Interdependence of peat and vegetation in a tropical peat swamp forest

The visual uniformity of tropical peat swamp forest masks the considerable variation in forest structure that has evolved in response to differences and changes in peat characteristics over many millennia. Details are presented of forest structure and tree composition of the principal peat swamp forest types in the upper catchment of Sungai Sebangau, Central Kalimantan, Indonesia, in relation to thickness and hydrology of the peat. Consideration is given to data on peat geochemistry and age of peat that provide evidence of the ombrotrophic nature of this vast peatland and its mode of formation. The future sustainability of this ecosystem is predicted from information available on climate change and human impact in this region.     

Amphibian species and functional diversity as indicators of restoration success in tropical montane forest

Tropical forest restoration is increasingly seen as an activity that may counteract or reduce biodiversity loss. However, few studies monitor fauna or consider measures of functional diversity to assess restoration success. We assessed the effect of a tropical montane forest restoration program on species and functional diversity, using amphibians as the target group. We compared amphibian assemblages in three types of land use: restoration areas, tropical montane cloud forest (TMCF; reference ecosystem) and cattle pastures (degraded ecosystem) in southern Mexico. We also described microclimate, microhabitat heterogeneity, woody vegetation structure and diversity for each type of land use, and their relationship to amphibian species and functional diversity. Compared to TMCF, restoration areas had similar environmental conditions. However, amphibian species richness was similar in the three types of land use and abundance was lower in the restoration areas. In TMCF, the amphibian assemblage was dominated by forest-specialist species, the pastures by generalist species, and the restoration areas by a combination of both species types. Interestingly, functional richness, functional evenness and functional divergence did not vary with land use, though the number of functional groups in restoration areas and TMCF was slightly higher. Overall, the results suggest that after seven years, active restoration provided habitat heterogeneity and recovered woody vegetation capable of maintaining amphibian species and functional groups similar to those inhabiting TMCF. Forest fragments adjacent to restoration areas seem to facilitate fauna recolonization and this emphasizes the importance of the conservation of the reference ecosystems to achieving restoration success.     

The contribution of leaching to nutrient release from leaf litter of two emergent tree species in a Malaysian tropical peat swamp forest

Ostracode faunas changed in Lake Bonneville as the lake rose in the closed basin and became more dilute, then overflowed, and eventually returned to closed-basin hydrology; alkalinity (carbonate + bicarbonate) increased throughout the lake history. Fossil-ostracode faunas in marl deposited in the lake between about 30 and 13 cal ka allow reconstruction of these geochemical changes (as shown by R. M. Forester), and permit stratigraphic correlations within the large lake basin, including into the Sevier subbasin, which was connected to the main body of the lake but had different inflowing rivers. The first ostracode to appear in Lake Bonneville deposits at low altitudes is Limnocythere staplini; it was replaced by L. ceriotuberosa as the lake got larger and the water became more dilute and alkaline. Candona adunca and several species of Fabaeformiscandona mark the freshest-water phases. Cytherissa lacustris appeared in lake-margin settings after lake level dropped and cold, fresh groundwater began to discharge into the lake. Candona sp. cf. eriensis lived in the Sevier subbasin during the transgressive phase of the lake, but did not appear in the main body until late in the regressive phase. Limnocythere sappaensis, which requires high alkalinity, showed up late in the regressive phase in the main body when lake level was very low.     

Electrophoretic and morphological comparisons in ten rain forest species of Shorea (Dipterocarpaceae)

Differences identified by electrophoretic separation of enzymes and other proteins are providing increasing informative for the study of evolutionary affinities within a genus. Zymogran compared with a scheme of putative affinities derived from a standard taxonomic classi based on consciously weighted morphological characters, as well as with indices of similarity on an array of morphological criteria relating to twigs, stipules, leaves, inflorescences and structure for 10 species of Shorea from southeast Malaysia. Shorea ovalis is placed in a separate of the genus from the other nine species; S. leprosula, S. parviflia and S. curtisii are related other on R^p data and a high degree of similarity is shown between these three spec S. dasyphylla .     

A comparison of sites suitable for the seedling establishment of two co-occurring species, Swintonia glauca and Stemonurus scorpioides, in a tropical peat swamp forest

Spatial and temporal ground-surface dynamics are major factors that affect regeneration and species coexistence in tropical peat swamp forests. We studied the seedling survivorship and morphological features of two tree species that play important roles in maintaining the ground-surface dynamics of a peat swamp forest in Sumatra. Large Swintonia glauca trees form mounds, whereas large Stemonurus scorpioides trees occupy non-mounds. We monitored the demography of naturally dispersed Swintonia and Stemonurus seedlings that germinated in 2000. Survivorship of Swintonia seedlings was high under conditions of late germination, high-light environment, and elevated ground surface, and was negatively affected by distance to the nearest conspecific adult. Survivorship of Stemonurus was high under conditions of early germination and high conspecific seedling density, and was also negatively affected by distance to the nearest conspecific adult. The allometric features of Stemonurus seedlings indicated characteristics of stress tolerance, that is, low growth rate and thick, porous roots. Stemonurus, which has large wingless seeds, regenerated in non-mounds around the parental trees, while winged Swintonia seeds dispersed farther from the parent and established in patchily distributed gaps and mounds. Thus, Swintonia seedlings can survive on non-mound sites within gaps and possibly create mounds, while Stemonurus seedlings tend to maintain non-mounds around the parental trees.     

Ecological and biogeographical effects of forest disturbance on tropical butterflies of Sumba, Indonesia

ABSTRACT. Butterfly assemblages within lowland monsoon forest were compared at four sites on Sumba, Indonesia that differed in terms of protection and exhibited associated differences in levels of human disturbance. A numerical method employing principal components analysis was devised for describing forest structure at each site. The first principal component (PRIN1) grouped attributes tending towards dense forest with closely-spaced trees, a closed canopy and a poorly developed field layer, with trees that tended to be large with the point of inversion in the upper half of the trunk. The highest values for PRIN1 were recorded within protected forest, and PRIN1 values were considered to be a useful index of forest disturbance at each site. Species diversity of butterflies was highest in unprotected secondary forest, but was not affected by lower levels of disturbance. Those species occurring at highest density in secondary forest generally had wide geographical distributions, whereas those species occurring at highest density in undisturbed primary forest had restricted ranges of distribution, in most cases with a separate subspecies on Sumba. Overall, an index of biogeographical distinctiveness decreased with increasing disturbance, and this supports the hypothesis that the most characteristic species of undisturbed climax forest have the smallest geographical ranges of distribution. Species abundance data for butterflies fitted a log-normal distribution at all but the most disturbed site. These results indicate that the pattern of proportional abundance of tropical butterfly species may be used as an ‘instantaneous’ indicator of forest disturbance, and that changes in the structure of tropical forests in S.E. Asia resulting from human disturbance, even within partially-protected forest, may result in the presence of butterfly assemblages of higher species diversity but of lower biogeographical distinctiveness, and therefore of lower value in terms of the conservation of global biodiversity.     

Adaptive significance of vegetative sprouting for a tropical canopy tree, Scaphium longiflorum (Sterculiaceae), in a peat swamp forest in Central Kalimantan

Scaphium longiflorum Ridley (Sterculiaceae), a common canopy tree in peat swamp forests in the Far East, produces vegetative sprouting in its juvenile stage. We investigated morphological features and allometric properties of the species in a peat swamp forest in Central Kalimantan, Indonesia, to determine under what conditions ramets are produced and discuss the adaptive significance of the vegetative sprouting in a peat swamp environment. Larger juveniles were more toppled, and the toppled ones sprouted vegetatively. Therefore, the vegetative sprouting acts as a countermeasure for a shoots mechanical failure and fall on an unstable peat soil. We propose three hypotheses to explain the reason why larger juveniles are more often toppled in a peat swamp environment.     

Population structure and demographic history of a tropical lowland rainforest tree species Shorea parvifolia (Dipterocarpaceae) from Southeastern Asia

Distribution of tropical rainforests in Southeastern Asia has changed over geo-logical time scale, due to movement of tectonic plates and/or global climatic changes. Shorea parvifolia is one of the most common tropical lowland rainforest tree species in Southeastern Asia. To infer population structure and demographic history of S. parvifolia, as indicators of temporal changes in the distribution and extent of tropical rainforest in this region, we studied levels and patterns of nucleotide polymorphism in the following five nuclear gene regions: GapC, GBSSI, PgiC, SBE2, and SODH. Seven populations from peninsular Malaysia, Sumatra, and eastern Borneo were included in the analyses. STRUCTURE analysis revealed that the investigated populations are divided into two groups: Sumatra-Malay and Borneo. Furthermore, each group contained one admixed population. Under isolation with migration model, divergence of the two groups was estimated to occur between late Pliocene (2.6 MYA) and middle Pleistocene (0.7 MYA). The log-likelihood ratio tests of several demographic models strongly supported model with population expansion and low level of migration after divergence of the Sumatra-Malay and Borneo groups. The inferred demographic history of S. parvifolia suggested the presence of a scarcely forested land bridge on the Sunda Shelf during glacial periods in the Pleistocene and predominance of tropical lowland rainforest at least in Sumatra and eastern Borneo.     

Gap-phase regeneration in a tropical montane forest: the effects of gap structure and bamboo species

To study the influence of gap structure and bamboo species on the regrowth of montane Atlantic forest, colonization by plants was characterized in 30 treefall gaps (30.3–500.5 m²). The study was conducted at Santa Virgínia (45°30 W, 23°17 S), a 4970-ha reserve of Atlantic montane forest in southeastern Brazil. Area covered by bamboos ranged from 0% to 100% of gap area. Average height of surrounding canopies ranged from 12 to 30 m. As gap are covered by bamboo and average height of surrounding canopies increased, both density and richness of pioneer woody species decreased. Density and richness of shade-tolerant species were negatively influenced by gap area. Low-light-demanding species of Miconia, Leandra and Rapanea accounted for the majority of both pioneer species and individuals sampled, whereas high-light demanding pioneers of Cecropia, Alchornea and Tibouchina were poorly represented. We suggest that in the Atlantic montane forest bamboo species compete for gaps, excluding other light-demanding pioneers. This results in an overall reduction of pioneer species richness in the Atlantic forest.     

Macaranga and Mallotus species (Euphorbiaceae) as indicators for disturbance in the mixed lowland dipterocarp forest of East Kalimantan (Indonesia)

The indicator value (IV) of Macaranga and Mallotus species (Euphorbiaceae) for different types of disturbance in lowland dipterocarp forest was assessed by counting and identifying all individuals of species of these genera taller than 30 cm in 45 (10 m×300 m) plots at nine locations. Twelve Macaranga and nine Mallotus species were found. The main forest disturbance types (primary forest, secondary forest, selectively logged forest, forest burned once, and repeatedly burned forest used for shifting-cultivation) each had their own set of indicator species. The level of disturbance in the forest types was assessed by measuring nine forest structural parameters. The occurrence of Macaranga and Mallotus species was closely related to the level of disturbance in a forest. Most Macaranga species were characteristic of high disturbance levels, while most Mallotus species preferred intermediate to low levels of disturbance. However, both genera had species at both disturbance extremes. Using multiple regression analysis, combinations of Macaranga and Mallotus species were formed and used to predict the separate forest structural parameters and the general level of disturbance of a forest. The Macaranga and Mallotus species could be grouped into (1) primary forest ‘remnant’ species; (2) generalist pioneer species; and (3) high disturbance pioneer species.     

Pulses of soil phosphorus availability in a Mexican tropical dry forest: effects of seasonality and level of wetting

Intact cores from the upper soil profile and surface litter were collected at the peak of the dry season and during the rainy period in the tropical deciduous forest of the Chamela region, Jalisco, México, to (1) analyze upper soil phosphorus (P) movement and retention, (2) compare soil P dynamic pools (soluble, bicarbonate, and microbial) in dry and rainy seasons, and (3) determine the response of these P pools to wetting. Unperturbed litter-soil cores were treated in the laboratory with either 10 mm or 30 mm of simulated rain with carrier-free ³²P and compared to a control (no water addition) to determine the fate and retention of added P. ³¹P concentrations and pools in most litter and soil fractions were higher in the dry than in the rainy season. Soluble P was 0.306 g/m² and microbial P was 0.923 g/m² in the dry season (litter plus soil) versus 0.041 (soluble) and 0.526 (microbial) g P/m² in the rainy season. After water addition, rainy-season cores retained 99.9 and 94% of ³²P in the 10- and 30-mm treatments, respectively. Dry-season samples retained 98.9 and 80% of inputs in the same treatments. Retention after wetting occurred mostly in soil (bicarbonate and microbial fractions). Simulated rainfall on rainy-season soils increased P immobilization. On the other hand, simulated rainfall on dry-season soils released P through mineralization. The P release represents between 46 and 99% of the annual litterfall return. Our results suggest that both soluble and microbial P constitute important sources for initiation of plant growth at the onset of the rainy season in tropical dry forest. Received: 23 September 1997 / Accepted: 2 February 1998     

采用统一命名的热带多型性地衣生Koordersiella属(异名:Hansfordiellopsis)的分类概要（英文）

对同一菌物不同形态型分别命名的做法于2011年结束,这就需要对非地衣化的多型性子囊菌和担子菌采用统一的命名。地衣生的Koordersiella属因此也只需要单一的名称,而后发表的Hansfordiellopsis就是该属的异名。此属共有5个种,包括在此发表的2个新组合:K.tenuissima和K.variegate combs.Nov.。本文列举了该属的地衣寄主和已报道的地理分布,同时也提供了已被接受的物种检索表。此外,在Hansfordiellopsis下发表的1个种和在Koordersiella下发表的2个种,因与该属的模式种显然为不同的属而被排除。由于缺乏分子序列数据,Koordersiella属在座囊菌纲(Dothideomycetes)中的系统学地位目前仍然不明确。     

Silicon cycled by tropical forest trees: effects of species,elevation and parent material on Mount Kinabalu,Malaysia

Plant and Soil - We aimed to compare uptake and litter flux of silicon (Si) across tropical tree species and sites on Mt. Kinabalu, Borneo. Si flux components were measured at eight plots in...     

Edge and shape effects on ant (Hymenoptera: Formicidae) species richness and composition in forest fragments

In this paper, we tested four hypotheses relative to edge and shape effects on ant communities: (i) forest edges have lower species richness than the remnant core; (ii) species richness increases with distance from the edge; (iii) irregularly shaped remnants have lower species richness than more regular remnants; (iv) there is a higher similarity of species composition between edge and core in irregular than in regular remnants. We sampled litter ant communities on the edge and core of ten remnants, in Viçosa, Minas Gerais, Brazil. Species richness was larger at the forest core than at the edges, although did not increase with distance from the edge. Species richness did not vary with shape complexity. The similarity of species composition between edge and core showed a decreasing trend with remnant area, and did not vary with shape complexity. The observed differences of species richness between forest core and edge may be due to higher harshness of edges, caused by environmental changes. The absence of relationship between species richness and distance from the edge might indicate the range of edge effects, which would be smaller than the smallest distance of core sampled. Therefore, edges would affect litter-dwelling ant species richness in a distance smaller than 50 m. The observation of species composition allowed us to notice an effect of fragmentation that would not be noticed if we were considering only species richness. Edge may serve as step to generalist species, which may use it to colonise forest remnants. Furthermore, small remnants are more colonisation-prone by such species, and have a more homogeneous species composition than large remnants.     

Checklist of American Coptotriche (Insecta: Lepidoptera: Tischeriidae) with descriptions of two new species from the tropical forest of Belize (Central America)

Two new species are described from the tropical forest of Belize: Coptotriche singularis (host-plant unknown) and C. forsteroniae (leaf-miner on Forsteronia myriantha, Apocynaceae). The external features and male genitalia are figured and described for both species. A checklist of Coptotriche species comprising 31 species currently known from the Americas is given. Most of the species are known from mainland USA and Canada, and only a few from the Neotropics (the Caribbean and Belize).     

Phenology of five tree species of a tropical dry forest in Yucatan, Mexico: effects of environmental and physiological factors

In order to relate phenological responses of trees to environmental variables we recorded the phenological patterns and select morphological and physiological traits (wood density and water potentials) of five tree species (Acacia gaumeri, Apoplanesia paniculata, Bursera simaruba, Gymnopodium floribundum, and Diospyros cuneata) in the tropical dry deciduous forest of the National Park of Dzibilchaltún, Yucatan, Mexico, over a period of 2 years (2004 and 2005). We chose two sites: one close to a permanent water source, locally known as ‘cenote’ (the CC site, ground water table was found at 2 m) and the other far from the cenote (FC site ground water table was at a depth of 10 m). Sites mainly differed in soil depth (FC site having greater soil depth) and soil nutrient characteristics (FC site more potassium, CC site more phosphorous). Our results indicated significant differences in phenology within species between sites and years, with leaf, flower and fruit production tending to be higher at the CC site and in the year 2004. Wood density and xylem water potentials were negatively related to each other, and midday water potentials were higher at the CC site. Differences in phenology found among years suggest that the timing of rainfall as well as the duration of periods without rain may play a more important role in phenology than total annual precipitation. Also differences inter-sites suggest a strong effect of site on tree phenology. Proximity to superficial bodies of water, such as cenotes, coupled with a greater concentration of available phosphorus in the soil may modify the effect of drought in this tropical dry deciduous forest.     

Spatial scale and sampling resolution affect measures of gap disturbance in a lowland tropical forest: implications for understanding forest regeneration and carbon storage

Treefall gaps play an important role in tropical forest dynamics and in determining above-ground biomass (AGB). However, our understanding of gap disturbance regimes is largely based either on surveys of forest plots that are small relative to spatial variation in gap disturbance, or on satellite imagery, which cannot accurately detect small gaps. We used high-resolution light detection and ranging data from a 1500 ha forest in Panama to: (i) determine how gap disturbance parameters are influenced by study area size, and the criteria used to define gaps; and (ii) to evaluate how accurately previous ground-based canopy height sampling can determine the size and location of gaps. We found that plot-scale disturbance parameters frequently differed significantly from those measured at the landscape-level, and that canopy height thresholds used to define gaps strongly influenced the gap-size distribution, an important metric influencing AGB. Furthermore, simulated ground surveys of canopy height frequently misrepresented the true location of gaps, which may affect conclusions about how relatively small canopy gaps affect successional processes and contribute to the maintenance of diversity. Across site comparisons need to consider how gap definition, scale and spatial resolution affect characterizations of gap disturbance, and its inferred importance for carbon storage and community composition.