果表明,塔河源荒漠河岸林群落结构简单、物种多样性低,共有物种12科15属16种,杨柳科重要值最大（28.97%）,是群落优势建群科。取样面积在0.04 hm²时,包括了87.5%的物种;样地内稀有种和偶见种均占所有物种的12.5%。植物区系贫乏,单种科、属多,温带成分占绝对优势,古地中海成分也占有重要地位,具典型温带区系性质。样地内DBH ≥ 1 cm的活木本个体有2497株,灰胡杨多度占92.95%,胸高断面积和重要值最大,在群落中占绝对优势地位。群落内科、属、种的数量随植株高度级的增加而减少,垂直结构层次分明,由乔木层、灌木层和草本层构成。样地内所有树种平均胸径15.57 cm,径级与高度级结构均呈偏正态分布,缺乏高度≤ 2 m的个体,群落更新不良。优势种灰胡杨、胡杨径级结构均呈单峰型,其中胡杨幼树出现断层,灰胡杨幼苗向幼树发展过程中死亡率极高（92.56%）,均为衰退型种群。两个优势种空间格局呈聚集分布,不同生境下随径级增大空间分布格局变化不同;且两个优势种在空间上相互排斥而占据不同生境,暗示着种间竞争与生境异质性是影响荒漠河岸林物种空间分布格局和物种共存的重要因素。     

Population dynamics of the epiphytic bromeliad Tillandsia butzii in cloud forest

Epiphytes are a major component of tropical montane cloud forests. Over-exploitation and forest loss and degradation affect remnant populations. In this study, we analysed the population dynamics of the epiphytic bromeliad Tillandsia butzii over a 2-y period in a tropical montane cloud forest fragment in southern Mexico. Matrix analysis revealed that the T. butzii population is likely to be stable at the study site. On average the λ value did not differ significantly from unity: λ (95% confidence interval) = 0.978 (0.936–1.001). λ was highly influenced by stasis, to a lesser extent by growth and only slightly by fecundity. Overall, adult plant stasis and phalanx growth habit played a fundamental role in population maintenance. T. butzii tolerance to xeric conditions may contribute to population stability in the studied region.     

Photosynthetic acclimation of the liana Stigmaphyllon lindenianum to light changes in a tropical dry forest canopy

Tropical plant canopies show abrupt changes in light conditions across small differences in spatial and temporal scales. Given the canopy light heterogeneity, plants in this stratum should express a high degree of plasticity, both in space (allocation to plant modules as a function of opportunity for resource access) and time (photosynthetic adjustment to temporal changes in the local environment). Using a construction crane for canopy access, we studied light acclimation of the liana Stigmaphyllon lindenianum to sun and shade environments in a tropical dry forest in Panama during the wet season. Measured branches were randomly distributed in one of four light sequences: high- to low-light branches started the experiment under sun and were transferred to shade during the second part of the experiment; low- to high-light branches (LH) were exposed to the opposite sequence of light treatments; and high-light and low-light controls , which were exposed only to sun and shade environments, respectively, throughout the experiment. Shade branches were set inside enclosures wrapped in 63% greenhouse shade cloth. After 2 months, we transferred experimental branches to opposite light conditions by relocating the enclosures. Leaf mortality was considerably higher under shade, both before and after the transfer. LH branches reversed the pattern of mortality by increasing new leaf production after the transfer. Rates of photosynthesis at light saturation, light compensation points, and dark respiration rates of transferred branches matched those of controls for the new light treatment, indicating rapid photochemical acclimation. The post-expansion acclimation of sun and shade foliage occurred with little modification of leaf structure. High photosynthetic plasticity was reflected in an almost immediate ability to respond to significant changes in light. This response did not depend on the initial light environment, but was determined by exposure to new light conditions. Stigmaphyllon responded rapidly to light changes through the functional adjustment of already expanded foliage and an increase in leaf production in places with high opportunity for carbon gain. Received: 24 April 1998 / Accepted: 11 May 1999     

Site parameters,species composition,phytomass structure and element stores of a terra-firme forest in East-Amazonia,Brazil

Our objective was to asses site parameters, species diversity, phytomass structure and element stores of a Terra-firme forest prior to subsequent studies on nutrient fluxes during forest conversion. The soil was classified as a Xanthic Ferralsol, with a low effective cation exchange capacity (ECEC), low nutrient status and a deeply weathered solum. On 0.75 ha, including all trees with a DBH >7 cm, we identified 222 tree species belonging to 58 families. The above-ground phytomass was estimated using logarithmic regression analysis on two plots of 0.25 ha each. Despite differences in forest structure and species composition, no major differences were found in terms of total phytomass or overall element stores. The mean living above-ground phytomass (LAGP) was 257 Mg ha^–1, and mean quantity of litter 14 Mg ha^–1, while dead wood contributed between 10 to 17% of total above-ground phytomass (32–56 Mg ha^–1). Element store in LAGP was medium to high compared to other studies on tropical forest systems, while LAGP itself was comparatively low. Comparing 26 humid tropical forest stands recorded in literature, no correlation was found between LAGP and the amount of N and base cations stored in LAGP. However, a correlation between LAGP and P storage in LAGP (R ²=0.76) indicates the important role P may play in phytomass accumulation on zonal tropical soils. More then 60% of C, 20% of total N, 10% of total P and 66–88% of total K, Ca and Mg of the system (including the first meter of soil) were concentrated in the above-ground phytomass, including deadwood and litter. Consequently, phytomass destruction in form of forest conversion will lead to major element losses from the system.