Assessment of Tourism Development Potential Based on Tourism Components in Buffer Zone of Huai Kha Khaeng Wildlife Sanctuary, Uthai Thani Province

Retail investors pay limited attention to alternative gambling activities. More-attentive activities increase, whereas less-attentive activities decrease. However, attention is unobservable. Previous studies proxy gambling attention based on representative gambles, such as lotteries. These proxies incorporate general gambling and representative-gambling attention. Thus, previous studies have reported net effects. This study analyzes the effects of gambling attention on the trading of retail investors in the Stock Exchange of Thailand. Lotteries served as representative gambles. Gambling attention is decomposed into general gambling and lottery-specific components, enabling the study to separately estimate the effects of each component. Lotteries in Thailand offer fixed prizes. However, traditional proxies are not applicable. This study measures attention using the Google search volume index on a lucky-number query. The query is based on a superstitious belief that is unique to the Thai market. Using daily observations from August 6, 2008, to June 30, 2022, which totaled 3,388 observations, this study establishes that gambling attention has a net negative effect. When attention is decomposed, its general gambling and lottery-specific components exhibit positive and negative effects, respectively. Furthermore, the effect on the buying side was stronger than that on the selling side. During the COVID-19 pandemic, the lottery-specific effects became positive. Retail investors responded to lottery-specific attention through stock trading

Insect assemblages attacking seeds and fruits in a rainforest in Thailand

Insect seed predators are important agents of mortality for tropical trees, but little is known about the impact of these herbivores in rainforests. During three years at Khao Chong (KHC) in southern Thailand we reared 17,555 insects from 343.2 kg or 39,252 seeds/fruits representing 357 liana and tree species. A commented list of the 243 insect species identified is provided, with details about their host plants. We observed that: (1) about 43% of identified species can be considered pests. Most were seed eaters, particularly on dry fruits. (2) About 19% of parasitoid species (all Opiinae) for which we could determine whether their primary insect host was a pest or not (all Bactrocera spp. breeding in fruits) can be considered beneficials. (3) The seeds/fruits of about 28% of the plant species in this forest were free of attack. Phyllanthaceae, Rubiaceae, and Meliaceae were attacked relatively infrequently; in contrast, Annonaceae, Fabaceae, Sapindaceae, and Myristicaceae were more heavily attacked. There was no apparent effect of plant phylogeny on rates of attack but heavily attacked tree species had larger basal area in the KHC plot than rarely attacked tree species. (4) Insects reared from fleshy fruits were more likely to exhibit relatively stable populations compared to insects reared from dry fruits, but this was not true of insects reared from dipterocarps, which appeared to have relatively stable populations throughout the study period. We tentatively conclude that insects feeding on seeds and fruits have little effect on observed levels of host abundance in this forest

Latitudinal patterns in stabilizing density dependence of forest communities

Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species1,2, a phenomenon known as conspecific negative density dependence (CNDD)3. A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests4,5, which increases community stabilization, species coexistence and the diversity of local tree species6,7. Previous analyses supporting such a latitudinal gradient in CNDD8,9 have suffered from methodological limitations related to the use of static data10,11,12. Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizing CNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones13. We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity14,15, was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests

Patch metrics of roosting site selection by Lyle’s flying fox (Pteropus lylei Andersen, 1908) in a human-dominated landscape in Thailand

The association between patch metrics and roosting site (n = 31) suitability of Lyle’s flying fox (Pteropus lylei) in 26 Central Eastern and Western provinces of Thailand was quantified. Land use classes with 90-m resolution were identified based on various vegetation and land cover types to calculate patch metrics using FRAGSTATS. Then, Maximum Entropy Modeling (MaxEnt) was performed using patch metrics covariates to produce a predictive potential distribution map. The results indicated that patch contiguity (contiguity index, 63.7%), patch area (29.3%), and patch shape complexity (shape index, 5.7%) are the most influential patch metrics, all of which have negative effects on roosting site suitability. In total, 13,222 small patches were considered highly suitable patches, with a mean area of 0.921 ± 0.698 (SD) ha, which accounted for 122,090 ha (2.04%) of the study area. Roosting sites predicted from the model were consistently associated with occurrences of roosting sites observed in temples; such habitats likely provide shelter from external threats for colonies roosting in a human-dominated landscape

Effects of Fire on Diversity and Aboveground Biomass of Understory Communities in Seasonally Dry Tropical Forest in Western Thailand

Fire is a necessary disturbance in tropical deciduous forests, as it helps clear the understory community and allows regeneration of grasses and forbs for local wildlife. Huai Kha Khaeng Wildlife Sanctuary (HKK) and Huai Thab Salao-Huai Rabum Non-Hunting Area (HTS) are parts of a few places in Southeast Asia with deciduous forests. However, this area was heavily logged up until 1989, followed by a long period of fire suppression. The consequences of these changes on understory communities have not been investigated. Therefore, the current study aimed to examine the understory communities and their aboveground biomass before and after the annual prescribed burns in HKK and HTS. Understory plant composition and biomass were surveyed in November 2018 (before the fire) and May 2019 (three months after the fire) in 128 temporary plots, covering of deciduous dipterocarp forest, mixed deciduous forest, mixed deciduous forest with bamboo, and open area. We identified a total of 480 understory species, including 37 grass species, 214 forb species, 73 shrub species, 153 tree seedling species and three species of bamboo in the study plots. Grasses in the DDF plots were at 72.79 ± 22.41 kg ha−1, accounting for only ten percent of the understory plants in the plots. The understory community in the DDF plots was dominated by shrubs and tree seedlings of competing species, especially after the fire. The results suggested that past logging activities and long-term fire suppression had reduced the number of mature key dipterocarp forests and hindered the regeneration of grasses and forbs. Maintaining the structure of dipterocarp forests and sufficient food sources for the local wildlife species will require more active habitat management of the study areas

Host specificity and interaction networks of insects feeding on seeds and fruits in tropical rainforests

In the tropics, antagonistic seed predation networks may have different properties than mutualistic pollination and seed dispersal networks, but the former have been considerably less studied. We tested whether the structure of antagonistic tripartite networks composed of host plants, insects developing within seeds and fruits, and their insect parasitoids could be predicted from plant phylogenetic distance and plant traits. We considered subsets of the networks (‘subnetworks') at three rainforest locations (Panama, Thailand, Papua New Guinea), based on insect families, plant families or plant functional groups. We recorded 3197 interactions and observed a low percentage of realized interactions, especially in Panama, where insect host specificity was higher than in Thailand or New Guinea. Several factors may explain this, including insect faunal composition, incidence of dry fruits, high fruit production and high occurrence of Fabaceae at the Panamanian site. Host specificity was greater among seed-eaters than pulp-eaters and for insects feeding on dry fruits as opposed to insects feeding on fleshy fruits. Plant species richness within plant families did not influence insect host specificity, but site characteristics may be important in this regard. Most subnetworks were extremely specialized, such as those including Tortricidae and Bruchinae in Panama. Plant phylogenetic distance, plant basal area and plant traits (fruit length, number of seeds per fruit) had important effects on several network statistics in regressions weighted by sampling effort. A path analysis revealed a weak direct influence of plant phylogenetic distance on parasitoid richness, indicating limited support for the ‘nasty host hypothesis'. Our study emphasizes the duality between seed dispersal and seed predation networks in the tropics, as key plant species differ and host specificity tends to be low in the former and higher in the latter. This underlines the need to study both types of networks for sound practices of forest regeneration and conservation

Temporal variability of forest communities: empirical estimates of population change in 4000 tree species

Long-term surveys of entire communities of species are needed to measure fluctuations in natural populations and elucidate the mechanisms driving population dynamics and community assembly. We analysed changes in abundance of over 4000 tree species in 12 forests across the world over periods of 6-28years. Abundance fluctuations in all forests are large and consistent with population dynamics models in which temporal environmental variance plays a central role. At some sites we identify clear environmental drivers, such as fire and drought, that could underlie these patterns, but at other sites there is a need for further research to identify drivers. In addition, cross-site comparisons showed that abundance fluctuations were smaller at species-rich sites, consistent with the idea that stable environmental conditions promote higher diversity. Much community ecology theory emphasises demographic variance and niche stabilisation; we encourage the development of theory in which temporal environmental variance plays a central role

Consistency of demographic trade-offs across 13 (sub)tropical forests

1. Organisms of all species must balance their allocation to growth, survival and recruitment. Among tree species, evolution has resulted in different life-history strategies for partitioning resources to these key demographic processes.Life-history strategies in tropical forests have often been shown to align along a trade-off between fast growth and high survival, that is, the well-known fast–slow continuum. In addition, an orthogonal trade-off has been proposed between tall stature—resulting from fast growth and high survival— and recruit- ment success, that is, a stature−recruitment trade-off. However, it is not clear whether these two independent dimensions of life-history variation structure tropical forests worldwide. 2. We used data from 13 large-scale and long-term tropical forest monitoring plots in three continents to explore the principal trade-offs in annual growth, sur- vival and recruitment as well as tree stature. These forests included relatively undisturbed forests as well as typhoon-disturbed forests. Life-history variation in 12 forests was structured by two orthogonal trade-offs, the growth−survival trade-off and the stature−recruitment trade- off. Pairwise Procrustes analysis revealed a high similarity of demographic relationships among forests. The small deviations were related to differences between African and Asian plots. 3. Synthesis. The fast–slow continuum and tree stature are two independent di- mensions structuring many, but not all tropical tree communities. Our discovery of the consistency of demographic trade-offs and life-history strategies across different forest types from three continents substantially improves our ability to predict tropical forest dynamics worldwide

Dataset and Code Accompanying the Study by Medina-Vega et al. in Nature Ecology & Evolution: Tropical Tree Ectomycorrhiza Are Distributed Independently of Soil Nutrients

<p>This Zenodo repository contains the code and the processed dataset used in the research paper titled "Tropical tree ectomycorrhiza are distributed independently of soil nutrients" published in Nature Ecology & Evolution. In this study, we investigate the distribution and abundance of ectomycorrhizal (EcM) trees in lowland tropical forests and their relationship with soil quality.</p><p><strong>Key Finding</strong>: EcM-associated trees' distribution and abundance in lowland tropical forests are independent of soil quality.</p><p><strong>Contents</strong>:</p><ol><li><strong>Code (</strong>CODE_COARSE_SCALE.R and CODE_FINE_SCALE.R<strong>)</strong>: Contains the R scripts used for data analysis.</li><li><strong>Processed Dataset</strong> (PCs_prop_EcM.csv): Includes the processed data for the fine-scale analysis.</li><li><strong>README</strong>: Provides detailed information on how to use the code, interpret the dataset, and access additional required information.</li></ol><p><strong>Data Access Information</strong>:</p><ul><li>To perform the full analyses, please request additional data from the Principal Investigators (PIs) of the plots.</li><li>ForestGEO plot data can be obtained upon request through the ForestGEO portal at http://ctfs.si.edu/datarequest/.</li><li>Refer to Extended Data Table 1 in the manuscript for a comprehensive list of data sources.</li></ul&gt

Tropical tree ectomycorrhiza are distributed independently of soil nutrients

Mycorrhizae, a form of plant–fungal symbioses, mediate vegetation impacts on ecosystem functioning. Climatic effects on decomposition and soil quality are suggested to drive mycorrhizal distributions, with arbuscular mycorrhizal plants prevailing in low-latitude/high-soil-quality areas and ectomycorrhizal (EcM) plants in high-latitude/low-soil-quality areas. However, these generalizations, based on coarse-resolution data, obscure finer-scale variations and result in high uncertainties in the predicted distributions of mycorrhizal types and their drivers. Using data from 31 lowland tropical forests, both at a coarse scale (mean-plot-level data) and fine scale (20 × 20 metres from a subset of 16 sites), we demonstrate that the distribution and abundance of EcM-associated trees are independent of soil quality. Resource exchange differences among mycorrhizal partners, stemming from diverse evolutionary origins of mycorrhizal fungi, may decouple soil fertility from the advantage provided by mycorrhizal associations. Additionally, distinct historical biogeographies and diversification patterns have led to differences in forest composition and nutrient-acquisition strategies across three major tropical regions. Notably, Africa and Asia’s lowland tropical forests have abundant EcM trees, whereas they are relatively scarce in lowland neotropical forests. A greater understanding of the functional biology of mycorrhizal symbiosis is required, especially in the lowland tropics, to overcome biases from assuming similarity to temperate and boreal regions