Displaying publications 81 - 100 of 389 in total

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  1. Mahirah Jahari, Khairunniza-Bejo, S., Abdul Rashid Mohamed Shariff, Helmi Zulhaidi Mohd. Shafri
    MyJurnal
    In this research wok, three different techniques of change detection were used to detect changes in forest areas. One of the techniques used a local similarity measure approach to detect changes. This new approach of change detection technique, which used mutual information to measure the similarity between two multi-temporal images, was developed based on correspondence of the pixel values, rather than the difference in their intensity. Pixels suffering any changes will be maximally dissimilar. The study was conducted using multi-temporal SPOT 5 satellite images, with the resolution of 10 m x10 m on 5th August 2005 and 13th June 2007. The experimental results show that local mutual information provides more reliable results in detecting changes of the multitemporal images containing different lighting condition compared to the image differencing and NDVI technique, specifically in areas with less plant growth. In addition, it can also overcome the problem on selecting the threshold value. Besides, the findings of this study have also shown that band 3, which is sensitive to vegetation biomass, gave the best result in detecting area of changes compared to the others.
    Matched MeSH terms: Forests
  2. Nawawi, S.W., S. Sabikan
    MyJurnal
    In recent years, there has been an increasing interest in quadcopter technology
    implementation in the real world; for instance in real estate photography, aerial surveying, periodic
    forest monitoring, and search/rescue missions. Generally, each quadcopter implementation required
    different sensors which are needed to attach and integrate into quadcopter system. However, the most
    critical part in almost cases is preparing the quadcopter flight performance and capability to be suited
    in any outdoor applications. Because of that reason, this paper has proposed an implementation of
    Open-Source Project (OSPs) platform as autonomous Unmanned Aerial Vehicle (UAV) quadcopter
    development that can be fitted for any outdoor applications or even in research experimental purposes.
    We started out with an explanation about the general approach that has been used in the development
    of a quadcopter testbed, and then followed with detail explanations in the OSP platform approach.
    The OSP platform is the most popular approach. The main reason is because of their flexibility in both
    hardware and software. The basic quadcopter configuration for autonomous flight also presented and
    applied. This paper also provided several outdoor experiments results in uncontrolled environment
    that have been executed using our developed testbed to evaluate their performance, such as attitude
    and altitude stabilization, interference and vibration effect, and trajectory mapping generation.
    Finally, throughout this project, we realized that the OPSs quadcopter platform has offered almost
    complete frameworks in the development of quadcopter for any outdoor applications or even as a
    research testbed system.
    Matched MeSH terms: Forests
  3. Too CC, Ong KS, Ankenbrand MJ, Lee SM, Yule CM, Keller A
    Genome Announc, 2018 Jun 21;6(25).
    PMID: 29930066 DOI: 10.1128/genomeA.00561-18
    We report the draft genome sequence of a bacterial isolate, Paraburkholderia sp. strain C35, which was isolated from a Malaysian tropical peat swamp forest. The putative genes for the biogeochemical processes were annotated and are publicly available in the online databases.
    Matched MeSH terms: Forests
  4. Too CC, Ong KS, Ankenbrand MJ, Lee SM, Yule CM, Keller A
    Genome Announc, 2018 Jun 21;6(25).
    PMID: 29930065 DOI: 10.1128/genomeA.00560-18
    We report here the draft genome of Klebsiella sp. strain C31, a bacterial isolate from the North Selangor peat swamp forest in Malaysia. The putative genes for the biogeochemical processes of the genome were annotated and investigated.
    Matched MeSH terms: Forests
  5. Too CC, Ong KS, Lee SM, Yule CM, Keller A
    Genome Announc, 2018 Jun 21;6(25).
    PMID: 29930031 DOI: 10.1128/genomeA.00459-18
    We report here the draft genome sequences of a bacterial isolate, Dyella sp. strain C11, which was isolated from a Malaysian tropical peat swamp forest. The putative genes for the biogeochemical processes were annotated, and the genome was deposited in an online database.
    Matched MeSH terms: Forests
  6. T Ismail TNS, A Kassim NF, A Rahman A, Yahya K, Webb CE
    Trop Med Infect Dis, 2018 Jul 23;3(3).
    PMID: 30274473 DOI: 10.3390/tropicalmed3030077
    Due to conservation and rehabilitation efforts, mangrove forests represent some of the largest environmental niches in Malaysia. However, there is little information on the potential risks posed by mosquitoes that are directly and indirectly associated with mangrove forests. To study the potential health risk to humans active within and in close vicinity of mangrove forests, this research focused on the day biting habits of mosquitoes in mangrove forests of Kedah, Malaysia. The bare leg catch (BLC) method was used to collect adult mosquitoes during a 12-h period from 7:30 a.m. to 7:30 p.m. in both disturbed and less disturbed areas of mangroves. In total, 795 adult mosquitoes from 5 genera and 8 species were collected, and over 65% of the total mosquitoes were collected from the less disturbed area. The predominant species from the less disturbed area was Verrallina butleri; in the disturbed area the dominant species was Culex sitiens. The peak biting hour differed for each species, with Aedes albopictus and Cx. sitiens recorded as having a bimodal biting activity peak during dawn and dusk. For Ve. butleri an erratic pattern of biting activity was recorded in the less disturbed area but it peaked during the early daytime for both collection points. Overall, the distinct pattern of day biting habits of mosquitoes within mangroves peaked during dawn and dusk for the less disturbed area but was irregular for the disturbed area throughout the day. The presence of vectors of pathogens such as Ae. albopictus for both areas raises the need for authorities to consider management of mosquitoes in mangrove forests.
    Matched MeSH terms: Forests
  7. Suhailah A, Che Salmah M
    Sains Malaysiana, 2014;43:667-674.
    Seasonal changes in Ephemeroptera, Plecoptera and Trichoptera (EPT) community was studied at rivers in Gunung Jerai Forest Reserve, Kedah, Malaysia. The rivers were visited monthly from September 2007 to August 2008 to sample aquatic insects using D-pond nets. More EPT were found in the wet season (10664 individuals) compared with the dry season (6599 individuals). In all rivers, ephemeropteran populations was highest during the wet season (z=-2.465, p=0.014). Meanwhile, the plecopteran population was low and almost constant throughout seasons in all rivers (z=-2.280, p=0.023). Trichopterans exhibited the highest peak of abundance in the dry season (z=-6.096, p=0.00). Concomitantly, higher diversity was recorded in the dry season (29 taxa) compared with 25 taxa recorded in wet season from all rivers. Tupah River had the most diverse EPT assemblage during the dry season. In wet season, the abundance of ephemeropterans genera such as Baetis, Platybaetis, Campsoneuria and Thalerosphyrus increased tremendously especially in Teroi River.
    Matched MeSH terms: Forests
  8. Phua MH, Wong W, Goh MH, Kamlisa Uni Kamlun, Julius Kodoh, Teo S, et al.
    Sains Malaysiana, 2014;43:1461-1470.
    Reducing emissions from deforestation and forest degradation-plus (REDD+) is considered as an important mitigation strategy against global warming. However, the implementation of REDD+ can adversely affect local people who have been practicing shifting cultivation for generations. We analyzed Landsat-5 Thematic Mapper images of 1990 and 2009 to quantifying deforestation and forest degradation at Lubuk Antu District, a typical rural area of Sarawak, Malaysia. The results showed significant loss of intact forest at 0.9% per year, which was substantially higher than the rate of Sarawak. There were increases of oil palm and rubber areas but degraded forest, the second largest land cover type, had increased considerably. The local people were mostly shifting cultivators, who indicated readiness of accepting the REDD+ mechanism if they were given compensation. We estimated the monthly willingness to accept (WTA) at RM462, which can be considered as the opportunity cost of foregoing their existing shifting cultivation. The monthly WTA was well correlated with their monthly household expenses. Instead of cash payment, rubber cultivation scheme was the most preferred form of compensation.
    Matched MeSH terms: Forests
  9. Salmiati, Nor Zaiha A., Mohd Ismid M.S.
    Sains Malaysiana, 2015;44:1223-1228.
    Temporal changes of Ephemeroptera, Plecoptera and Trichoptera (EPT) communities were investigated at the study area of Gunung Pulai Recreational Forest, Johor, Malaysia. Taxa diversity were also studied to determine the seasonality impact on certain benthic communities. Sampling of aquatic insects were carried out from November 2012 to July 2013 using rectangular dip net. As a result, more EPT were found during the dry season (1533 individuals) compared to wet season (321 individuals). Concomitantly, higher diversity was also recorded in the dry season. Among these three investigated orders, Trichoptera represented the most diverse community with three families recorded, followed by Plecoptera (2 families) and Ephemeroptera (1 family). Caddisfly family Hydropsychidae were found to be abundant in the study area. Therefore, seasonality impact on EPT assemblage at Gunung Pulai Recreational Forest is extremely evident.
    Matched MeSH terms: Forests
  10. Wang YJ, Shi XP, Peng Y, Tao JP, Zhong ZC
    Sains Malaysiana, 2012;41:649-657.
    Dwarf bamboo is recognized as a significant determinant of the structure and dynamics in temperate forests. Quantitative relationships between the abundance (density and coverage) of dwarf bamboo, Fargesia nitida, and micro-environments, species diversity on the floor were estimated in an Abies faxoniana pure forest in southwest China. Understory microenvironmental conditions (daily differences temperature and moisture, RPPFD under bamboo layer and ground cover) changed dramatically with the bamboo density. Stepwise multiple regression analyses indicated that abundance of F. nitida was mainly correlated with canopy characteristics and disturbance factors in the A. faxoniana pure forest. All richness indices decreased significantly with the bamboo density and RPPFD under bamboo layer. Importance values (IV) of understory species in different bamboo densities and Detrended canonical correspondence analysis (DCCA) indicated three understory plant groups, resistant to high bamboo abundance (Group A), resistant to intermediate bamboo abundance (Group B) and sensitive to bamboo abundance (Group C). These groups mainly responded to abundance of bamboo and RPPFD under bamboo layer, resulted from the integration of characteristics of bamboo, canopy and topography factors. Different bamboo abundance had different influences on understory species diversity and groups. Dense F. nitida condition (> 10 culms/m2) had significant negative effect and 0-5 bamboo condition had not significant negative effect on understory species diversity in A. faxoniana forest. We suggest the fine-scale analysis on effects of bamboo abundance should be taken account into considering in heterogeneous patches in process of the succession and regeneration of natural forests.
    Matched MeSH terms: Forests
  11. Ahmet Tolunay, Ayhan Akyol
    Sains Malaysiana, 2015;44:159-166.
    Sustainable forest management (SFM) practices have started in 1999 in Turkey. A set of criteria and indicators, composed by the General Directorate of Forestry (GDF) on the basis of the criteria and indicators defined in the Pan-European and Near Eastern Processes, was enquired via a survey to serve this purpose. GDF tested the sustainability under the following titles: Situation of forest resources, biodiversity, health and vitality, production capacity and functions, protective functions and environmental and socio-economic functions. There were problems in identification and definition of SFM criteria and indicators. Biological diversity indicators has been selected, described and developed in this study. At this phase, the survey was completed upon receiving the views of the scientists interested in different dimensions of this topic as well as the views of other interest groups affiliated with forestry. As a result, there were 13 indicators that may be used as the basis of a regional or forest management unit level for the purpose of protecting, developing and maintaining biodiversity. Furthermore, these indicators are instruments, which may easily be used by relevant decision-makers in the management of forest resources in a more effective and productive manner.
    Matched MeSH terms: Forests
  12. Yee SA, Phooi KC, Chong LP
    Sains Malaysiana, 2018;47:1439-1445.
    Vocalisations of tropical birds are still largely unexplored particularly the nocturnal species. This study examined and
    quantitatively described the territorial calls and duets of the Sunda Scops-Owl (Otus lempiji), Brown Boobook (Ninox
    scutulata) and Spotted Wood-Owl (Strix seloputo) based on 105 territorial call and four duetting recordings collected
    from one forest reserve and oil palm smallholdings in Selangor, Peninsular Malaysia. Wilcoxon signed-rank tests found
    significant differences (p<0.05) for almost all vocal parameters measured from the spectrograms derived from the duets
    with one higher-pitched than the other. Being the first study to describe the vocal structure of the duetting calls of the
    three Malaysian strigids, this study serves as a baseline for future behavioural study of nocturnal birds particularly
    pertaining to conspecific interactions in the Sunda region.
    Matched MeSH terms: Forests
  13. Yap ML, Chew LJ, Pritpal Singh SS, Sekawi Z, Chee HY, Ong HKO, et al.
    Trop Biomed, 2021 Jun 01;38(2):122-128.
    PMID: 34172700 DOI: 10.47665/tb.38.2.047
    Leptospirosis is an emerging zoonotic disease endemic in tropical regions. Aiming at assessing the potential infection risks via recreational exposure, the molecular prevalence of pathogenic Leptospira in 14 amenity forests in five selected districts of the state of Perak was determined. Water and soil samples along streams and waterfalls were subjected to culture of leptospires and the pathogenic Leptospira spp. was detected by lipL32-based polymerase chain reaction (PCR). Twenty out of 154 samples (13%) that tested positive for leptospires were mostly soils and still water recorded with tolerable temperatures (22.2- 26.5°C) and pHs (5.73-6.70). The localised prevalence was highly varied among eight positive forests (6.7-41.7%), particularly higher in Kampar and Kinta districts which are the more populated urban areas. The importance of public health surveillance should not be underrated given the high prevalence of Leptospira spp. in forests in close proximity to indigenous settlements, even where the places are clean. Overall, this study discovered a wide distribution of pathogenic Leptospira spp. in recreational areas.
    Matched MeSH terms: Forests
  14. Heděnec P, Jiménez JJ, Moradi J, Domene X, Hackenberger D, Barot S, et al.
    Sci Rep, 2022 Oct 17;12(1):17362.
    PMID: 36253487 DOI: 10.1038/s41598-022-21563-z
    Soil invertebrates (i.e., soil fauna) are important drivers of many key processes in soils including soil aggregate formation, water retention, and soil organic matter transformation. Many soil fauna groups directly or indirectly participate in litter consumption. However, the quantity of litter consumed by major faunal groups across biomes remains unknown. To estimate this quantity, we reviewed > 1000 observations from 70 studies that determined the biomass of soil fauna across various biomes and 200 observations from 44 studies on litter consumption by soil fauna. To compare litter consumption with annual litterfall, we analyzed 692 observations from 24 litterfall studies and 183 observations from 28 litter stock studies. The biomass of faunal groups was highest in temperate grasslands and then decreased in the following order: boreal forest > temperate forest > tropical grassland > tundra > tropical forest > Mediterranean ecosystems > desert and semidesert. Tropical grasslands, desert biomes, and Mediterranean ecosystems were dominated by termites. Temperate grasslands were dominated by omnivores, while temperate forests were dominated by earthworms. On average, estimated litter consumption (relative to total litter input) ranged from a low of 14.9% in deserts to a high of 100.4% in temperate grassland. Litter consumption by soil fauna was greater in grasslands than in forests. This is the first study to estimate the effect of different soil fauna groups on litter consumption and related processes at global scale.
    Matched MeSH terms: Forests
  15. Wang S, Ibrahiem MH, Li M
    Int J Environ Res Public Health, 2022 Dec 18;19(24).
    PMID: 36554915 DOI: 10.3390/ijerph192417034
    As one of the largest payment platforms in China, Alipay, launched a green behavior project called Ant Forest. The purpose of taking this initiative by Alipay is to make the world greener. This mobile application has motivated many users to plant millions of trees. However, minimal studies have been conducted to empirically disclose the factors that motivate Alipay users to participate in Ant Forest. A mixed-method approach is used to examine the factors influencing Alipay users to participate in Ant Forest and the level of satisfaction they got from it. The qualitative method was carried out through a structured questionnaire from 400 Alipay users and qualitative data from 20 users who have applied to Ant Forest and successfully planted trees. Additionally, alongside the mixed method employed to rationalize the relationship highlighted, a multiple regression model was employed to predict the value of a dependent variable (level of satisfaction) based on the value of several independent variables (namely, number of years engaged with Ant Forest activities, age, gender, profession, and education). The empirical results show that intrinsic motivations (enjoyment, social interaction, fulfilment, altruism) and extrinsic motivations (external rewards, competition) influence Alipay users to participate in the Ant Forest project. Further insights are presented in the concluding section for all stakeholders for environmental sustainability among the users of Alipay.
    Matched MeSH terms: Forests
  16. Zuleta D, Arellano G, McMahon SM, Aguilar S, Bunyavejchewin S, Castaño N, et al.
    Glob Chang Biol, 2023 Jun;29(12):3409-3420.
    PMID: 36938951 DOI: 10.1111/gcb.16687
    Accurate estimates of forest biomass stocks and fluxes are needed to quantify global carbon budgets and assess the response of forests to climate change. However, most forest inventories consider tree mortality as the only aboveground biomass (AGB) loss without accounting for losses via damage to living trees: branchfall, trunk breakage, and wood decay. Here, we use ~151,000 annual records of tree survival and structural completeness to compare AGB loss via damage to living trees to total AGB loss (mortality + damage) in seven tropical forests widely distributed across environmental conditions. We find that 42% (3.62 Mg ha-1  year-1 ; 95% confidence interval [CI] 2.36-5.25) of total AGB loss (8.72 Mg ha-1  year-1 ; CI 5.57-12.86) is due to damage to living trees. Total AGB loss was highly variable among forests, but these differences were mainly caused by site variability in damage-related AGB losses rather than by mortality-related AGB losses. We show that conventional forest inventories overestimate stand-level AGB stocks by 4% (1%-17% range across forests) because assume structurally complete trees, underestimate total AGB loss by 29% (6%-57% range across forests) due to overlooked damage-related AGB losses, and overestimate AGB loss via mortality by 22% (7%-80% range across forests) because of the assumption that trees are undamaged before dying. Our results indicate that forest carbon fluxes are higher than previously thought. Damage on living trees is an underappreciated component of the forest carbon cycle that is likely to become even more important as the frequency and severity of forest disturbances increase.
    Matched MeSH terms: Forests
  17. Li T, Cheng H, Li Y, Mou Z, Zhu X, Wu W, et al.
    Sci Total Environ, 2023 Jul 10;881:163204.
    PMID: 37044342 DOI: 10.1016/j.scitotenv.2023.163204
    Tropical primary forests are being destroyed at an alarming rate and converted for other land uses which is expected to greatly influence soil carbon (C) cycling. However, our understanding of how tropical forest conversions affect the accumulation of compounds in soil functional C pools remains unclear. Here, we collected soils from primary forests (PF), secondary forests (SF), oil-palm (OP), and rubber plantations (RP), and assessed the accumulation of plant- and microbial-derived compounds within soil organic carbon (SOC), particulate (POC) and mineral-associated (MAOC) organic C. PF conversion to RP greatly decreased SOC, POC, and MAOC concentrations, whereas conversion to SF increased POC concentrations and decreased MAOC concentrations, and conversion to OP only increased POC concentrations. PF conversion to RP decreased lignin concentrations and increased amino sugar concentrations in SOC pools which increased the stability of SOC, whereas conversion to SF only increased the lignin concentrations in POC, and conversion to OP just increased lignin concentrations in POC and decreased it in MAOC. We observed divergent dynamics of amino sugars (decrease) and lignin (increase) in SOC with increasing SOC. Only lignin concentrations increased in POC with increasing POC and amino sugars concentrations decreased in MAOC with increasing MAOC. Conversion to RP significantly decreased soil enzyme activities and microbial biomasses. Lignin accumulation was associated with microbial properties, whereas amino sugar accumulation was mainly associated with soil nutrients and stoichiometries. These results suggest that the divergent accumulation of plant- and microbial-derived C in SOC was delivered by the distribution and original composition of functional C pools under forest conversions. Forest conversions changed the formation and stabilization processes of SOC in the long run which was associated with converted plantations and management. The important roles of soil nutrients and stoichiometry also provide a natural-based solution to enhance SOC sequestration via nutrient management in tropical forests.
    Matched MeSH terms: Forests
  18. Jaitrong W, Yamane S, Noon-Anant N
    Zootaxa, 2023 Mar 03;5249(4):446-464.
    PMID: 37044753 DOI: 10.11646/zootaxa.5249.4.3
    The Polyrhachis (Myrmatopa) flavicornis species group in Thailand is reviewed. Four species are recognized, of which one species closely related to Polyrhachis constructor Smith, 1857 is described and illustrated as new to science based on the worker caste under the name Polyrhachis longipilosa sp. nov. The queens of P. flavicornis Smith, 1857 and P. constructor, and the males of P. flavicornis and P. varicolor Viehmeyer, 1916 are described. The new species is distributed in western Thailand in the area north of the Isthmus of Kra, while P. constructor is distributed in Malaysia (West Malaysia and Sabah), Indonesia, Singapore, southern and western Thailand. Polyrhachis piliventris Smith, 1857 and Polyrhachis elii Emery, 1900 are synonymized with P. constructor. A key to the Thai species of the Polyrhachis flavicornis species group is given. The type series of P. longipilosa was collected from the canopy of a dry evergreen forest.
    Matched MeSH terms: Forests
  19. Alyan E, Combe T, Awang Rambli DR, Sulaiman S, Merienne F, Muhaiyuddin NDM
    Int J Environ Res Public Health, 2021 Oct 29;18(21).
    PMID: 34769937 DOI: 10.3390/ijerph182111420
    The authors of this paper sought to investigate the impact of virtual forest therapy based on realistic versus dreamlike environments on reducing stress levels. Today, people are facing an increase in stress levels in everyday life, which may be due to personal life, work environment, or urban area expansion. Previous studies have reported that urban environments demand more attention and mental workload than natural environments. However, evidence for the effects of natural environments as virtual forest therapy on stress levels has not yet been fully explored. In this study, a total of 20 healthy participants completed a letter-detection test to increase their stress level and were then randomly assigned to two different virtual environments representing realistic and dreamlike graphics. The participants' stress levels were assessed using two physiological methods that measured heart rate and skin conductance levels and one psychological method through the Profile of Mood States (POMS) questionnaire. These indicators were analyzed using a sample t-test and a one-way analysis of variance. The results showed that virtual forest environments could have positive stress-relieving effects. However, realistic graphics were more efficient in reducing stress. These findings contribute to growing forest therapy concepts and provide new directions for future forest therapy research.
    Matched MeSH terms: Forests
  20. Rojas-Castillo OA, Kepfer Rojas S, Juen L, Montag LFA, Carvalho FG, Mendes TP, et al.
    Conserv Biol, 2024 Feb;38(1):e14172.
    PMID: 37650444 DOI: 10.1111/cobi.14172
    The expansion of oil palm plantations has led to land-use change and deforestation in the tropics, which has affected biodiversity. Although the impacts of the crop on terrestrial biodiversity have been extensively reviewed, its effects on freshwater biodiversity remain relatively unexplored. We reviewed the research assessing the impacts of forest-to-oil palm conversion on freshwater biota and the mitigating effect of riparian buffers on these impacts. We searched for studies comparing taxa richness, species abundance, and community composition of macroinvertebrates, amphibians, and fish in streams in forests (primary and disturbed) and oil palm plantations with and without riparian buffers. Then, we conducted a meta-analysis to quantify the overall effect of the land-use change on the 3 taxonomic groups. Twenty-nine studies fulfilled the inclusion criteria. On average, plantations lacking buffers hosted 44% and 19% fewer stream taxa than primary and disturbed forests, respectively. Stream taxa on plantations with buffers were 24% lower than in primary forest and did not differ significantly from disturbed forest. In contrast, stream community composition differed between forests and plantations regardless of the presence of riparian buffers. These differences were attributed to agrochemical use and altered environmental conditions in the plantations, including temperature changes, worsened water conditions, microhabitat loss, and food and shelter depletion. On aggregate, abundance did not differ significantly among land uses because increases in generalist species offset the population decline of vulnerable forest specialists in the plantation. Our results reveal significant impacts of forest-to-oil palm conversion on freshwater biota, particularly taxa richness and composition (but not aggregate abundance). Although preserving riparian buffers in the plantations can mitigate the loss of various aquatic species, it cannot conserve primary forest communities. Therefore, safeguarding primary forests from the oil palm expansion is crucial, and further research is needed to address riparian buffers as a promising mitigation strategy in agricultural areas.
    Matched MeSH terms: Forests
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