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Effects of logging and recovery process on avian richness and diversity in hill dipterocarp tropical rainforest-Malaysia

Husin MZ, Rajpar MN

J Environ Biol, 2015 Jan;36 Spec No:121-7.
PMID: 26591891

The effects of logging and recovery process on avian richness and diversity was compared in recently logged and thirty year post-harvested hill dipterocarp tropical rainforest, using mist-netting method. Atotal of 803 bird individuals representing 86 bird species and 29 families (i.e., 37.90% from recently logged forest and 62.10% from thirty year post-harvested forest) were captured from October 2010 to September, 2012. Twenty one bird species were commonly captured from both types of forests, 37 bird species were caught only in thirty year post-harvested forest and 28 bird species were caught only from recently logged forest. Arachnothera longirostra--Little Spiderhunter, Malacopteron magnum--Rufous-crowned Babbler, Alophoixus phaeocephalus -Yellow-bellied Bulbul and Meiglyptes tukki--Buff-necked Woodpecker were the most abundant four bird species in the thirty year post-harvested forest. On the contrary, seven bird species, i.e., Trichastoma rostratum - White-chested Babbler, Lacedo pulchella - Banded Kingfisher, Picus miniaceus--Banded Woodpecker, Enicurus ruficapillus - Chestnut-naped Forktail, Anthreptes simplex--Plain Sunbird, Muscicapella hodgsoni--Pygmy Blue Flycatcher and Otus rufescens--Reddish Scope Owl were considered as the rarest (i.e., each represented only 0.12%). Likewise, A. longirostra, Pycnonotus eythropthalmos - Spectacled Bulbul, P. simplex--Cream-vented Bulbul and Merops viridis--Blue-throated Bee-eater were the most dominant and Copsychus malabaricus--White-rumped Shama Eurylaimus javanicus--Banded Broadbill /xos malaccensis - Streaked Bulbul and Harpactes diardii--Diard's Trogon (each 0.12%) were the rarest bird species in recently logged forest. CAP analysis indicated that avian species in thirty year post-harvested forest were more diverse and evenly distributed than recently logged forest. However, recently logged forest was rich in bird species than thirty year post- harvested forest. The results revealed that logging and retrieval process affect bird species richness and diversity. However, bird species may respond differently from habitat to habitat, i.e., forest logging causes disturbance of some avian species while recovery process may replace the loss of vegetation and harbour a wide array of avian species richness and diversity.

Matched MeSH terms: Rainforest*
Locomotor constraints favour the evolution of the human pygmy phenotype in tropical rainforests

Venkataraman VV, Yegian AK, Wallace IJ, Holowka NB, Tacey I, Gurven M, et al.

Proc Biol Sci, 2018 11 07;285(1890).
PMID: 30404871 DOI: 10.1098/rspb.2018.1492

The convergent evolution of the human pygmy phenotype in tropical rainforests is widely assumed to reflect adaptation in response to the distinct ecological challenges of this habitat (e.g. high levels of heat and humidity, high pathogen load, low food availability, and dense forest structure), yet few precise adaptive benefits of this phenotype have been proposed. Here, we describe and test a biomechanical model of how the rainforest environment can alter gait kinematics such that short stature is advantageous in dense habitats. We hypothesized that environmental constraints on step length in rainforests alter walking mechanics such that taller individuals are expected to walk more slowly due to their inability to achieve preferred step lengths in the rainforest. We tested predictions from this model with experimental field data from two short-statured populations that regularly forage in the rainforest: the Batek of Peninsular Malaysia and the Tsimane of the Bolivian Amazon. In accordance with model expectations, we found stature-dependent constraints on step length in the rainforest and concomitant reductions in walking speed that are expected to compromise foraging efficiency. These results provide the first evidence that the human pygmy phenotype is beneficial in terms of locomotor performance and highlight the value of applying laboratory-derived biomechanical models to field settings for testing evolutionary hypotheses.

Matched MeSH terms: Rainforest*
Fulltext Ants are the major agents of resource removal from tropical rainforests

Griffiths HM, Ashton LA, Walker AE, Hasan F, Evans TA, Eggleton P, et al.

J Anim Ecol, 2018 Jan;87(1):293-300.
PMID: 28791685 DOI: 10.1111/1365-2656.12728

Ants are diverse and abundant, especially in tropical ecosystems. They are often cited as the agents of key ecological processes, but their precise contributions compared with other organisms have rarely been quantified. Through the removal of food resources from the forest floor and subsequent transport to nests, ants play an important role in the redistribution of nutrients in rainforests. This is an essential ecosystem process and a key energetic link between higher trophic levels, decomposers and primary producers. We used the removal of carbohydrate, protein and seed baits as a proxy to quantify the contribution that ants, other invertebrates and vertebrates make to the redistribution of nutrients around the forest floor, and determined to what extent there is functional redundancy across ants, other invertebrate and vertebrate groups. Using a large-scale, field-based manipulation experiment, we suppressed ants from c. 1 ha plots in a lowland tropical rainforest in Sabah, Malaysia. Using a combination of treatment and control plots, and cages to exclude vertebrates, we made food resources available to: (i) the whole foraging community, (ii) only invertebrates and (iii) only non-ant invertebrates. This allowed us to partition bait removal into that taken by vertebrates, non-ant invertebrates and ants. Additionally, we examined how the non-ant invertebrate community responded to ant exclusion. When the whole foraging community had access to food resources, we found that ants were responsible for 52% of total bait removal whilst vertebrates and non-ant invertebrates removed the remaining 48%. Where vertebrates were excluded, ants carried out 61% of invertebrate-mediated bait removal, with all other invertebrates removing the remaining 39%. Vertebrates were responsible for just 24% of bait removal and invertebrates (including ants) collectively removed the remaining 76%. There was no compensation in bait removal rate when ants and vertebrates were excluded, indicating low functional redundancy between these groups. This study is the first to quantify the contribution of ants to the removal of food resources from rainforest floors and thus nutrient redistribution. We demonstrate that ants are functionally unique in this role because no other organisms compensated to maintain bait removal rate in their absence. As such, we strengthen a growing body of evidence establishing ants as ecosystem engineers, and provide new insights into the role of ants in maintaining key ecosystem processes. In this way, we further our basic understanding of the functioning of tropical rainforest ecosystems.

Matched MeSH terms: Rainforest*
Termites mitigate the effects of drought in tropical rainforest

Ashton LA, Griffiths HM, Parr CL, Evans TA, Didham RK, Hasan F, et al.

Science, 2019 01 11;363(6423):174-177.
PMID: 30630931 DOI: 10.1126/science.aau9565

Termites perform key ecological functions in tropical ecosystems, are strongly affected by variation in rainfall, and respond negatively to habitat disturbance. However, it is not known how the projected increase in frequency and severity of droughts in tropical rainforests will alter termite communities and the maintenance of ecosystem processes. Using a large-scale termite suppression experiment, we found that termite activity and abundance increased during drought in a Bornean forest. This increase resulted in accelerated litter decomposition, elevated soil moisture, greater soil nutrient heterogeneity, and higher seedling survival rates during the extreme El Niño drought of 2015-2016. Our work shows how an invertebrate group enhances ecosystem resistance to drought, providing evidence that the dual stressors of climate change and anthropogenic shifts in biotic communities will have various negative consequences for the maintenance of rainforest ecosystems.

Matched MeSH terms: Rainforest*
Fulltext Vertical stratification of adult mosquitoes (Diptera: Culicidae) within a tropical rainforest in Sabah, Malaysia

Brant HL, Ewers RM, Vythilingam I, Drakeley C, Benedick S, Mumford JD

Malar J, 2016 07 19;15(1):370.
PMID: 27430261 DOI: 10.1186/s12936-016-1416-1

BACKGROUND: Malaria cases caused by Plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques, are increasing rapidly in Sabah, Malaysia. One hypothesis is that this increase is associated with changes in land use. A study was carried out to identify the anopheline vectors present in different forest types and to observe the human landing behaviour of mosquitoes.
METHODS: Mosquito collections were carried out using human landing catches at ground and canopy levels in the Tawau Division of Sabah. Collections were conducted along an anthropogenic disturbance gradient (primary forest, lightly logged virgin jungle reserve and salvage logged forest) between 18:00 and 22:00 h.
RESULTS: Anopheles balabacensis, a vector of P. knowlesi, was the predominant species in all collection areas, accounting for 70 % of the total catch, with a peak landing time of 18:30-20:00 h. Anopheles balabacensis had a preference for landing on humans at ground level compared to the canopy (p

Matched MeSH terms: Rainforest*
Niche separation in flycatcher-like species in the lowland rainforests of Malaysia

Mansor MS, Ramli R

Behav Processes, 2017 Jul;140:121-126.
PMID: 28438691 DOI: 10.1016/j.beproc.2017.04.010

Niche theory suggests that sympatric species reduce interspecific competition through segregation of shared resources by adopting different attack manoeuvres. However, the fact that flycatcher-like bird species exclusively use the sally manoeuvre may thus challenge this view. We studied the foraging ecology of three flycatcher-like species (i.e. Paradise-flycatcher Terpsiphone sp., Black-naped Monarch Hypothymis azurea, and Rufous-winged Philentoma Philentoma pyrhoptera) in the Krau Wildlife Reserve in central Peninsular Malaysia. We investigated foraging preferences of each bird species and the potential niche partitioning via spatial or behavioural segregation. Foraging substrate was important parameter that effectively divided paradise-flycatcher from Black-naped Monarch and Rufous-winged Philentoma, where monarch and philentoma foraged mainly on live green leaves, while paradise-flycatcher foraged on the air. They also exhibited different foraging height preferences. Paradise-flycatcher, for instance, preferred the highest studied strata, while Black-naped Monarch foraged mostly in lower strata, and Rufous-winged Philentoma made use of the lowest strata. This study indicates that niche segregation occurs among sympatric species through foraging substrate and attack manoeuvres selection.

Matched MeSH terms: Rainforest*
Ant diversity as a direct and indirect driver of pselaphine rove beetle (Coleoptera: Staphylinidae) functional diversity in tropical rainforests, Sabah, Malaysian Borneo

Psomas E, Holdsworth S, Eggleton P

J. Morphol., 2018 07;279(7):981-996.
PMID: 29676002 DOI: 10.1002/jmor.20828

Pselaphinae is a species-rich beetle subfamily found globally, with many exhibiting myrmecophily-a symbiotic association with ants. Pselaphine-ant associations vary from facultative to obligate, but direct behavioral observations still remain scarce. Pselaphines are speciose and ecologically abundant within tropical leaf litter invertebrate communities where ants dominate, implying a potentially important ecological role that may be affected by habitat disturbances that impact ants. In this study, we measured and analyzed putative functional traits of leaf litter pselaphines associated with myrmecophily through morphometric analysis. We calculated "myrmecophile functional diversity" of pselaphines at different sites and examined this measure's relationship with ant abundance, in both old growth and logged rainforest sites in Sabah, Borneo. We show that myrmecophile functional diversity of pselaphine beetles increases as ant abundance increases. Old growth rainforest sites support a high abundance of ants, which is associated with a high abundance of probable myrmecophilous pselaphines. These results suggest a potential link between adult morphological characters and the functional role these beetles play in rainforest litter as ecological interaction partners with ants.

Matched MeSH terms: Rainforest*
The ongoing cut-down of the Amazon rainforest threatens the climate and requires global tree planting projects: A short review

Peng W, Sonne C, Lam SS, Ok YS, Alstrup AKO

Environ Res, 2020 02;181:108887.
PMID: 31732170 DOI: 10.1016/j.envres.2019.108887

The Amazon rainforest has sustained human existence for more than 10,000 years. Part of this has been the way that the forest controls regional climate including precipitation important for the ecosystem as well as agroforestry and farming. In addition, the Amazon also affects the global weather systems, so cutting down the rainforest significantly increases the effects of climate change, threatening the world's biodiversity and causing local desertification and soil erosion. The current fire activities and deforestation in the Amazon rainforest therefore have consequences for global sustainability. In the light of this, the current decisions made in Brazil regarding an increase in Amazon deforestation require policy changes if the global ecosystems and biodiversity are not to be set to collapse. There is only one way to move forward and that is to increase efforts in sustainable development of the region including limitation in deforestation and to continuously measure and monitor the development. The G7 countries have offered Brazil financial support for at least 20 million euros for fighting the forest fires but the president denies receiving such financial support and says that it is more relevant to raise new forests in Europe. In fact, this is exactly what is happening in Denmark and China in order to reduce climate change. Such activities should be global and include South America, Europe, Africa and Asia where deforestation is important issue. Forest restoration reduces climate change, desertification, and preserves both the regional tropical and global environment if the wood is not burned at a later stage but instead used in e.g. roads as filling material. Changes are therefore needed through improved international understanding and agreements to better avoid the global climate changes, from cutting down the precious rainforest before it is too late as rainforest cannot be re-planted.

Matched MeSH terms: Rainforest*
Making friends in the rainforest: "negrito" adaptation to risk and uncertainty

Lye TP

Hum Biol, 2013 Feb-Jun;85(1-3):417-44.
PMID: 24297236 DOI: 10.3378/027.085.0320

The so-called negritos adapt not just to a tropical forest environment but also to an environment characterized by perturbations and fluctuations. As with other hunter-gatherers in the region and, indeed, throughout the world, they use both social and ecological methods to enhance their chances of survival in this changing environment: socially, they have developed networks of trading and marriage partners; ecologically, they maintain patches of key resources that are available for future harvesting. As evidenced in the case of the Batek (Orang Asli), patterns of forest structure and composition are sometimes direct outcomes of intentional resource concentration and enrichment strategies. While little of the above is controversial anthropologically, what has drawn some debate is the nature of the relationship with partner societies. Conventional wisdom posits relations of inequality between foragers and "others": foragers and farmers are often construed as hierarchical dyads where foragers supply products or labor to farmers in exchange for agricultural harvests and other trade goods. This kind of adaptation appears to be one of divergent specialization. However, there are cases, such as in the relationship between Batek and Semaq Beri, where both societies follow a roughly similar mode of adaptation, and specialization has not materialized. In sum, while not denying that hierarchy and inequality exist, I suggest that they have to be contextualized within a larger strand of relationships that includes both hierarchy and egality. Further, such relationships are part of the general portfolio of risk reduction strategies, following which access to widely scattered environmental resources, and passage from one location to another, is enhanced not by competing with and displacing neighbors but by maintaining a flexible regime of friendly exchange partners.

Matched MeSH terms: Rainforest*
Fulltext Selective‐logging and oil palm: multitaxon impacts, biodiversity indicators, and trade‐offs for conservation planning

Edwards DP, Magrach A, Woodcock P, Ji Y, Lim NT-, Edwards FA, et al.

Ecol Appl, 2014;24(8):2029-49.
PMID: 29185670 DOI: 10.1890/14-0010.1

Strong global demand for tropical timber and agricultural products has driven large-scale logging and subsequent conversion of tropical forests. Given that the majority of tropical landscapes have been or will likely be logged, the protection of biodiversity within tropical forests thus depends on whether species can persist in these economically exploited lands, and if species cannot persist, whether we can protect enough primary forest from logging and conversion. However, our knowledge of the impact of logging and conversion on biodiversity is limited to a few taxa, often sampled in different locations with complex land-use histories, hampering attempts to plan cost-effective conservation strategies and to draw conclusions across taxa. Spanning a land-use gradient of primary forest, once- and twice-logged forests, and oil palm plantations, we used traditional sampling and DNA metabarcoding to compile an extensive data set in Sabah, Malaysian Borneo for nine vertebrate and invertebrate taxa to quantify the biological impacts of logging and oil palm, develop cost-effective methods of protecting biodiversity, and examine whether there is congruence in response among taxa. Logged forests retained high species richness, including, on average, 70% of species found in primary forest. In contrast, conversion to oil palm dramatically reduces species richness, with significantly fewer primary-forest species than found on logged forest transects for seven taxa. Using a systematic conservation planning analysis, we show that efficient protection of primary-forest species is achieved with land portfolios that include a large proportion of logged-forest plots. Protecting logged forests is thus a cost-effective method of protecting an ecologically and taxonomically diverse range of species, particularly when conservation budgets are limited. Six indicator groups (birds, leaf-litter ants, beetles, aerial hymenopterans, flies, and true bugs) proved to be consistently good predictors of the response of the other taxa to logging and oil palm. Our results confidently establish the high conservation value of logged forests and the low value of oil palm. Cross-taxon congruence in responses to disturbance also suggests that the practice of focusing on key indicator taxa yields important information of general biodiversity in studies of logging and oil palm.

Matched MeSH terms: Rainforest*
Image analysis procedure for the optical scanning of fine-root dynamics: errors depending on the observer and root-viewing window size

Kume T, Ohashi M, Makita N, Kho LK, Katayama A, Endo I, et al.

Tree Physiol, 2018 12 01;38(12):1927-1938.
PMID: 30452737 DOI: 10.1093/treephys/tpy124

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. We proposed a protocol for analyzing whole soil images obtained by an optical scanner that cover depths of 0-210 mm. We tested our protocol using six observers with different experience in studying roots. The observers obtained data from the manual digitization of sequential soil images recorded for a Bornean tropical forest according to the protocol. Additionally, the study examined the potential tradeoff between the soil image size and accuracy of estimates of fine-root dynamics in a simple exercise. The six observers learned the protocol and obtained similar temporal patterns of fine-root growth and biomass with error of 10-20% regardless of their experience. However, there were large errors in decomposition owing to the low visibility of decomposed fine roots. The simple exercise revealed that a smaller root-viewing window (smaller than 60% of the original window) produces patterns of fine-root dynamics that are different from those for the original window size. The study showed the high applicability of our image analysis approach for whole soil images taken by optical scanners in estimating the fine-root dynamics of forest ecosystems.

Matched MeSH terms: Rainforest*
Vertical variation in wood CO2 efflux is not uniformly related to height: measurement across various species and sizes of Bornean tropical rainforest trees

Katayama A, Kume T, Ichihashi R, Nakagawa M

Tree Physiol, 2019 06 01;39(6):1000-1008.
PMID: 30976804 DOI: 10.1093/treephys/tpz022

Limited knowledge about vertical variation in wood CO2 efflux (Rwood) is still a cause of uncertainty in Rwood estimates at individual and ecosystem scales. Although previous studies found higher Rwood in the canopy, they examined several tree species of similar size. In contrast, in the present study, we measured vertical variation in Rwood for 18 trees including 13 species, using a canopy crane for a more precise determination of the vertical variation in Rwood, for various species and sizes of trees in order to examine the factors affecting vertical variation in Rwood and thus, to better understand the effect of taking into account the vertical and inter-individual variation on estimates of Rwood at the individual scale. We did not find any clear pattern of vertical variation; Rwood increased significantly with measurement height for only one tree, while it decreased for two more trees, and was not significantly related with measurement height in 15 other trees. Canopy to breast height Rwood ratio was not related to diameter at breast height or crown ratio, which supposedly are factors affecting vertical variation in Rwood. On average, Rwood estimates at individual scale, considering inter-individual variation but ignoring vertical variation, were only 6% higher than estimates considering both forms of variation. However, estimates considering vertical variation, while ignoring inter-individual variation, were 13% higher than estimates considering both forms of variation. These results suggest that individual measurements at breast height are more important for estimating Rwood at the individual scale, and that any error in Rwood estimation at this scale, due to the absence of any more measurements along tree height, is really quite negligible. This study measured various species and sizes of trees, which may be attributed to no clear vertical variation because factors causing vertical variation can differ among species and sizes.

Matched MeSH terms: Rainforest*
Vertical variations in wood CO2 efflux for live emergent trees in a Bornean tropical rainforest

Katayama A, Kume T, Komatsu H, Ohashi M, Matsumoto K, Ichihashi R, et al.

Tree Physiol, 2014 May;34(5):503-12.
PMID: 24876294 DOI: 10.1093/treephys/tpu041

Difficult access to 40-m-tall emergent trees in tropical rainforests has resulted in a lack of data related to vertical variations in wood CO2 efflux, even though significant variations in wood CO2 efflux are an important source of errors when estimating whole-tree total wood CO2 efflux. This study aimed to clarify vertical variations in wood CO2 efflux for emergent trees and to document the impact of the variations on the whole-tree estimates of stem and branch CO2 efflux. First, we measured wood CO2 efflux and factors related to tree morphology and environment for seven live emergent trees of two dipterocarp species at four to seven heights of up to ∼ 40 m for each tree using ladders and a crane. No systematic tendencies in vertical variations were observed for all the trees. Wood CO2 efflux was not affected by stem and air temperature, stem diameter, stem height or stem growth. The ratios of wood CO2 efflux at the treetop to that at breast height were larger in emergent trees with relatively smaller diameters at breast height. Second, we compared whole-tree stem CO2 efflux estimates using vertical measurements with those based on solely breast height measurements. We found similar whole-tree stem CO2 efflux estimates regardless of the patterns of vertical variations in CO2 efflux because the surface area in the canopy, where wood CO2 efflux often differed from that at breast height, was very small compared with that at low stem heights, resulting in little effect of the vertical variations on the estimate. Additionally, whole-tree branch CO2 efflux estimates using measured wood CO2 efflux in the canopy were considerably different from those measured using only breast height measurements. Uncertainties in wood CO2 efflux in the canopy did not cause any bias in stem CO2 efflux scaling, but affected branch CO2 efflux.

Matched MeSH terms: Rainforest*
Fulltext Key Roles of Dipterocarpaceae, Bark Type Diversity and Tree Size in Lowland Rainforests of Northeast Borneo-Using Functional Traits of Lichens to Distinguish Plots of Old Growth and Regenerating Logged Forests

Thüs H, Wolseley P, Carpenter D, Eggleton P, Reynolds G, Vairappan CS, et al.

Microorganisms, 2021 Mar 05;9(3).
PMID: 33807993 DOI: 10.3390/microorganisms9030541

Many lowland rainforests in Southeast Asia are severely altered by selective logging and there is a need for rapid assessment methods to identify characteristic communities of old growth forests and to monitor restoration success in regenerating forests. We have studied the effect of logging on the diversity and composition of lichen communities on trunks of trees in lowland rainforests of northeast Borneo dominated by Dipterocarpaceae. Using data from field observations and vouchers collected from plots in disturbed and undisturbed forests, we compared a taxonomy-based and a taxon-free method. Vouchers were identified to genus or genus group and assigned to functional groups based on sets of functional traits. Both datasets allowed the detection of significant differences in lichen communities between disturbed and undisturbed forest plots. Bark type diversity and the proportion of large trees, particularly those belonging to the family Dipterocarpaceae, were the main drivers of lichen community structure. Our results confirm the usefulness of a functional groups approach for the rapid assessment of tropical lowland rainforests in Southeast Asia. A high proportion of Dipterocarpaceae trees is revealed as an essential element for the restoration of near natural lichen communities in lowland rainforests of Southeast Asia.

Matched MeSH terms: Rainforest
Fulltext PRELIMINARY STUDY OF SPIDER DIVERSITY IN UITM NEGERI SEMBILAN KUALA PILAH CAMPUS FOREST RESERVE

Farida Hamimi Ahmad Dasran, Nursyazni Abdul Rahim

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):91-96.
MyJurnal

UiTM Negeri Sembilan Kuala Pilah Campus Forest Reserve was a lowland rainforest canopy located in Kampung Beting, Kuala Pilah, which hold various habitats for a wide range of organisms. Many of the species, however, were poorly known and documented. Therefore, a preliminary study was conducted to record the diversity of spider fauna in UiTM Kuala Pilah Campus Forest Reserve in two separate areas using three different methods: hand picking, net sweeping and pitfall traps. The present study resulted in 85 samples of spiders from seven families (Araneidae, Ctenidae, Eutichuridae. Oxyopidae, Pholcidae, Salticidae, and Sparassidae) and 13 genera. There were 29 individuals from four families collected from Site A, and 56 individuals from seven families collected from Site B. Salticidae spiders had dominated both sites with 62% of total samples collected. The second dominant family was Araneidae, which constituted 15% of the samples, followed by Ctenidae (6%), Oxyopidae (6%), Eutichuridae (5%), Sparassidae (4%), and Pholcidae (2%). This ecosystem’s spider fauna was qualitatively rich due to diverse microhabitats that represented the high flora and fauna diversity in UiTM Negeri Sembilan Kuala Pilah Campus Forest Reserve. However, the study did not reflect the full spider inventory as fewer sampling periods and areas were conducted. Therefore, additional sampling activities and study periods are anticipated to submit to the inventory of the organisms.

Matched MeSH terms: Rainforest
Lithological constraints on resource economies shape the mycorrhizal composition of a Bornean rain forest

Weemstra M, Peay KG, Davies SJ, Mohamad M, Itoh A, Tan S, et al.

New Phytol, 2020 10;228(1):253-268.
PMID: 32436227 DOI: 10.1111/nph.16672

Arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) produce contrasting plant-soil feedbacks, but how these feedbacks are constrained by lithology is poorly understood. We investigated the hypothesis that lithological drivers of soil fertility filter plant resource economic strategies in ways that influence the relative fitness of trees with AMF or EMF symbioses in a Bornean rain forest containing species with both mycorrhizal strategies. Using forest inventory data on 1245 tree species, we found that although AMF-hosting trees had greater relative dominance on all soil types, with declining lithological soil fertility EMF-hosting trees became more dominant. Data on 13 leaf traits and wood density for a total of 150 species showed that variation was almost always associated with soil type, whereas for six leaf traits (structural properties; carbon, nitrogen, phosphorus ratios, nitrogen isotopes), variation was also associated with mycorrhizal strategy. EMF-hosting species had slower leaf economics than AMF-hosts, demonstrating the central role of mycorrhizal symbiosis in plant resource economies. At the global scale, climate has been shown to shape forest mycorrhizal composition, but here we show that in communities it depends on soil lithology, suggesting scale-dependent abiotic factors influence feedbacks underlying the relative fitness of different mycorrhizal strategies.

Matched MeSH terms: Rainforest
Fulltext Rattan (Calamoideae) Diversity and Biomass Change in Different Habitat Types During Two Years

Ruppert N, Mansor A, Sah SA

Trop Life Sci Res, 2017 Jan;28(1):33-44.
PMID: 28228915 MyJurnal DOI: 10.21315/tlsr2017.28.1.3

Rattans (subfamily Calamoideae) are an important component of the forests of the Old World. However, few studies have been conducted on the distribution of these abundant palms within different habitats, specifically in Peninsular Malaysia. This study was aimed at assessing rattan diversity, abundance and biomass change across two different habitat types, namely, dipterocarp forests and fresh-water swamps within the Segari Melintang Forest Reserve, Perak, within two years. All rattan stems within five 100 m × 100 m sized study plots (A-E) of the two habitat types were counted in 2011 and 2013, and Shannon-Wiener diversity indices (H') and Bray-Curtis dissimilarity indices were calculated. A total of 11 species from 5 genera (161 stems ha(-1)) were sampled. Rattan abundance was higher in all swamp plots; however, rattan diversity (H') was highest in the dipterocarp plot (D: H' (2011)1.79; H' (2013)1.84). Bray-Curtis indices of rattan abundance (highest similarity in swamp: plot BC(2011) 0.484, BC(2013) 0.262) and biomass were highest for study plots with the same vegetation types in both years. For rattan biomass, the most similar plot pairs changed during the years: dipterocarp plots A and D were most similar in 2011 (0.509), and swamp plots B and C were most similar in 2013 (0.282). This study helped contribute information regarding the distribution and dynamics of rattans in a primary rainforest of Peninsular Malaysia.

Matched MeSH terms: Rainforest
How individual links affect network stability in a large-scale, heterogeneous metacommunity

Brodie JF, Mohd-Azlan J, Schnell JK

Ecology, 2016 Jul;97(7):1658-1667.
PMID: 27859156 DOI: 10.1890/15-1613.1

Elucidating how dispersal and landscape connectivity influence metacommunity stability will shed light on natural processes structuring ecosystems and help prioritize conservation actions in an increasingly fragmented world. Much of the theoretical and mathematical development of the metacommunity concept has been based on simplified experimental systems or simulated data. We still have limited understanding of how variation in the habitat matrix and species-specific differences in dispersal ability contribute to metacommunity dynamics in heterogeneous landscapes. We model a metacommunity of rainforest mammals in Borneo, a tropical biodiversity hotspot, where protected areas are increasingly isolated by ongoing habitat disturbance and loss. We employ a combination of hierarchical models of local abundance, circuit-theory-based dispersal analysis, and metapopulation models. Our goal was to understand which landscape links were the most important to metapopulation persistence and metacommunity stability. Links were particularly important if they were short and connected two large patches. This was partly because only the very shortest links could be traversed by poorly dispersing species, including small herbivores such as chevrotains (Tragulus spp.) and porcupines. Links that join large patches into a "super-patch" may also promote island-mainland rather than Levins-type metapopulation dynamics for good dispersers, particularly large carnivores such as clouded leopards (Neofelis diardi) and sun bears (Helarctos malayanus), reducing metapopulation extinction risk and thereby enhancing metacommunity stability. Link importance to metacommunity stability was highly correlated between heterogeneous and homogeneous landscapes. But link importance to metapopulation capacity varied strongly across species, and the correlation between heterogeneous and homogeneous landscape matrix scenarios was low for poorly dispersing taxa. This suggests that the environmental conditions in the area between habitat patches, the landscape matrix, is important for assessing certain individual species but less so for understanding the stability of the entire metacommunity.

Matched MeSH terms: Rainforest
Fulltext Ant mosaics in Bornean primary rain forest high canopy depend on spatial scale, time of day, and sampling method

Yusah KM, Foster WA, Reynolds G, Fayle TM

PeerJ, 2018;6:e4231.
PMID: 29423344 DOI: 10.7717/peerj.4231

Background: Competitive interactions in biological communities can be thought of as giving rise to "assembly rules" that dictate the species that are able to co-exist. Ant communities in tropical canopies often display a particular pattern, an "ant mosaic", in which competition between dominant ant species results in a patchwork of mutually exclusive territories. Although ant mosaics have been well-documented in plantation landscapes, their presence in pristine tropical forests remained contentious until recently. Here we assess presence of ant mosaics in a hitherto under-investigated forest stratum, the emergent trees of the high canopy in primary tropical rain forest, and explore how the strength of any ant mosaics is affected by spatial scale, time of day, and sampling method.
Methods: To test whether these factors might impact the detection of ant mosaics in pristine habitats, we sampled ant communities from emergent trees, which rise above the highest canopy layers in lowland dipterocarp rain forests in North Borneo (38.8-60.2 m), using both baiting and insecticide fogging. Critically, we restricted sampling to only the canopy of each focal tree. For baiting, we carried out sampling during both the day and the night. We used null models of species co-occurrence to assess patterns of segregation at within-tree and between-tree scales.
Results: The numerically dominant ant species on the emergent trees sampled formed a diverse community, with differences in the identity of dominant species between times of day and sampling methods. Between trees, we found patterns of ant species segregation consistent with the existence of ant mosaics using both methods. Within trees, fogged ants were segregated, while baited ants were segregated only at night.
Discussion: We conclude that ant mosaics are present within the emergent trees of the high canopy of tropical rain forest in Malaysian Borneo, and that sampling technique, spatial scale, and time of day interact to determine observed patterns of segregation. Restricting sampling to only emergent trees reveals segregatory patterns not observed in ground-based studies, confirming previous observations of stronger segregation with increasing height in the canopy.

Matched MeSH terms: Rainforest
Fulltext Phenotypic Characterization and Comparative Genomic Analysis of Novel Salmonella Bacteriophages Isolated from a Tropical Rainforest

Mutusamy P, Banga Singh KK, Su Yin L, Petersen B, Sicheritz-Ponten T, Clokie MRJ, et al.

Int J Mol Sci, 2023 Feb 12;24(4).
PMID: 36835084 DOI: 10.3390/ijms24043678

Salmonella infections across the globe are becoming more challenging to control due to the emergence of multidrug-resistant (MDR) strains. Lytic phages may be suitable alternatives for treating these multidrug-resistant Salmonella infections. Most Salmonella phages to date were collected from human-impacted environments. To further explore the Salmonella phage space, and to potentially identify phages with novel characteristics, we characterized Salmonella-specific phages isolated from the Penang National Park, a conserved rainforest. Four phages with a broad lytic spectrum (kills >5 Salmonella serovars) were further characterized; they have isometric heads and cone-shaped tails, and genomes of ~39,900 bp, encoding 49 CDSs. As the genomes share a <95% sequence similarity to known genomes, the phages were classified as a new species within the genus Kayfunavirus. Interestingly, the phages displayed obvious differences in their lytic spectrum and pH stability, despite having a high sequence similarity (~99% ANI). Subsequent analysis revealed that the phages differed in the nucleotide sequence in the tail spike proteins, tail tubular proteins, and portal proteins, suggesting that the SNPs were responsible for their differing phenotypes. Our findings highlight the diversity of novel Salmonella bacteriophages from rainforest regions, which can be explored as an antimicrobial agent against MDR-Salmonella strains.

Matched MeSH terms: Rainforest

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