Rainforest Research Articles

Forest Restoration and the Zoonotic Vector Anopheles balabacensis in Sabah, Malaysia.

Anthropogenic changes to forest cover have been linked to an increase in zoonotic diseases. In many areas, natural forests are being replaced with monoculture plantations, such as oil palm, which reduce biodiversity and create a mosaic of landscapes with increased forest edge habitat and an altered micro-climate. These altered conditions may be facilitating the spread of the zoonotic malaria parasite Plasmodium knowlesi in Sabah, on the island of Borneo, through changes to mosquito vector habitat. We conducted a study on mosquito abundance and diversity in four different land uses comprising restored native forest, degraded native forest, an oil palm estate and a eucalyptus plantation, these land uses varying in their vegetation types and structure. The main mosquito vector, Anopheles balabacensis, has adapted its habitat preference from closed canopy rainforest to more open logged forest and plantations. The eucalyptus plantations (Eucalyptus pellita) assessed in this study contained significantly higher abundance of many mosquito species compared with the other land uses, whereas the restored dipterocarp forest had a low abundance of all mosquitos, in particular, An. balabacensis. No P. knowlesi was detected by PCR assay in any of the vectors collected during the study; however, P. inui, P. fieldi and P. vivax were detected in An. balabacensis. These findings indicate that restoring degraded natural forests with native species to closed canopy conditions reduces abundance of this zoonotic malarial mosquito vector and therefore should be incorporated into future restoration research and potentially contribute to the control strategies against simian malaria.

Methodological Approach for Assessing Impacts and Recovery of Selectively Logged Forests in Tropical Forests

Ecosystem structure and function depends on the local and regional species pools, climate, geology, and type and frequency of disturbances. Tropical rain forests have long been growing in relatively stable climatic conditions and little disturbances until recent decades, when large-scale of land conversion into croplands and forest impacts by selective logging activities and forest fires have been more frequently observed. Selective logging causes forest degradation, which requires a rigorous monitoring system to control and mitigate forest impacts and recovery. Overtime forest disturbances and recovery can be estimated by using vegetation indices derived from remotely sensed data that enable us to distinguish disturbed from undisturbed forests and estimate the degree of those disturbances. This study aimed to assess the suitability of the Modified Soil Adjusted Vegetation Index (MSAVI) to detect selectively logged forests and estimate the forest recovery structure in a study site in the state of Pará, Eastern Amazon region. We retrieved the MSAVI from Landsat imagery to assess forest impacts by selective logging before and after logging. The estimated MSAVI index before and after logging activities were significantly different and enabled us to distinguish forest recovery structures after selective logging in the study site. Our methodological approach can be used to monitor selective logging activities and support planning of Sustainable Forest Management in tropical regions.

Impact of repeated mass ivermectin administration using a community directed approach on L. loa infection in Chrysops silacea of the rain forest and forest savanna of Cameroon

BackgroundLoiasis is an endemic filarial infection in the rainforest zone of West and Central Africa. Repeated annual community-directed treatment with ivermectin (CDTI) delivered for several years to control onchocerciasis has been shown to reduce the prevalence and intensity of Loiasis in some Loa loa-Onchocerca volvulus co-endemic areas. However, the impact of these multiple rounds of CDTI on entomological indicators of loiasis transmission is not known, and was therefore assessed in this study in areas with contrasting histories of CDTI. MethodsThe study was conducted in the East, North-west and South-west 1 CDTI project sites of Cameroon. Two communities per CDTI project were selected for fly collection and dissection. Ivermectin treatment coverage was documented in these areas, and this was correlated to Chrysops infection and infective rates. A total of 7029 female Chrysops were collected from 6 communities of the 3 CDTI projects (East, North-west, and South-west 1) and from 2 communities in a non-CDTI district (East). ResultsChrysops biting densities and parous rates were significantly reduced in the North-west and South-west sites post-CDTI, while in the East, biting densities were similar in non-CDTI and CDTI sites, with higher parous rates observed in the non-CDTI site. Infection and infective rates in the East non-CDTI site were 4.4% and 1.8% respectively, as compared to 3.3% and 1.3% in the CDTI site after 10 ivermectin rounds (there were no baseline data for the latter). In the North-west site, significant reductions in Chrysops infection and infective rates from 10.2% and 4.2% respectively, to 3.5% and 1.2 (after 9 rounds of ivermectin treatment), were recorded following CDTI. In the South-west, infection rate significantly increased from 1.74% to 2.8% and infective rate remained statistically unchanged after 14 rounds of CDTI (0.45% - 0.40%). Similar trends in Mean Head L3 were observed except in the East site where this indicator was similar in both CDTI and control sites. Only in the North-west site did monthly transmission potentials decrease significantly. ConclusionThis study demonstrated that the impact of repeated annual treatment with ivermectin for the control of onchocerciasis using community directed delivery approach on the entomological indicators of loiasis varies with bioecological zones. Community directed treatment with ivermectin induced a significant reduction in the entomological indicators of loiasis in the North-West project site which lies in forest savanna area. A non-significant decrease was observed in the East project site and in contrast, a significant increase was observed in the South-West 1 project site which both lies in the rainforest zones.

Micrometeorological monitoring reveals that canopy temperature is a reliable trait for the screening of heat tolerance in rice.

Micrometeorological monitoring is not just an effective method of determining the impact of heat stress on rice, but also a reliable way of understanding how to screen for heat tolerance in rice. The aim of this study was to use micrometeorological monitoring to determine varietal differences in rice plants grown under two weather scenarios-Long-term Heat Scenario (LHS) and Normal Weather Scenario (NWS)- so as to establish reliable methods for heat tolerance screening. Experiments were conducted with two heat susceptible varieties-Mianhui 101 and IR64-and two heat tolerant varieties, Quanliangyou 681 and SDWG005. We used staggered sowing method to ensure that all varieties flower at the same time. Our results showed that heat tolerant varieties maintained lower canopy temperature compared to heat susceptible varieties, not just during the crucial flowering period of 10 am to 12 pm, but throughout the entire day and night. The higher stomatal conductance rate observed in heat tolerant varieties possibly decreased their canopy temperatures through the process of evaporative cooling during transpiration. Conversely, we found that panicle temperature cannot be used to screen for heat tolerance at night, as we observed no significant difference in the panicle temperature of heat tolerant and heat susceptible varieties at night. However, we also reported that higher panicle temperature in heat susceptible varieties decreased spikelet fertility rate, while low panicle temperature in heat tolerant varieties increased spikelet fertility rate. In conclusion, the results of this study showed that canopy temperature is probably the most reliable trait to screen for heat tolerance in rice.

Can ethylenediurea (EDU) alter the effects of ozone on the source-sink regulation of nitrogen uptake and remobilization during grain filling period in rice?

Increased surface ozone (O3) pollution seriously threatens crop production, and ethylenediurea (EDU) can alleviate crop yield reduction caused by O3. However, the reason for the decrease in grain nitrogen (N) accumulation caused by O3 and whether EDU serves as N fertilizer remain unclear. An experiment was conducted to investigate the impacts of factorial combinations of O3 enrichment (ambient air plus 60 ppb) and EDU (foliage spray with 450 ppm solutions) on N concentration, accumulation and remobilization in hybrid rice seedlings. Compared to ambient condition, elevated O3 significantly inhibited the N accumulation in vegetative organs during anthesis and grain N accumulation during the maturity stage. Elevated O3 significantly decreased the total N accumulation during anthesis and maturity stages, with a greater impact at the latter stage. The decrease in grain N accumulation caused by O3 was attributed to a decrease in N remobilization of vegetative organs during the grain filling period as well as to a decrease in post-anthesis N uptake. However, there was no significant change in the proportion of N remobilization and N uptake in grain N accumulation. The inhibitory effect of O3 on N remobilization in the upper canopy leaves was greater than that in the lower canopy leaves. In addition, elevated O3 increased the N accumulation of panicles at the anthesis stage, mainly by resulting in earlier heading of rice. EDU only increased N accumulation at the maturity stage, which was mainly attributed to an increase in rice biomass by EDU. EDU had no significant effect on N concentration, N remobilization process, and N harvest index. The findings are helpful to better understand the utilization of N fertilizer by rice under O3 pollution, and can also provide a theoretical basis for sustainable nutrient management to alleviate the negative impact of O3 on crop yield and quality.

Variation of Geochemical Properties of Soils in Tropical Lowland Rainforests in Sri Lanka

Tropical lowland rainforests (TLRFs) of Sri Lanka are considered as diverse ecosystems which play a vital role in climate change mitigation. In recent years, increasing deforestation leads to diminishing their potential ecosystem roles. For efficient forest conservation, knowledge of both above- and below-ground characteristics of TLRFs is required. Currently, above-ground information on TLRFs is sufficiently available but the details on the below-ground characteristics are limited. Therefore, this study was carried out to investigate pedo-geochemical properties of lowland rain forests of Kanneliya (KDN) and Pitadeniya, (PTD) in Sri Lanka. Four sampling plots with 1 ha in size (KDN1, KDN2, PTD1 and PTD2) were established, selecting altitudes of 117, 174, 509, and 618 m asl, respectively. Five representative near-surface (up to 25 cm) samples were collected from each plot for the investigation. Soil pH, electrical conductivity (EC), and cation exchange capacity (CEC) were measured while soil organic matter (SOM) content was determined by (i) Walkey-Black (WB) and (ii) Loss on ignition (LI) methods. Data were analysed by ANOVA and means were compared using Duncan‘s test. All measured parameters were significantly different (P<0.05) among the sampling plots. Soil pH and EC values were ranged between 3.43– 3.78 and 0.28–0.44 dS m-1, respectively. The highest CEC was recorded in PTD2 (11.09±3.44 cmol(+)/kg) whereas the lowest was in PTD1 (5.31±1.26 cmol(+)/kg). The highest SOM was recorded in PTD1 (17.71±4.42% in WB, 18.04±3.98% in LI) whereas the lowest was noted in PTD2 (5.81±3.07% in WB, 8.21±2.13% in LI). According to the comparison made between WB and LI methods, LI method recorded higher SOM content. The actual SOM and volatilizable water in hygroscopic mineral fractions might be the reason for the higher values in LI method. All acquired data were compared with standard interpretation data and accordingly, soils of the measured TLRFs are acidic, non-saline and non-reduced with sufficient soil aeration. Even though, TLRF vegetation produce high amount of biomass, soil CEC and SOM contents are low in the study area due to rapid microbial decomposition and absorption of dense vegetation. There was no linear relationship between measured parameters and altitude. Overall, measured soil chemical properties can be considered as ideal indicators of TLRFs conservation and therefore, it needs to be correlated with above-ground properties for understanding the behaviour of TLRFs responding to conservation strategies. 
 Keywords: Forest conservation, Soil chemical properties, Soil organic matter content, Tropical lowland rainforest

Biogeography of vine thickets and open woodland in subtropical eastern Australia: a case study of three camaenid land snail genera

Dry rainforests and open woodlands occur across much of eastern Australia. However, the biogeographic history of these habitats remains poorly known, especially when compared to nearby moist rainforest areas. Land snails are commonly used as model organisms to understand patterns of origins of regional endemism due to their low vagility. Here we present an analysis of patterns of mitochondrial genetic diversity in three camaenid snail lineages with distributions centred on vine-thicket and open woodland habitats of eastern Queensland, specifically Euryladra from open woodlands, Brigaladra from inland semievergreen vine thickets, and Figuladra from coastal vine thickets. Lineages from habitats west of the Great Dividing Range show relatively low genetic divergence between localities, with particularly low structuring in the open woodland taxon Euryladra. Figuladra from vine-thicket habitats closer to the coast shows relatively deeper genetic divergence, with marked divergences between some upland and lowland areas in south-east Queensland, and across the St Lawrence Gap. This structuring suggests that taxa associated with vine thicket habitats have had a more discernible history of isolation than open woodlands. This said, genetic divergence across many vine thickets patches in lowland coastal regions is also shallow, suggesting many apparently disjunct vine thicket habitats and their associated species also have a recent history of connectivity.

Culicoides Species of the Rain Forest Belt of the Littoral Region of Cameroon: Their Incrimination in the Transmission of Mansonella perstans.

Biting midges belonging to the genus Culicoides are tiny stout-shaped hematophagous insects and are thought to transmit the filarial nematode Mansonella perstans. Little is known about the Culicoides fauna in the rain forest belt of the Littoral Region of Cameroon. This study was designed to investigate the diversity, abundance and distribution of Culicoides spp. and their role as the purported vector(s) of M. perstans. Overnight light trap collections and human landing catches (HLCs) revealed eight species of Culicoides with C. grahamii being the most abundant species followed by C. milnei. Four anthropophilic species (C. inornatipennis, C. grahamii, C. fulvithorax and C. milnei) were determined by the HLCs with a higher abundance in the 4-6 p.m. collections. The drop trap technique and Mp419 LAMP assay confirmed C. milnei to be the most efficient vector in enabling the development of the microfilarial stage to the infective larval form of M. perstans. The LAMP assay also revealed that natural transmission of this nematode is fostered by C. milnei and C. grahamii in the wild. In conclusion, C. milnei was shown to be the main vector of M. perstans in the rain forest belt of the Littoral Region of Cameroon.

Stomatal conductance reduction tradeoffs in maize leaves: A theoretical study.

As the leading global grain crop, maize significantly impacts agricultural water usage. Presently, photosynthesis ( ) in leaves of modern maize crops is saturated with , implying that reducing stomatal conductance ( ) would not affect but reduce transpiration ( ), thereby increasing water use efficiency (WUE). While reduction benefits upper canopy leaves under optimal conditions, the tradeoffs in low light and nitrogen-deficient leaves under nonoptimal microenvironments remain unexplored. Moreover, reduction increases leaf temperature ( ) and water vapor pressure deficit, partially counteracting transpiratory water savings. Therefore, the overall impact of reduction on water savings remains unclear. Here, we use a process-based leaf model to investigate the benefits of reduced in maize leaves under different microenvironments. Our findings show that increases in due to reduction can diminish WUE gains by up to 20%. However, reduction still results in beneficial WUE tradeoffs, where a 29% decrease in in upper canopy leaves results in a 28% WUE gain without loss in . Lower canopy leaves exhibit superior tradeoffs in reduction with 178% gains in WUE without loss in . Our simulations show that these WUE benefits are resilient to climate change.

First Report of False Rust caused by Synchytrium psophocarpi on Winged Bean (Psophocarpus tetragonolobus) in Taiwan.

From September 2020 to January 2021, an unknown disease of winged bean (Psophocarpus tetragonolobus) was reported by local growers in the Toucheng Town, Yilan County (N24.91, E121.85). The disease occurs in all age of winged bean, and the occurrence tended to be higher in humid environment, such as branches in lower canopy or branches in high density. The disease symptoms, which also appeared to be the sign of the pathogen, were spherical pustules in yellow to orange color on the stems, leaves, and pods of winged bean. Severely infected plants also exhibited growth reduction, malformation, and curling of the leaves and pods. According to the disease literature of winged bean, this unknown disease was likely to be the false rust caused by a chytrid pathogen, Synchytrium psophocarpi (UK, CAB International. 1993); and the uredinia-liked pustules could be the sori, which contain numerous ovoid to globose sporangia inside. In order to characterize the pathogen identity, the sori were manually ruptured to assess the size of individual sporangium, which had an average of 26.71 ± 4.25 μm x 26.61 ± 4.60 μm (n=42), similar to the size reported in literature (Drinkall and Price. 1979). To confirm the molecular identity, the full genomic sequences from the small subunit (SSU) to the internal transcribed spacer-1 (ITS-1), 5.8S unit, and ITS-2 were amplified using the primer sets NS3 and ITS4. The 2,263 bp amplicon was cloned and sequenced to reveal the identity (Smith et al. 2014). The BLASTN results matched the SSU of our isolate (MW649126.1) to the Synchytrium minutum (HQ324138.1) with 96% similarity (1,075 out of 1,121 bp in length), Synchytrium decipiens isolate DAOM_87618 (KF160868.1) with 92% similarity (1,215 out of 1,326 bp in length) and S. decipiens isolate AFTOL-ID 634 (DQ536475.1) with 92% similarity (1210 out of 1316 bp in length). Phylogenetic analysis using the SSU sequence revealed this unknown pathogen was the grouped within the clade of Synchytrium genus with 100% bootstrapping confidence (Smith et al. 2014). Accordingly, the pathogen was confirmed to be a Synchytrium chytrid fungus. To complete the Koch's postulates, the sori were collected from infected tissue. After vortexing washing in 1% bleach for surface sterilization, the sori were gently crashed by a plastic tube pestle to harvest sporangia. The sporangia were sprayed onto healthy winged beans cultivated in pots, and the inoculated plants were kept in a moisture bag in 25 °C. While leaf curling and malformation could be observed about 14 days post inoculation, the yellow to orange sori could be observed around 30 to 40 days post inoculation on the whole plants cultivated in pots. The sori were collected to confirm the sporangia and the sequences were identical to the original pathogen. Collectively, this study not only presents the first report for the false rust of winged bean in Taiwan, but also documents the first reference sequence of S. psophocarpi that will be useful for future molecular diagnosis. Since S. psophocarpi has been only reported in tropic regions including Indonesia, Malay Peninsula, Malaysia, Papua New Guinea, and Philippines, this report provides the first observation of S. psophocarpi moving in the subtropic region.

Faunal Diversity and the Ecological Aspects of a Community-Based Fragmented Lowland Rainforest Patch in Western Province, Sri Lanka

Wawekale Rainforest Reserve (WRR) is a primary lowland tropical rainforest area in the Western Province of Sri Lanka, established with diversity, but disturbed by human activities such as rubber cultivation, logging, poaching, chemical release, and the collection of firewood. Visual Encounter Surveys (VES) were conducted for 100 hours in the year 2022, which covered wide habitat distribution. The herpetofaunal diversity was measured in the WRR which can indicate broader ecological shifts, environmental changes, or habitat degradation. Water quality was measured in the WRR area to determine the ecosystem health and human impact. The study reports 171 species in 73 families, including two Critically Endangered (1.17%), six Endangered (3.51%), 16 Vulnerable (9.36%), and 14 Near Threatened (8.19%) species according to the IUCN Red List. The study area showed 51 endemic faunal species in Sri Lanka, which represented 29.83% of endemism. Based on the observations conducted on the herpetofauna diversity, the Shannon-Wiener diversity index (H) was calculated and the overall herpetofauna (H’H) showed high diversity within the forest premises. The water quality of the forest fragment had an influence from anthropogenic activities such as removing forest cover, bathing, washing vehicles, and releasing agro-chemical compounds resulting in high water temperature, basic pH level, high electrical conductivity, and high total dissolved solid conditions. The WRR, designated under protection, exhibits the need for immediate remedial actions to mitigate human-induced pollution and deforestation, emphasizing the critical importance of implementing proactive conservation measures to sustain ecological integrity and preserve biodiversity.

Storm Surges and Sea Level Rise Cluster Hydrological Variables Across a Coastal Forest Bordering a Salt Marsh

AbstractSea level rise and storm surges drive coastal forest retreat and salt marsh expansion. Both salinization and flooding control ecological zonation and ecosystem transition in coastal areas. Hydrological variables, if coupled with ecological surveys, can explain the different stages of coastal forest retreat and marsh encroachment. In this research, long‐term data of a host of hydrological variables collected along transects from marsh to inner forest were analyzed. Linear discriminant analysis (LDA) was used to identify the primary hydrological variables responsible for the forest‐marsh gradient and their seasonal patterns. Water content (WC) in the soil (WC) and groundwater electrical conductivity (EC) were found to be the main variables responsible for the hydrological differences among the sites. Higher values of WC and EC were found in the low‐forest area near the salt marsh, with hydrological differences between forest levels reflected in ecological community structure. In particular, some sites were characterized by high EC while others by high WC values, suggesting significant spatial variations within hundreds of meters. The forested area, relatively flat in elevation, was characterized by limited hydraulic gradients and consequently lateral discharges. These characteristics made the role of groundwater level negligible in driving the hydrological clustering. Seasonal LDA data suggest that the sites are hydrologically different during winter (higher distance among clusters of variables) and similar during summer (low distance among clusters). In the study area, higher rainfall occurs during summer, decreasing groundwater EC in areas characterized by low canopy cover (dying forest). Rainfall moved low forest sites closer to the pristine high forest in the LDA analysis. During storm surge events, the distance between clusters decreased, indicating uniform salinization and flooding across the forest. Therefore, we conclude that ecological zonation in a coastal forest is reflected in seasonal hydrological differences in the absence of storm surges. Storm surges do not produce contrasting hydrological conditions and might not be responsible for ecological differences in the short‐term. On the contrary, differences in hydrological recovery are responsible for forest zonation. An additional analysis carried out using a binary Marsh‐Healthy forest LDA classifier indicates when each site switches from a forest hydrological state to a salt‐marsh hydrological state. Our results are useful for long‐term predictions of the ecological evolution of the forest–salt marsh ecotone.

Comparing tar spot epidemics in high-risk areas in the United States and Honduras

Tar spot of corn is a disease that causes significant production losses in the Americas. However, the dynamics of tar spot epidemics in different countries is currently unknown. We assessed the temporal dynamics of tar spot epidemics from six efficacy trial experiments conducted in the United States (US) (three) and Honduras (three) from 2019 to 2021. Data collected corresponded to different canopy positions (lower, middle and upper). In all experiments and canopies, treatments contributed to reducing disease as compared to non-treated controls. In the US the time from disease onset (y ons ) to maximum disease level (y max ) was longer than in Honduras. In all experiments, the disease developed from the lower to the upper canopy. The logistic model described well the disease progression data in its linear and non-linear form. Overall, the linear rates (r L* ) were lower in the US than in Honduras, but in the US the highest rates occurred in the upper canopy, while in Honduras they occurred in the lower canopy. Logistic non-linear rates were in general higher in the US than in Honduras. Multi-treatment meta-analysis and the effect size showed that y ons , r L* , standardized AUDPC and y max were higher in Honduras than in the US in the lower canopy and higher in the US than Honduras in the upper canopy. The best correlations occurred in the lower canopy in Honduras or the upper canopy in the US. The information generated in this study helped identify differences in epidemiological dynamics in high-risk areas in two countries.

Tracing carbon and nitrogen reserve remobilization during spring leaf flush and growth following defoliation.

Woody plants rely on the remobilization of carbon (C) and nitrogen (N) reserves to support growth and survival when resource demand exceeds supply at seasonally predictable times like spring leaf flush and following unpredictable disturbances like defoliation. However, we have a poor understanding of how reserves are regulated and whether distance between source and sink tissues affects remobilization. This leads to uncertainty about which reserves-and how much-are available to support plant functions like leaf growth. To better understand the source of remobilized reserves and constraints on their allocation, we created aspen saplings with organ-specific labeled reserves by using stable isotopes (13C,15N) and grafting unlabeled or labeled stems to labeled or unlabeled root stocks. We first determined which organs had imported root or stem-derived C and N reserves after spring leaf flush. We then further tested spatial and temporal variation in reserve remobilization and import by comparing 1) upper and lower canopy leaves, 2) early and late leaves, and 3) early flush and re-flush leaves after defoliation. During spring flush, remobilized root C and N reserves were preferentially allocated to sinks closer to the reserve source (i.e., lower vs upper canopy leaves). However, the reduced import of 13C in late versus early leaves indicates reliance on C reserves declined over time. Following defoliation, re-flush leaves imported the same proportion of root N as spring flush leaves, but they imported a lower proportion of root C. This lower import of reserve C suggests that, after defoliation, leaf re-flush rely more heavily on current photosynthate, which may explain the reduced leaf mass recovery of re-flush canopies (31% of initial leaf mass). The reduced reliance on reserves occurred even though roots retained significant starch concentrations (~5% dry wt), suggesting aspen prioritizes the maintenance of root reserves at the expense of fast canopy recovery.

People's Perception and Awareness towards Plant Invasion, Its Impacts on Forest Ecosystem Services and Livelihood: A Tale of Central Himalayas.

Plant invasion is a leading threat to biodiversity, ecosystem services and human wellbeing worldwide. In the central Himalayas intentionally or accidentally introduced invasive alien plant species (IAPS) facilitate their own establishment and spread, which is altering forest structure, vegetation composition, species diversity and livelihood. To understand the perception and awareness amongst local communities about invasive alien and native plants and its effect on local livelihood, a questionnaire-based study was conducted in 10 villages of Nainital district, Uttarakhand, India. Household data of 179 respondents were triangulated with key informants such as community leaders, teachers and older people. A majority of the respondents were found to be more familiar with the native species (Berberis asiatica, Pyracantha crenulata and Rubus ellipticus) than IAPS (Ageratina adenophora and Lantana camara). Both the IAPS negative impacts on native biodiversity, ecosystem services and livelihood. During the last two decades IAPS have encroached on various forests and caused a decrease in native species in the study area. According to the local perception, deforestation, forest fire, climate change, increased transport, light weight seed, no use and grazing etc. have been the main factors behind the spread of IAPS. A. adenophora invaded both chir pine (Pinus roxburghii) and banj oak (Quercus leucotrichophora) forests while L. camara remained more prominent in low elevation open canopy chir pine forest. Uprooting is the primary method used to control IAPS in crop fields and forests. The studied villages have not reported awareness and education programs about the IAPS. Our study demonstrates the wide range of perspectives on the threat posed by IAPS to forest ecosystems and natural resources. Education could help to raise awareness about the issue and could be beneficial in managing and controlling invasion in the Himalayan region.

Diurnal, Seasonal, and Vertical Changes in Photosynthetic Rates in Cinamomum camphora Forests in Subtropical China

The increase in the global atmospheric CO2 concentration is expected to increase the productivity of forests, but the dynamic processes of such increased productivity in the forest canopy remain unclear. In this study, diurnal and seasonal variations and vertical changes in photosynthetic rates were investigated in Camphor tree (Cinnamomum camphora) forests in subtropical China. The effect of photosynthetically active radiation (PAR) and CO2 concentrations on photosynthetic rates were also examined in the studied forests. Results showed the diurnal patterns of photosynthesis exhibited two peaks on sunny days, but only one peak on cloudy days. The daily average photosynthetic rate on cloudy days was approximately 74% of that on sunny days. The photosynthetic rate decreased along the vertical forest canopy profile. If the photosynthetic rate in the upper canopy layer was 100%, the corresponding rates were 83% and 25% in the middle and lower canopy layers, respectively. The rates of dark respiration derived from the PAR response curve were 1.73, 1.25, and 1.0 µmol m−2 s−1 for the upper, middle, and lower canopy layers, respectively. The apparent quantum yield of photosynthesis was 0.0183, 0.0186, and 0.0327 µmol CO2 µmol−1 PAR for the upper, middle, and lower canopy, respectively. The initial slope of the photosynthetic response curve to CO2 was highest in the upper canopy and lowest in the lower canopy. The seasonal variation in photosynthetic rates exhibited a two-peaked pattern at all canopy positions, with the two peaks occurring in June and September. The stand biomass and biomass carbon storage were 144.7 t ha−1 and 71.6 t C ha−1 in the examined forests, respectively. The study provides a scientific reference for future research on accessing carbon sequestration and designing forest management practices, specifically in regulating canopy structure in subtropical regions.

Isolation and characterization of microsatellite markers from Garcinia morella using next generation sequencing technology and cross-species amplification

The fruit-bearing medicinal tree, Garcinia morella, grows in the tropical rain forests of India’s Western Ghats, Indo-Chinese Himalayan regions and Sri Lanka. Its fruit rinds are used as a garnish and in seasoning during food preparation. In order to genetically exploit it and assess diversity, development of microsatellite markers was attempted. We partially sequenced genomic DNA using the Illumina Hiseq 2000 platform and examined sequence data for microsatellite loci. We obtained high-quality 10653 Mbp data and was assembled into 1613263 contigs. A total of 121199 SSRs were discovered, Di nucleotide repeats were predominant (42.5%), followed by mono and tri nucleotide repeats (30.4 and 7.9%, respectively). We were able to design primers for 52901 microsatellites. Genetic analysis of 48 SSR loci, showed PIC values ranging from 0.067 to 0.939 with a mean value of 0.7547. The allele per locus ranged from 2 to 24 with a mean of 13. These microsatellite markers can be employed for genetic diversity analysis, molecular characterization and mapping different traits.

White-water Rafting Tourism Potential at Bukit Baka Bukit Raya National Park Based on The Tourism Suitability Index

Bukit Baka Bukit Raya National Park (BBBRNP) is a national park that functions as a conservation area for flora and fauna of mountainous tropical rain forests as well as a water catchment area for two large rivers, namely the Melawi River (West Kalimantan) and the Katingan River (Central Kalimantan). This natural condition produces potential for BBBRNP as a tourism area, especially for white water rafting. One of the BBBRNP resorts that have the potential to become a tourism area is Belaban Resort, a white-water rafting spot. However, the existing possibility of white-water rafting has not been analyzed measurably. This research aims to determine the Tourism Sustainability Index (TSI) of white-water Rafting at Belaban Resort, BBBRNP. The study was conducted in March 2022. The method for determining the observation location used a purposive sampling technique. Data was analyzed using the Tourism Suitability Index (TSI) analysis. This research consists of ten observation points. The research results show that the suitability index for rafting tourism is included in the v(S1) with a suitability index value of 88.56%.

Effects of Pieris japonica (Ericaceae) dominance on cool temperate forest altered-understory environments and soil microbiomes in Southern Japan.

The number of plants unpalatable to deer increases with increasing deer numbers. In the Kyushu Mountain area of Southern Japan, Pieris japonica (Ericaceae), an unpalatable shrub, has become the monodominant vegetation under evergreen conifer and deciduous broad-leaved tree stands. The monodominance of unpalatable plants in the understory has potential advantages and drawbacks; however, the effects of Pieris dominance are not well understood. To assess the effects of P. japonica dominances on forest environments and ecosystems, we investigated understory environments and soil microbiomes in Pieris-dominant sites. Under the deciduous broad-leaved trees, Pieris dominance leads to considerable Pieris leaf litter and humus weights and low soil bulk density and canopy openness. In the soil fungal community and fungal functional groups, the relative abundance of symbiotrophic fungi, particularly ectomycorrhizal fungi in Pieris-dominant sites were lower than in other-vegetation understory sites and saprotrophic fungi vice versa. Because few seedlings and saplings were found under Pieris shrubs, Pieris dominance in the understory might exclude other plant species. The results of this study will contribute to the Pieris population and forest management following deer overgrazing.

Assessing the invasion potential of five common exotic vine species in temperate Australian rainforests

To compare the capacity of native and exotic vine species established under a rainforest canopy, a comparison of growth rates and resource allocation was made amongst five exotic vine species that are serious and common invaders and two common native vine species under two light conditions reflective of edge and interior canopy conditions. All species experienced heavy reductions in growth parameters in the low-light treatment, but three exotic species showed stronger growth under the low light. All exotic species had higher plasticity in leaf morphology showing a significant increase in SLA under low light. Native vines may have a lower capacity to change leaf morphology in shade, as a result of local adaptation to edge habitats. Higher SLA under both low and high light conditions suggests that exotic vines species are able to exploit a range of forest conditions better than the native species. Three species, Anredera cordifolia, Araujia sericifera and Cardiospermum grandiflorum, appear particularly capable of invading rainforest interiors. Individuals produced few leaves, focusing resources on roots and stems suggesting a response to reach the canopy quickly. With their long-distance seed dispersal, plasticity in leaf SLA and high RGR, these species appear most likely to invade undisturbed rainforest.