As part of an ongoing effort to revise the taxonomy of air-breathing, marine, onchidiid slugs, a new genus, Laspionchis Dayrat & Goulding, gen. nov., is described from the mangroves of South-East Asia. It includes two new species, Laspionchis boucheti Dayrat & Goulding, sp. nov., and Laspionchis bourkei Dayrat & Goulding, sp. nov., both distributed from the Malacca Strait to the Philippines and Australia. This study is based on extensive field work in South-East Asia, comparative anatomy, and both mitochondrial (COI and 16S) and nuclear (ITS2 and 28S) DNA sequences. The two new species are found in the same habitat (mud surface in mangrove forests) and are externally cryptic but are distinct anatomically. Both species are also strongly supported by DNA sequences. Three cryptic, least-inclusive, reciprocally-monophyletic units within Laspionchis bourkei are regarded as subspecies: L. bourkei bourkei Dayrat & Goulding, ssp. nov., L. bourkei lateriensis Dayrat & Goulding, ssp. nov., and L. bourkei matangensis Dayrat & Goulding, ssp. nov. The present contribution shows again that species delineation is greatly enhanced by considering comparative anatomy and nuclear DNA sequences in addition to mitochondrial DNA sequences, and that thorough taxonomic revisions are the best and most efficient path to accurate biodiversity knowledge.
Saline tolerant mangrove forests partake in vital biogeochemical cycles. However, they are endangered due to deforestation as a result of urbanization. In this study, we have carried out a metagenomic snapshot of the mangrove ecosystem from five countries to assess its taxonomic, functional and antibiotic resistome structure. Chao1 alpha diversity varied significantly (P 90% relative abundance. Comparative analysis of mangrove with terrestrial and marine ecosystems revealed the strongest heterogeneity in the mangrove microbial community. We also observed that the mangrove community shared similarities to both the terrestrial and marine microbiome, forming a link between the two contrasting ecosystems. The antibiotic resistant genes (ARG) resistome was comprised of nineteen level 3 classifications dominated by multidrug resistance efflux pumps (46.7 ± 4.3%) and BlaR1 family regulatory sensor-transducer disambiguation (25.2 ± 4.8%). ARG relative abundance was significantly higher in Asian countries and in human intervention datasets at a global scale. Our study shows that the mangrove microbial community and its antibiotic resistance are affected by geography as well as human intervention and are unique to the mangrove ecosystem. Understanding changes in the mangrove microbiome and its ARG is significant for sustainable development and public health.
Fusarium genus comprises important saprophytic and phytopathogenic fungi and is widespread in nature. The present study reports the occurrence of Fusarium spp. in soils from two mangrove forests in northern Peninsular Malaysia and analyzed physico-chemical properties of the mangrove soil. Based on TEF-1α sequences, nine Fusarium species were identified: Fusarium solani species complex (FSSC) (n = 77), Fusarium verticillioides (n = 20), Fusarium incarnatum (n = 10), Fusarium proliferatum (n = 7), Fusarium lateritium (n = 4), Fusarium oxysporum (n = 3), Fusarium rigidiuscula (n = 2), Fusarium chlamydosporum (n = 1), and Fusarium camptoceras (n = 1); FSSC isolates were the most prevalent. Phylogenetic analysis of the combined TEF-1α and ITS sequences revealed diverse phylogenetic affinities among the FSSC isolates and potentially new phylogenetic clades of FSSC. Soil analysis showed varied carbon content, pH, soil moisture, and salinity, but not nitrogen content, between sampling locations. Regardless of the physico-chemical properties, various Fusarium species were recovered from the mangrove soils. These were likely saprophytes; however, some were well-known plant pathogens and opportunistic human pathogens. Thus, mangrove soils might serve as inoculum sources for plant and human pathogenic Fusarium species. The present study demonstrates the occurrence of various Fusarium species in the extreme environment of mangrove soil, thereby contributing to the knowledge on species diversity in Fusarium.
Tropical peat swamp forest (PSF) is a unique wetland ecosystem with distinct vegetation types. Due to the waterlogged environment, the stand characteristics in this ecosystem are different from those of other inland forests. This paper highlights stand characteristics of a PSF based on our investigation of a 1 ha ecological plot established in a Virgin Jungle Reserve (VJR) at Compartment 100, Pekan Forest Reserve, Pahang, Malaysia. This site is considered a Gonystylus bancanus-rich area. From the inventory, we recorded a total of 49 tree species from 38 genera and 25 families among all trees of ≥ 10 cm in diameter at breast height. Calophyllum ferrugineum var. ferrugineum was the most abundant species, followed by G. bancanus. The forest appeared healthy, as all tree characteristics (crown shape, log grade and climber infestation) generally fell within Classes 1 and 2 (good and moderate categories), with the exception of crown illumination which majority of the trees were rated as class 3 (received less sunlight). The latter finding indicates that most of the trees living under the canopy received minimal illumination. In terms of total tree biomass, we estimated that about 414.6 tonnes exist in this 1 ha area; this tree biomass is higher than in some PSF areas of Sumatra, Indonesia.
The status and distribution of Mimosa pigra L., a semi-aquatic invasive species in Peninsular Malaysia, were continuously assessed between 2004 and 2007. This assessment investigated its population stand density and related weed management activities. In total, 106 sites of 6 main habitat types i.e., construction site (CS), dam/ reservoir (DM), forest reserve (FR), plantation (PL), river bank/waterway (RB) and roadside (RD) were assessed, and 55 sites were recorded with M. pigra populations. A CS is the most likely habitat to be infested with M. pigra (16 out of 18 assessed sites have this weed), whereas none of the FR visited were found to harbour M. pigra. In terms of population stand density, 41 populations were in the low range of stand density (individual plant of ≤5 m(-2)), compared to only 9 populations in the high range of stand density (individual plant of >10 m(-2)). In general, the current impact of M. pigra infestation on natural habitats is relatively low, as its distribution is only confined to disturbed areas. However, continuous monitoring of this weed species is highly recommended, especially in the riparian zone and wetland habitats.
Vapour pressure deficit (VPD) analysis introduces an approach to develop a better basis for the control of the environment of lowland greenhouses in Malaysia. The study of vapour pressure deficit (VPD) is to show air moisture conditions for plant production while taking into account different temperature levels. The purpose of this project is to develop a real-time automatic temperature and relative humidity control system in the lowland tropical greenhouse using a PIC16f876A microcontroller. The controller will then be used to monitor the temperature, relative humidity and VPD in the planting of Chili Kulai (Titisan 15). The fertigation system was introduced to the greenhouse to fertilize and irrigate the plant as well as to provide moisture to the environment. A swamp cooler was used to bring down the temperature and increase moisture content in the greenhouse. Ventilators were installed to remove the heat in the greenhouse. The study was carried out in an experimental greenhouse located at the Institute of Advanced Technology, Universiti Putra Malaysia (UPM).
Mineral elemental uptake by Colocasia esculenta growing in swamp agroecosystem was studied following 14, 18 or 28 months of field spraying (MAT, months after treatment) with herbicide Gramoxone ® (paraquat). In overall, Al (68226.67 + 24066.56 μg/g dw) was the major element in riverine alluvial swamp soil, followed by micronutrient Fe (22280.00 + 6328.87 μg/g dw).
Concentration of macronutrient K (20733.33 + 7371.82 μg/g dw) was the highest in swamp taro leaf followed by macronutrient Ca (7050.00 + 3767.26 μg/g dw). In overall, the order of importance of the average mineral concentration in swamp taro leaf was K > Ca > Mn > Al > Na > Fe > Zn > Br > Co. However at 14 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Al > Na > Mn > Fe > Zn > Br > Co. At 18 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Al > Fe > Na > Zn > Br > Co. At 28 MAT, the order of importance of mineral content concentration in swamp taro leaf was K > Ca > Mn > Fe > Al > Zn > Na > Br > Co. In overall, the average order of importance of mineral elemental uptake or the soil plant transfer coefficient was Mn > K > Na > Zn > Co > Fe > Al; similar with the order at 28 MAT. However, at 14 MAT the order of importance of the soil plant transfer coefficient was different at Mn > K > Na > Co > Zn > Al > Fe.
Coeliccia matok sp. nov. (holotype male from Borneo, Sarawak, Samarahan Division, peat swamp forest at old UNIMAS campus, 25 ii 2008, to be deposited in BMNH) and Coeliccia paludensis sp. nov. (holotype male from Borneo, Kalimantan Tengah, peat swamp forest in ex Mega Rice Project Block E, 18 vi 2012, in RMNH) are described from Borneo. The two new species are apparently confined to peat swamp forest (C. paludensis) or largely confined to peat swamp forest and related forest formations (C. matok). Coeliccia macrostigma Laidlaw is redescribed and all available information on it is summarised. Additional terminology for characters of the prothorax in Coeliccia species is introduced. Distribution maps are given for all three species considered.
Podolestes parvus sp. nov. is described and illustrated from both sexes from Sarawak, Malaysian Borneo (holotype male Maludam National Park, Betong Division, Sarawak, 10 vii 2012, deposited in RMNH). The new species is closest to P. atomarius Lieftinck, 1950 and is the smallest species yet known in its genus. A full set illustrations of P. atomarius is provided for comparison. [Species Zoobank URL: urn:lsid:zoobank.org:act:EE7ABAB0-8683-4D25-8A2C-76977931FD87].
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. LE and H show little variability across seasons in the study ecosystem, with LE values on the order of 11 MJ m-2 day and H on the order of 3 MJ m-2 day-1. Annual evapotranspiration (ET) did not differ among years and averaged 1579 ± 47 mm year-1. LE exceeded characteristic values from other tropical rainforest ecosystems in the FLUXNET2015 database with the exception of GF-Guy near coastal French Guyana, which averaged 8-11 MJ m-2 day-1. The Bowen ratio (Bo) in tropical rainforests in the FLUXNET2015 database either exhibited little seasonal trend, one seasonal peak, or two peaks. Volumetric water content (VWC) and VPD explained a trivial amount of the variability of LE and Bo in some of the tropical rainforests including the study ecosystem, but were strong controls in others, suggesting differences in stomatal regulation and/or the partitioning between evaporation and transpiration. Results demonstrate important differences in the seasonal patterns in water and energy exchange across different tropical rainforest ecosystems that need to be understood to quantify how ongoing changes in tropical rainforest extent will impact the global climate system.
This study aimed to document the fish diversity and water quality at Semariang mangrove area, Kuching, Sarawak, which is located at the eastern part of Kuching Wetland National Park. Field samplings were carried out in 2009 during the construction of the flood mitigation channel at the eastern part of the park. A total of 21 families represented by 37 species of fish were caught from the area. The six dominant families in terms of the number of individuals caught were Mugilidae (16%), Leiognathidae (16%), Ambassidae (11%), Ariidae (9%), Lutjanidae (8%) and Plotosidae (6%). In terms of the percentage of six dominant genera based on the number of individuals caught, 16% was represented by Valamugil, 11% by Ambassis, 10% by Gazza, 9% by Arius, 8% by Lutjanus and 6% by Plotosus. The values of diversity and richness indices were lower at stations located close to the flood mitigation channel. Similarly, the concentrations of dissolved oxygen were lower and total suspended solids were significantly higher at stations close to the channel and sand mining area. Therefore, fish fauna and water quality at Semariang mangrove area were affected during the construction of the flood mitigation channel.
This paper focuses on Langat River basin which is experiencing fast pace land use changes and accelerated soil erosion associated with land clearing and earthwork activities. Land use changes detected from Landsat imageries from 1989-1999 show that urban expansion is the most active, i.e. recording an expansion of 180% over that time period. The major land use reduction is the tropical dipterocarp rainforest located along the upper catchment of the Langat River and the mangrove forest found along Kuala Langat in the west. The 11% decline in the trend of the forest over that decade is anticipated to contribute in the near future. Results from logistic regression on the casual factors of rapid land use changes are attributed to three significant variables namely transport accessibility, population dynamics and agriculture. The eroded material due to land use changes enters into the Langat River systems as suspended sediments and contributed as non point source of pollution. Some finer sediment is being discharged offshore forming sediment plumes at the river estuary. Sediment plumes detected by Landsat TM imageries were analysed. It is found that the dispersion was not extensive and generally the suspended solids existed at low concentration (varying from 10-50 mg/l). This result is unexpected considering the rapid land use and land cover change that is occurring within the basins. These are mainly due to the loss of sediments during flooding into flood plain and active dredging of the river channels.
Dipterocarpaceae is the dominant tree family in the tropical rain forests of Southeast Asia. Borneo is the centre of diversity for the dipterocarps. Identification of hotspots is important for forest and biodiversity conservation efforts. Species Occurrence Models (SOMs) were generated for all 247 species of dipterocarps recorded in Sarawak using herbarium occurrence data and based on the best model selected. The species occurrence density map for each genus and category (endemic and non endemic) was generated by overlaying the SOMs of all species in each genus or category. The species occurrence density maps were analyzed with land cover map from Landsat 7-EMT+ images and protected forest areas for identifying hotspots for conservation in Sarawak. Overlaying the SOM maps revealed that areas in central Sarawak and the southwest region (northwest Borneo around Kuching) are the main hotspots of dipterocarp diversity in Sarawak while the coastal lowland areas in the lower Rejang and Baram River which are mainly peat swamp forest are poorer in species occurrence density. In terms of endemism, as with dipterocarp diversity, the mixed diptercarp forest of central Sarawak is also the most important hotspot. Gap analysis revealed that most protected forest areas are in southwest Sarawak (Bako, Kubah, Tanjung Datu and Gunung Gading National Parks) and in the northern part of Sarawak (Niah, Lambir Hills and Mt Mulu National Parks). This leaves the hotspot in the central part of Sarawak least protected. Protected areas only cover between 2 and 4% of the total areas for the different hotspots (75% species density) while majority of the hotspots that are still forested are outside the protected areas.
This paper reports on a new record of the itch moth from the family Lymantriidae, Toxoproctis hemibathes (Swinhoe), for Peninsular Malaysia. The islands of Sumatera and Borneo are known to be within the geographical range of Lymantriidae, their habitat preference being the wetland and coastal forests. Our study showed that this species can also erupt in large numbers in specific locations in the southern parts of Peninsular Malaysia and thus, our finding is considered a new record for T. hemibathes (Swinhoe). This specimens were collected using portable ultra violet (UV) light trap during a population outbreak of this species in the Labis District of Johore.
Previous studies have found positive correlations between mangrove forest extent and fisheries yield but none of these univariate relationships provide a reliable estimate of yield from mangrove area. This study tests the hypothesis that the nursery ground value or natural production of fish and shrimps is related to the hydrogeomorphology settings of mangrove forests by using multivariate redundancy analysis (RDA). The hydrogeomorphological metrics of five mangrove forests imaged by satellite were measured using Geographical Information System (GIS). The RDA indicated that the metrics, including mangrove area, multiple waterways and creeks, mangrove-river interface, waterway surface area and sediment organic matter, influenced the diversity and abundance of fish and shrimps. Larger values of these metrics increase the abundance of economically important fish species of the families Lutjanidae, Haemulidae, Serranidae and economically-important penaeid shrimps. Sediment organic matter also significantly correlates with the distribution and abundance of fish that feed off the bottom such as the Leiognathidae, Clupeidae and Mullidae. Mangrove forests with combinations of large mangrove area, river surface area, high stream ordering and longest mangrove-river interface will provide greater role as nursery grounds for fish and shrimps.
Dye is one of the pollutants found in water bodies because of the increased growth of the textile industry. In this study, Scirpus grossus was planted inside a constructed wetland to treat mixed dye (methylene blue and methyl orange)-containing wastewater under batch and continuous modes. The plants were exposed to various concentrations (0, 50, 75, and 100 mg/L) of mixed dye for 72 days (with hydraulic retention time of 7 days for the continuous system). Biological oxygen demand, chemical oxygen demand, total organic carbon, pH, temperature, ionic content, and plant growth parameters were measured. Results showed that S. grossus can withstand all the tested dye concentrations until the end of the treatment period. Color removal efficiencies of 86, 84, and 75% were obtained in batch mode, whereas 90%, 85%, and 79% were obtained in continuous mode for 50, 75, and 100 mg/L dye concentrations, respectively. Fourier-transform infrared analysis confirmed the transformation of dye compounds after treatment and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy analysis showed that most of the intermediate compounds were not absorbed into plants but adsorbed onto the surface of the root structure.
The sika deer (Cervus nippon yesoensis) population in the Ramsar-listed Kushiro Wetland has increased in recent years, and the Ministry of the Environment of Japan has decided to take measures to reduce the impact of deer on the ecosystem. However, seasonal movement patterns of the deer (i.e., when and where the deer inhabit the wetland) remain unclear. We examined the seasonal movement patterns of sika deer in the Kushiro Wetland from 2013 to 2015 by analyzing GPS location data for 28 hinds captured at three sites in the wetland. Seasonal movement patterns were quantitatively classified as seasonal migration, mixed, dispersal, nomadic, resident, or atypical, and the degree of wetland utilization for each individual was estimated. The area of overlap for each individual among intra-capture sites and inter-capture sites was calculated for the entire year and for each season. Our results showed that the movement patterns of these deer were classified not only as resident but also as seasonal migration, dispersal, and atypical. Approximately one-third of the individuals moved into and out of the wetland during the year as either seasonal migrants or individuals with atypical movement. Some of the individuals migrated to farmland areas outside the wetland (the farthest being 69.9 km away). Half of the individuals inhabited the wetland all or most of the year, i.e., 81-100% of their annual home range was within the wetland area. Even among individuals captured at the same site, different seasonal movement patterns were identified. The overlap areas of the home ranges of individuals from the same capture sites were larger than those for individuals from different capture sites (e.g., mean of annual home range overlap with intra-capture sites: 47.7% vs. inter-sites: 1.3%). To achieve more effective ecosystem management including deer management in the wetland, management plans should cover inside and outside of the wetland and separate the population into multiple management units to address the different movement patterns and wetland utilization of the population.
Brunei Bay, which receives freshwater discharge from four major rivers, namely Limbang, Sundar, Weston and Menumbok, hosts a luxuriant mangrove cover in East Malaysia. However, this relatively undisturbed mangrove forest has been less scientifically explored, especially in terms of vegetation structure, ecosystem services and functioning, and land-use/cover changes. In the present study, mangrove areal extent together with species composition and distribution at the four notified estuaries was evaluated through remote sensing (Advanced Land Observation Satellite-ALOS) and ground-truth (Point-Centred Quarter Method-PCQM) observations. As of 2010, the total mangrove cover was found to be ca. 35,183.74 ha, of which Weston and Menumbok occupied more than two-folds (58%), followed by Sundar (27%) and Limbang (15%). The medium resolution ALOS data were efficient for mapping dominant mangrove species such asNypa fruticans,Rhizophora apiculata,Sonneratia caseolaris,S. albaandXylocarpus granatumin the vicinity (accuracy: 80%). The PCQM estimates found a higher basal area at Limbang and Menumbok-suggestive of more mature vegetation, compared to Sundar and Weston. Mangrove stand structural complexity (derived from the complexity index) was also high in the order of Limbang > Menumbok > Sundar > Weston and supporting the perspective of less/undisturbed vegetation at two former locations. Both remote sensing and ground-truth observations have complementarily represented the distribution ofSonneratiaspp. as pioneer vegetation at shallow river mouths,N. fruticansin the areas of strong freshwater discharge,R. apiculatain the areas of strong neritic incursion andX. granatumat interior/elevated grounds. The results from this study would be able to serve as strong baseline data for future mangrove investigations at Brunei Bay, including for monitoring and management purposes locally at present.
The treatment of single and binary azo dyes, as well as the effect of the circuit connection, aeration, and plant on the performance of UFCW-MFC, were explored in this study. The decolorization efficiency of Remazol Yellow FG (RY) (single dye: 98.2 %; binary dye: 92.3 %) was higher than Reactive Black 5 (RB5) (single: 92.3 %; binary: 86.7 %), which could be due to monoazo dye (RY) requiring fewer electrons to break the azo bond compared to the diazo dye (RB5). In contrast, the higher decolorization rate of RB5 in binary dye indicated the removal rate was affected by the electron-withdrawing groups in the dye structure. The closed circuit enhanced about 2% of color and 4% of COD removal. Aeration improved the COD removal by 6%, which could be contributed by the mineralization of intermediates. The toxicity of azo dyes was reduced by 11-26% and the degradation pathways were proposed. The dye removal by the plants was increased with a higher contact time. RB5 was more favorable to be uptook by the plant as RB5 holds a higher partial positive charge. 127.39 (RY), 125.82 (RB5), and 58.66 mW/m3 (binary) of maximum power density were generated. The lower power production in treating the binary dye could be due to more electrons being utilized for the degradation of higher dye concentration. Overall, the UFCW-MFC operated in a closed circuit, aerated, and planted conditions achieved the optimum performance in treating binary azo dyes containing wastewater (dye: 87-92%; COD: 91%) compared to the other conditions (dye: 83-92%; COD: 78-87%).
Tropical peatlands are important carbon stores that are vulnerable to drainage and conversion to agriculture. Protection and restoration of peatlands are increasingly recognised as key nature based solutions that can be implemented as part of climate change mitigation. Identification of peatland areas that are important for protection and restauration with regards to the state of their carbon stocks, are therefore vital for policy makers. In this paper we combined organic geochemical analysis by Rock-Eval (6) pyrolysis of peat collected from sites with different land management history and optical remote sensing products to assess if remotely sensed data could be used to predict peat conditions and carbon storage. The study used the North Selangor Peat Swamp forest, Malaysia, as the model system. Across the sampling sites the carbon stocks in the below ground peat was ca 12 times higher than the forest (median carbon stock held in ground vegetation 114.70 Mg ha-1 and peat soil 1401.51 Mg ha-1). Peat core sub-samples and litter collected from Fire Affected, Disturbed Forest, and Managed Recovery locations (i.e. disturbed sites) had different decomposition profiles than Central Forest sites. The Rock-Eval pyrolysis of the upper peat profiles showed that surface peat layers at Fire Affected, Disturbed Forest, and Managed Recovery locations had lower immature organic matter index (I-index) values (average I-index range in upper section 0.15 to -0.06) and higher refractory organic matter index (R -index) (average R-index range in upper section 0.51 to 0.65) compared to Central Forest sites indicating enhanced decomposition of the surface peat. In the top 50 cm section of the peat profile, carbon stocks were negatively related to the normalised burns ratio (NBR) (a satellite derived parameter) (Spearman's rho = -0.664, S = 366, p-value = <0.05) while there was a positive relationship between the hydrogen index and the normalised burns ratio profile (Spearman's rho = 0.7, S = 66, p-value = <0.05) suggesting that this remotely sensed product is able to detect degradation of peat in the upper peat profile. We conclude that the NBR can be used to identify degraded peatland areas and to support identification of areas for conversation and restoration.