The palynology of a Holocene marginal peat swamp environment in Johore,Malaysia

The development of a shallow Holocene peat near Pekan Nanas, Johore, is studied pollen-analytically. A total of 47 pollen and spore types were determined. Three main ecological phases have been observed within the pollen profile.The profile starts on fluviatile, sandy sediments and shows a succession from an open swamp vegetation with mangrove influence to a marginal peat swamp facies with river bank vegetation.A radiocarbon dating on the deepest peat sample yielded an age of 4896 years ± 70 B.P.. This age corresponds remarkedly well with a general sea-level change recorded from West Malaysian shorelines at approximately 4800 years before present.     

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.     

Effects of peat swamp logging and agricultural expansion on species richness of native mammals in Peninsular Malaysia

The biodiversity inhabiting tropical peat swamp forests in Southeast Asia is currently threatened by commercial logging and agricultural expansion. The occurrence of mammals in such forests is often poorly known and the factors influencing their occurrence in these ecosystems have rarely been quantified. We aim to determine the key habitat and landscape drivers of mammal species richness in fragmented peat swamp reserves. We conducted camera trap surveys in the North Selangor Peat Swamp Forest (NSPSF), the last remaining area of peat swamp forest on the west coast of Peninsular Malaysia. We also measured vegetation structure and landscape metrics to investigate the relationship between these factors and mammal richness. We recorded a total of 16 mammal species from 45 sampling sites using camera traps located in peat swamp forest reserves. Mammal species richness increased with the abundance of large trees and distance away from roads. Species richness decreased significantly with canopy cover and height, the abundance of fallen trees, the abundance of forest palms and saplings, distance away from rivers, and a measure of landscape compositional heterogeneity. Our findings underscore the high conservation value of logged peat swamp forests and the urgent need to halt further deforestation. We recommend: (1) protecting riparian habitat; (2) avoiding further forest conversion particularly areas supporting large trees into oil palm plantations; and (3) limiting road development within and around the NSPSF.     

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.     

Forest Structure and Support Availability Influence Orangutan Locomotion in Sumatra and Borneo

The influence of habitat structure and support availability on support use is an important aspect of understanding locomotor behavior in arboreal primates. We compared habitat structure and support availability in three orangutan study sites—two on Sumatra (Pongo abelii) in the dry‐lowland forest of Ketambe and peat swamp forest of Suaq Balimbing, and one on Borneo (Pongo pygmaeus wurmbii) in the disturbed peat swamp forest of Sabangau—to better understand orangutan habitat use. Our analysis revealed vast differences in tree and liana density between the three sites. Sabangau had a much higher overall tree density, although both Sumatran sites had a higher density of larger trees. The two peat swamp forests were more similar to each other than to Ketambe, particularly with regard to support availability. Ketambe had a wider variety of supports of different sizes and types, and a higher density of larger lianas than the two peat swamps. Orangutans in all three sites did not differ substantially in terms of their preferred supports, although Sumatran orangutans had a strong tendency to use lianas, not observed in Sabangau. Differences in observed frequencies of locomotor behavior suggest the homogeneous structure of Sabangau limits the locomotor repertoire of orangutans, with high frequencies of fewer behaviors, whereas the wider range of supports in Ketambe appears to have facilitated a more varied locomotor repertoire. There were no differences among age‐sex classes in the use of arboreal pathways in Suaq Balimbing, where orangutans selected larger trees than were typically available. This was less apparent in Sabangau, where orangutans generally used trees in relation to their environmental abundance, reflecting the homogeneous nature of disturbed peat swamp forest. These results demonstrate that forest architecture has an important influence on orangutan locomotion, which may become increasingly important as the structure of orangutan habitat continues to be altered through human disturbance. Am. J. Primatol. 74:1128‐1142, 2012. © 2012 Wiley Periodicals, Inc.     

Logged peat swamp forest supports greater macrofungal biodiversity than large‐scale oil palm plantations and smallholdings

Intensive land expansion of commercial oil palm agricultural lands results in reducing the size of peat swamp forests, particularly in Southeast Asia. The effect of this land conversion on macrofungal biodiversity is, however, understudied. We quantified macrofungal biodiversity by identifying mushroom sporocarps throughout four different habitats; logged peat swamp forest, large‐scale oil palm plantation, monoculture, and polyculture smallholdings. We recorded a total of 757 clusters of macrofungi belonging to 127 morphospecies and found that substrates for growing macrofungi were abundant in peat swamp forest; hence, morphospecies richness and macrofungal clusters were significantly greater in logged peat swamp forest than converted oil palm agriculture lands. Environmental factors that influence macrofungi in logged peat swamp forests such as air temperature, humidity, wind speed, soil pH, and soil moisture were different from those in oil palm plantations and smallholdings. We conclude that peat swamp forests are irreplaceable with respect to macrofungal biodiversity. They host much greater macrofungal biodiversity than any of the oil palm agricultural lands. It is imperative that further expansion of oil palm plantation into remaining peat swamp forests should be prohibited in palm oil producing countries. These results imply that macrofungal distribution reflects changes in microclimate between habitats and reduced macrofungal biodiversity may adversely affect decomposition in human‐modified landscapes.     

Behavior of the groundwater in a riverine-type mangrove forest

The behavior of groundwater and physical properties of bottom sediment in a riverine-type mangrove forest which is composed of a tidal creek and fringing mangrove swamps were investigated through field observations at Iriomote Island, Japan. After the tidal water ebbed from the swamp surface to the creek, groundwater levels at swamp sites near the creek fell by up to 15 cm by the next flood tide, although the fall was negligible at sites far from the creek and at the open coast outside the mangrove forest. The amount of groundwater discharged to the creek from the swamp depended strongly both on the tidal range and the presence of the steep bank which separates the tidal creek from the fringing mangrove swamp. Based on the fall of groundwater level, the bulk hydraulic conductivity of the swamp was estimated to be 1.5×10⁻² cm/s. This value is two to three orders of magnitude larger than that measured in a laboratory using small scale sediment core samples collected in the swamp. These results suggest that the presence of crowded, intricate and large animal burrows as well as sediment layers rich in mangrove humus increases permeability in the mangrove swamp. Further, it is suggested that the mangrove topography with the steep bank of the tidal creek plays an important role which enhances material exchanges through groundwater between the mangrove swamp and the adjacent offshore waters.     

Carbon fluxes from a tropical peat swamp forest floor

A tropical ombrotrophic peatland ecosystem is one of the largest terrestrial carbon stores. Flux rates of carbon dioxide (CO₂) and methane (CH₄) were studied at various peat water table depths in a mixed‐type peat swamp forest floor in Central Kalimantan, Indonesia. Temporary gas fluxes on microtopographically differing hummock and hollow peat surfaces were combined with peat water table data to produce annual cumulative flux estimates. Hummocks formed mainly from living and dead tree roots and decaying debris maintained a relatively steady CO₂ emission rate regardless of the water table position in peat. In nearly vegetation‐free hollows, CO₂ emission rates were progressively smaller as the water table rose towards the peat surface. Methane emissions from the peat surface remained small and were detected only in water‐saturated peat. By applying long‐term peat water table data, annual gas emissions from the peat swamp forest floor were estimated to be 3493±316 g CO₂ m^?2 and less than 1.36±0.57 g CH₄ m^?2. On the basis of the carbon emitted, CO₂ is clearly a more important greenhouse gas than CH₄. CO₂ emissions from peat are the highest during the dry season, when the oxic peat layer is at its thickest because of water table lowering.     

Ectomycorrhizal fungi promote growth of <Emphasis Type="Italic">Shorea balangeran</Emphasis> in degraded peat swamp forests

Shorea balangeran is an important component of peat swamp forests in Southeast Asia and is an important source of timber. However, S. balangeran has been decreasing in number due to overexploitation. The objective of this study was to investigate the effect of inoculation of native ectomycorrhizal (ECM) fungi on growth of S. balangeran in degraded peat swamp forest. Spores of Boletus sp., Scleroderma sp., and Strobilomyces sp. were collected from natural peat swamp forest in Indonesia. Seedlings of S. balangeran were inoculated with or without (control) spores and grown in sterilized peat soil under nursery conditions for 6 months. Then, the seedlings were transplanted into a degraded peat swamp forest and grown for 40 months. ECM colonization was 59–67% under nursery conditions and increased shoot height and weight. Shoot height, stem diameter, and survival rates were higher in inoculated seedlings than in control 40 months after transplantation. The results suggest that inoculation of native ECM fungi onto native tree species is useful for reforestation of degraded peat swamp forests.     

Rudabànya: Taphonomic analysis of a fossil hominid site from Hungary

The late Miocene deposits at Rudabànya, Hungary, were laid down in a shallow valley sloping westwards from a range of hills and opening out into the Pannonian Lake. Rise and fall of lake level gave rise to varying conditions, from dry land with soil formation to swamp and lake. The stratigraphic and palaeontological succession has been investigated at one of the sites, Rudabànya 2, where two cycles of deposition and erosion are represented, with soil formation, swamp conditions with lignite formation, and periods of extended high lake level succeeding each other. Both mammal and plant fossils are present at several levels. Taphonomic modifications in the Rudabànya 2 vertebrate faunas include losses of skeletal elements through carnivore selection, fluvial sorting at some levels, and post-depositional destruction by leaching and/or acid soils. The lowest level, the lower lignite, has few fossils. The fossil mammals from the level above, the grey marl, are the least modified but they are mixed with abraded, probably allochthonous, bone fragments and more complete specimens resulting from near-lake deaths. Modifications of bones by carnivores are indicated, but the specimens were too broken post-depositionally for the impact of the carnivores to be assessed. Carnivore action is also indicated for the fauna of the black clay which formed on the surface of the grey marl. The fauna consists of relatively abundant small mammals and the primates Anapithecus hernyaki and Dryopithecus hungaricus, with the latter much less common. The predator accumulating the smaller species was probably a viverrid. The red marl fauna is a transported assemblage from higher up the valley with the fossils extremely fragmentary and abraded and few identifiable specimens, almost all of which are teeth. The black mud fauna is also probably a transported assemblage, lower energy than the red marl environment, and the bones are much modified subsequently by acid corrosion similar to that seen today in bone preserved in peat bogs. Dryopithecus is a major constituent of the fauna, with Anapithecus less common. D. hungaricus is thus associated more strongly with swamp forest and shallow riverine conditions with low energy movement of water, and A. hernyaki is associated with lake shore (probably forest) conditions, accumulating in lake sediments and lake-flat sediments. The palaeoecology of the area as a whole, based on the associated flora and fauna, is a combination of swamp forest, lake shore forest and open mud flats.     

Diversity and conservation of blackwater fishes in Peninsular Malaysia,particularly in the North Selangor peat swamp forest

One of the most extreme freshwater habitats in Peninsular Malaysia is the peat swamp forest, with dark-coloured and highly acidic waters. Surprisingly, little is known about blackwater fishes in Peninsular Malaysia. Until 1968, only 26 fish species were known from blackwaters throughout Peninsular Malaysia, of which only one can be regarded as stenotopic. A recent intensive survey of part of the North Selangor peat swamp forest yielded 47 species, of which 14 are probably stenotopic taxa. These include four undescribed species and several new records for western Peninsular Malaysia. These discoveries are significant in that they include the family Chaudhuriidae which until 1985, was not reported from Sundaic Southeast Asia, and the rare genus Encheloclarias which had not been encountered for over 50 years. The rapid rate of destruction of the peat swamp forest owing to development, forestry and agricultural activities must be halted or slowed significantly to enable the proper zoological surveys and studies to be conducted. Conservation plans and environmental impact assessments based on inadequate sampling and knowledge of species present is acutely dangerous. There are no longer substantial undisturbed blackwater peat swamp forests left in most of Peninsular Malaysia. Conservation of the remaining blackwater biotopes is critically important if extinction of many species, here regarded as economically valuable renewable resources, is to be prevented.     

High-resolution palynology reveals the land use history of a Sami <Emphasis Type="Italic">renvall</Emphasis> in northern Sweden

The limited availability of historical and archaeological evidence means that much is still unknown about the development of Sami reindeer herding in Fennoscandia in both the recent and more distant past. To address this problem, high-resolution palynological analyses, ¹⁴C and ²¹⁰Pb dating were undertaken on two adjacent (<25 m apart) peat profiles collected at a recently abandoned reindeer gathering pen (renvall) near Jokkmokk (~66.6°N, 19.8°E) in the boreal forest of northern Sweden. The aim was to assess the impact of Sami reindeer herding on the local environment through a study of pollen, coprophilous fungal spores, microscopic charcoal and sedimentology. The samples collected from within an annex to the renvall indicate cycles of use and abandonment of the pen on a multi-decadal timescale between ~ad 1800–2008, most obviously in the coprophilous fungal spore archive. The pattern and timing of these cycles confirm events previously known only from oral histories. Although the local pollen assemblage zones associated with the phasing of activity were reproducible in a second peat core beyond the boundary of the renvall, the coprophilous fungal spore signal in this paired profile was much less distinctive, possibly due to the typically shorter dispersal distances for these microfossils in comparison to pollen grains.     

Contribution to the knowledge of Thai microfauna diversity: notes on rare peat swamp Rotifera, with the description of a new Lecane Nitzsch, 1872

During an ongoing study of the rotifer diversity in Thai peat swamps, several new or rare species were found. We here report on one new species, Lecane kunthuleensis n.sp., from a canal in Kun Thu Lee peat swamp, and on three rare species: Paracolurella aemula (Myers, 1934) and Lecane junkiKoste, 1975 from Kra Jood peat swamp (Suratthanee province), and Lepadella punctataWulfert, 1939 from To-Daeng peat swamp (Narathiwas province).     

Putative roles of bacteria in the carbon and nitrogen cycles in a tropical peat swamp forest

Tropical peat swamp forests are waterlogged, acidic, anoxic and oligotrophic ecosystems. They are important terrestrial carbon pools that help mitigating global warming through carbon sequestration in peat. This study aimed at investigating putative roles of bacteria in the carbon and nitrogen cycles in North Selangor peat swamp forest, Malaysia. Whole-genome sequencing was performed on four bacterial isolates using Illumina NextSeq 500 to decipher their genetic information while Gen III Microplate (Biolog) was applied to verify carbon source utilization. The isolates were identified as Dyella sp. strain C9, Dyella sp. strain C11, Klebsiella sp. strain C31 and Paraburkholderia sp. strain C35. Both Dyella spp. and Paraburkholderia sp. strain C35 were likely novel species while Klebsiella sp. strain C31 was a different strain of the type species, Klebsiella pneumoniae. Both genomic and bioassay results suggested the involvement of the isolates in the degradation of lignocellulose, carbohydrates, sugar alcohols, organic acids and aromatic compounds. The isolates could potentially perform methanotrophy, which helps to mitigate methane emissions from tropical peatlands. In addition, the isolates also contained genes encoding enzymes for nitrite, nitrate and nitric oxide reduction, as well as dissimilatory nitrate reduction to ammonium, which retains the nitrogen in the ecosystems. The results generated insights into potential functions of bacteria in the energy production and nutrient cycling of tropical peatlands, which are essential for the sustainability of high biomass and biodiversity in these ecosystems.     

Carbon dioxide emissions through oxidative peat decomposition on a burnt tropical peatland

In Southeast Asia, a huge amount of peat has accumulated under swamp forests over millennia. Fires have been widely used for land clearing after timber extraction, thus land conversion and land management with logging and drainage are strongly associated with fire activity. During recent El Niño years, tropical peatlands have been severely fire‐affected and peatland fires enlarged. To investigate the impact of peat fires on the regional and global carbon balances, it is crucial to assess not only direct carbon emissions through peat combustion but also oxidative peat decomposition after fires. However, there is little information on the carbon dynamics of tropical peat damaged by fires. Therefore, we continuously measured soil CO₂ efflux [peat respiration (RP)] through oxidative peat decomposition using six automated chambers on a burnt peat area, from which about 0.7 m of the upper peat had been lost during two fires, in Central Kalimantan, Indonesia. The RP showed a clear seasonal variation with higher values in the dry season. The RP increased logarithmically as groundwater level (GWL) lowered. Temperature sensitivity or Q₁₀ of RP decreased as GWL lowered, mainly because the vertical distribution of RP would shift downward with the expansion of an unsaturated soil zone. Although soil temperature at the burnt open area was higher than that in a near peat swamp forest, model simulation suggests that the effect of temperature rise on RP is small. Annual gap‐filled RP was 382 ± 82 (the mean ± 1 SD of six chambers) and 362 ± 74 gC m^?2 yr^?1 during 2004–2005 and during 2005–2006 years, respectively. Simulated RP showed a significant negative relationship with GWL on an annual basis, which suggests that every GWL lowering by 0.1 m causes additional RP of 89 gC m^?2 yr^?1. The RP accounted for 21–24% of ecosystem respiration on an annual basis.     

大陆东南亚(中南半岛)的主要森林植被类型介绍

大陆东南亚(中南半岛)的植被研究情况鲜为人知,至今仍无系统研究资料。该文依据数次对该地区的野外考察和资料收集,介绍了东南亚植被的研究情况和文献资料以及对该地区主要森林植被的分类和各主要植被类型的特征。大陆东南亚地区在植被分类上包括七个主要的陆生及湿地的森林植被类型:针叶林、针阔混交林、热带山地常绿阔叶林、热带雨林、热带季节性湿润林、热带季风林(季雨林)、干旱刺灌丛/萨王纳植被。其中,针叶林植被型包括温性针叶林和热性针叶林二个植被亚型;针阔混交林包括温性针阔混交林和暖温性针阔混交林二个亚型;热带雨林植被型包括热带低地常绿雨林、热带季节性雨林(热带低地半常绿雨林)、热带山地雨林及泥炭沼泽森林四个植被亚型。该文还对大陆东南亚地区植被研究历史、植被分类系统、类型特征及植物区系组成进行了讨论。     

Land use increases the recalcitrance of tropical peat

Tropical peat carbon compound composition (CCC) is a highly understudied subject. Advanced understanding of peat CCC and carbon dynamics in differing conditions is desperately needed due to large-scale utilization of these peatlands. We studied the CCC—i.e. the hemicellulosic carbohydrate and uronic acid composition and concentrations of extractives, cellulose, acid-soluble lignin and acid-insoluble lignin—in association with peat profile depth and physical structure of peat, under representative, common land uses. Samples were gathered from an undrained forest and three sites altered 20–30 years prior to the study, which in aggregate form a continuum of increasing land-use intensity (drainage-affected forest; drained and deforested degraded open site; drained and deforested site under cultivation) in Central Kalimantan, Indonesia. Peat samples were taken from depths between 10 and 115 cm that covered mostly oxic, frequently waterlogged and permanently waterlogged, anoxic conditions. Our results demonstrated greater modification of peat properties when both vegetation and hydrological conditions were altered. The differences between sites were mainly present in the topmost peat and decreased with depth. Peat located at the surface contained more labile compounds (hemicelluloses, extractives, uronic acids, cellulose) on forest sites than at the most intensively altered open sites, where peat was enriched with recalcitrant acid insoluble lignin. The effect of drainage was evident in the drained forest site, where at the approximate median water table depth peat more closely resembled open sites in terms of the peat properties. The increased recalcitrance of peat in reclaimed areas has been a result of enhanced decomposition, reduced litter input rates and, at open sites also by repeated fires.     

Leaf litter decomposition in a tropical peat swamp forest in Peninsular Malaysia

It has long been assumed that the peat underlying tropical peat swamp forests accumulates because the extreme conditions (water logged, nutrient poor, anaerobic and acidic—pH 2.9–3.5) impede microbial activity. Litterbag studies in a tropical Malaysian peat swamp (North Selangor peat swamp forest) showed that although the sclerophyllous, toxic leaves of endemic peat forest plants (Macaranga pruinosa, Campnosperma coriaceum, Pandanus atrocarpus, Stenochlaena palustris) were barely decomposed by bacteria and fungi (decay rates of only 0.0006–0.0016 k day⁻¹), leaves of M. tanarius, a secondary forest species were almost completely decomposed (decay rates of 0.0047–0.005 k day⁻¹) after 1 year. Thus it is intrinsic properties of the leaves (that are adaptations to deter herbivory in the nutrient poor environment) that impede microbial breakdown. The water of the peat swamp was very high in dissolved organic carbon (70–84 mg l⁻¹ DOC). Laboratory studies revealed initial rapid leaching of DOC from leaves (up to 1,720 mg l⁻¹ from 4 g of leaves in 7 days), but the DOC levels then fell rapidly. The leaching of DOC resulted in weight loss but the physical structure of the leaves remained intact. It is suggested that the DOC is used as a substrate for microbial growth hence lowering the concentration of DOC in the water and transferring energy from the leaves to other trophic levels. This would explain how nutrient poor tropical peatswamps support diverse, abundant flora and fauna despite low nutrient levels and lack of rapid litter cycling such as occurs in other types of tropical rainforests.     

大小兴安岭泥炭的孢粉记录及演变过程研究

根据３个高位泥炭剖面孢粉分析,揭示大注兴安岭分别于５０００ａＢ．Ｐ．、２７００ａＢ。．Ｐ．以来孢粉组合特征和植物群与气候演变过程。小兴安岭北部山地森林疲宣传早分为２个时期,５０００－３０００ａＢ．Ｐ．桦为主落叶阔叶林;３０００ａＢ．Ｐ．－－现今为红松、云冷杉为主,混有少量桦寒温必殖阔叶混交林。气候由温凉偏干向冷偏湿方向发展大兴安岭北部山地,２７００～１８００ａＢ．Ｐ．以来,已构成针叶林为主（樟子松     

Insights into the Phylogeny and Metabolic Potential of a Primary Tropical Peat Swamp Forest Microbial Community by Metagenomic Analysis

A primary tropical peat swamp forest is a unique ecosystem characterized by long-term accumulation of plant biomass under high humidity and acidic water-logged conditions, and is regarded as an important terrestrial carbon sink in the biosphere. In this study, the microbial community in the surface peat layer in Pru Toh Daeng, a primary tropical peat swamp forest, was studied for its phylogenetic diversity and metabolic potential using direct shotgun pyrosequencing of environmental DNA, together with analysis of 16S rRNA gene library and key metabolic genes. The community was dominated by aerobic microbes together with a significant number of facultative and anaerobic microbial taxa. Acidobacteria and diverse Proteobacteria (mainly Alphaproteobacteria) constituted the major phylogenetic groups, with minor representation of archaea and eukaryotic microbes. Based on comparative pyrosequencing dataset analysis, the microbial community showed high metabolic versatility of plant polysaccharide decomposition. A variety of glycosyl hydrolases targeting lignocellulosic and starch-based polysaccharides from diverse bacterial phyla were annotated, originating mostly from Proteobacteria, and Acidobacteria together with Firmicutes, Bacteroidetes, Chlamydiae/Verrucomicrobia, and Actinobacteria, suggesting the key role of these microbes in plant biomass degradation. Pyrosequencing dataset annotation and direct mcrA gene analysis indicated the presence of methanogenic archaea clustering in the order Methanomicrobiales, suggesting the potential on partial carbon flux from biomass degradation through methanogenesis. The insights on the peat swamp microbial assemblage thus provide a valuable approach for further study on biogeochemical processes in this unique ecosystem.