Impact of land conversion on environmental conditions and methane emissions from a tropical peatland.

Tropical peatlands are significant sources of methane (CH₄), but their contribution to the global CH₄ budget remains poorly quantified due to the lack of long-term, continuous and high-frequency flux measurements. To address this gap, we measured net ecosystem CH exchange (NEE-CH) using eddy covariance technique throughout the conversion of a tropical peat swamp forest to an oil palm plantation. This encompassed the periods before, during and after conversion periods from 2014 to 2020, during which substantial environmental shifts were observed.

Temporal dynamics of soil microbial C and N cycles with GHG fluxes in the transition from tropical peatland forest to oil palm plantation.

Tropical peatlands significantly influence local and global carbon and nitrogen cycles, yet they face growing pressure from anthropogenic activities. Land use changes, such as peatland forests conversion to oil palm plantations, affect the soil microbiome and greenhouse gas (GHG) emissions. However, the temporal dynamics of microbial community changes and their role as GHG indicators are not well understood.

Peatland restoration pathways to mitigate greenhouse gas emissions and retain peat carbon.

Unlabelled: Peatlands play a crucial role in the global carbon (C) cycle, making their restoration a key strategy for mitigating greenhouse gas (GHG) emissions and retaining C. This study analyses the most common restoration pathways employed in boreal and temperate peatlands, potentially applicable in tropical peat swamp forests. Our analysis focuses on the GHG emissions and C retention potential of the restoration measures.

Complete genome sequence data of an Antarctic bacterium sp. EM1 from the freshwater lake of the King George Island.

sp. EM1 is a cold-adapted bacterium isolated from the Antarctic region, which was known to exhibit mannan-degrading activity. Accordingly, this strain not only promises a cell factory for mannan-degrading enzymes, widely used in industry but also serves as a model organism to decipher its cold adaptation mechanism.

Comparison of Ganoderma boninense Isolate's Aggressiveness Using Infected Oil Palm Seedlings.

Basal stem rot incidence caused by a white-rot fungus, Ganoderma boninense, is the major disease of oil palm in Southeast Asia. The rate of disease transmission and host damage are affected by variations in pathogen aggressiveness. Several other studies have used the disease severity index (DSI) to determine G.

Dissolved NO concentrations in oil palm plantation drainage in a peat swamp of Malaysia.

Oil palm plantations in Southeast Asia are the largest supplier of palm oil products and have been rapidly expanding in the last three decades even in peat-swamp areas. Oil palm plantations on peat ecosystems have a unique water management system that lowers the water table and, thus, may yield indirect NO emissions from the peat drainage system. We conducted two seasons of spatial monitoring for the dissolved NO concentrations in the drainage and adjacent rivers of palm oil plantations on peat swamps in Sarawak, Malaysia, to evaluate the magnitude of indirect NO emissions from this ecosystem.

Soil CO and CH fluxes from different forest types in tropical peat swamp forest.

Information on temporal and spatial variations in soil greenhouse gas (GHG) fluxes from tropical peat forests is essential to predict the influence of climate change and estimate the effects of land use on global warming and the carbon (C) cycle. To obtain such basic information, soil carbon dioxide (CO) and methane (CH) fluxes, together with soil physicochemical properties and environmental variables, were measured at three major forest types in the Maludam National Park, Sarawak, Malaysia, for eight years, and their relationships were analyzed. Annual soil CO fluxes ranged from 860 to 1450 g C m yr without overall significant differences between the three forest sites, while soil CH fluxes, 1.

Evidence for high gene flow, nonrandom mating, and genetic bottlenecks of infecting oil palm ( Jacq.) plantations in Malaysia and Indonesia.

, the causal agent of basal stem rot (BSR) disease, has been recognized as a major economic threat to commercial plantings of oil palm ( Jacq.) in Southeast Asia, which supplies 86% of the world's palm oil. High genetic diversity and gene flow among regional populations of 417  isolates collected from Sabah, Sarawak, and Peninsular Malaysia (Malaysia) and Sumatra (Indonesia) were demonstrated using 16 microsatellite loci.

holobiont from a subarctic palsa bog aggravates the potential of nitrous oxide emissions.

Melting permafrost mounds in subarctic palsa mires are thawing under climate warming and have become a substantial source of NO emissions. However, mechanistic insights into the permafrost thaw-induced NO emissions in these unique habitats remain elusive. We demonstrated that NO emission potential in palsa bogs was driven by the bacterial residents of two dominant mosses especially of (SC) in the subarctic palsa bog, which responded to endogenous and exogenous factors such as secondary metabolites, nitrogen and carbon sources, temperature, and pH.

Tropical Peatland Hydrology Simulated With a Global Land Surface Model.

Tropical peatlands are among the most carbon-dense ecosystems on Earth, and their water storage dynamics strongly control these carbon stocks. The hydrological functioning of tropical peatlands differs from that of northern peatlands, which has not yet been accounted for in global land surface models (LSMs). Here, we integrated tropical peat-specific hydrology modules into a global LSM for the first time, by utilizing the peatland-specific model structure adaptation (PEATCLSM) of the NASA Catchment Land Surface Model (CLSM).

Genetic diversity and gene flow amongst admixed populations of , causal agent of basal stem rot in African oil palm ( Jacq.) in Sarawak (Malaysia), Peninsular Malaysia, and Sumatra (Indonesia).

In 1911 and 1917, the first commercial plantings of African oil palm ( Jacq.) were made in Indonesia and Malaysia in Southeast Asia. In less than 15 years, basal stem rot (BSR) was reported in Malaysia.

Substantial hysteresis in emergent temperature sensitivity of global wetland CH emissions.

Wetland methane (CH) emissions ([Formula: see text]) are important in global carbon budgets and climate change assessments. Currently, [Formula: see text] projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent [Formula: see text] temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that [Formula: see text] are often controlled by factors beyond temperature.

Linking prokaryotic community composition to carbon biogeochemical cycling across a tropical peat dome in Sarawak, Malaysia.

Tropical peat swamp forest is a global store of carbon in a water-saturated, anoxic and acidic environment. This ecosystem holds diverse prokaryotic communities that play a major role in nutrient cycling. A study was conducted in which a total of 24 peat soil samples were collected in three forest types in a tropical peat dome in Sarawak, Malaysia namely, Mixed Peat Swamp (MPS), Alan Batu (ABt), and Alan Bunga (ABg) forests to profile the soil prokaryotic communities through meta 16S amplicon analysis using Illumina Miseq.

Short- and long-term carbon emissions from oil palm plantations converted from logged tropical peat swamp forest.

Need for regional economic development and global demand for agro-industrial commodities have resulted in large-scale conversion of forested landscapes to industrial agriculture across South East Asia. However, net emissions of CO from tropical peatland conversions may be significant and remain poorly quantified, resulting in controversy around the magnitude of carbon release following conversion. Here we present long-term, whole ecosystem monitoring of carbon exchange from two oil palm plantations on converted tropical peat swamp forest.

An assessment of oil palm plantation aboveground biomass stocks on tropical peat using destructive and non-destructive methods.

The recent expansion of oil palm (OP, Elaeis guineensis) plantations into tropical forest peatlands has resulted in ecosystem carbon emissions. However, estimates of net carbon flux from biomass changes require accurate estimates of the above ground biomass (AGB) accumulation rate of OP on peat. We quantify the AGB stocks of an OP plantation on drained peat in Malaysia from 3 to 12 years after planting using destructive harvests supported by non-destructive surveys of a further 902 palms.

Microenvironmental Interplay Predominated by Beneficial Abates Fungal Pathogen Incidence in Paddy Environment.

Rice fungal pathogens, responsible for severe rice yield loss and biotoxin contamination, cause increasing concerns on environmental safety and public health. In the paddy environment, we observed that the asymptomatic rice phyllosphere microenvironment was dominated by an indigenous fungus, , which positively correlated with alleviated incidence of , one of the most aggressive plant pathogens. Through the comparative metabolic profiling for the rice phyllosphere microenvironment, two metabolites were assigned as exclusively enriched metabolic markers in the asymptomatic phyllosphere and increased remarkably in a population-dependent manner with .

Genetic Diversity and Demographic History of in Oil Palm Plantations of Sarawak, Malaysia Inferred from ITS Regions.

causes basal stem rot (BSR) and is responsible for substantial economic losses to Southeast Asia's palm oil industry. Sarawak, a major producer in Malaysia, is also affected by this disease. Emergence of BSR in oil palm planted on peat throughout Sarawak is alarming as the soil type was previously regarded as non-conducive.

The exchange of water and energy between a tropical peat forest and the atmosphere: Seasonal trends and comparison against other tropical rainforests.

Tropical rainforests control the exchange of water and energy between the land surface and the atmosphere near the equator and thus play an important role in the global climate system. Measurements of latent (LE) and sensible heat exchange (H) have not been synthesized across global tropical rainforests to date, which can help place observations from individual tropical forests in a global context. We measured LE and H for four years in a tropical peat forest ecosystem in Sarawak, Malaysian Borneo using eddy covariance, and hypothesize that the study ecosystem will exhibit less seasonal variability in turbulent fluxes than other tropical ecosystems as soil water is not expected to be limiting in a tropical forested wetland.

Image analysis procedure for the optical scanning of fine-root dynamics: errors depending on the observer and root-viewing window size.

Clarifying the dynamics of fine roots is critical to understanding carbon and nutrient cycling in forest ecosystems. An optical scanner can potentially be used in studying fine-root dynamics in forest ecosystems. The present study examined image analysis procedures suitable for an optical scanner having a large (210 mm × 297 mm) root-viewing window.

Logging disturbance shifts net primary productivity and its allocation in Bornean tropical forests.

Tropical forests play a major role in the carbon cycle of the terrestrial biosphere. Recent field studies have provided detailed descriptions of the carbon cycle of mature tropical forests, but logged or secondary forests have received much less attention. Here, we report the first measures of total net primary productivity (NPP) and its allocation along a disturbance gradient from old-growth forests to moderately and heavily logged forests in Malaysian Borneo.