Search

A population genomic approach was employed to investigate the diversity within species to create a more robust, lineage-specific conservation strategy for an endangered orchid. Pleione formosana is a species native to southeastern China and Taiwan, where it is distributed at an altitude range of 1,200–2,500 m the foggy mountain area and grows in mosses on half-shaded rocks or tree trunks. To identify whether the level of genetic diversity in the species, we used genotyping by sequencing (GBS) to analysis the sub-populations of the species. Fifty-eight individuals of P. formosana were sampled from a total of nine populations within continental island Taiwan and three populations in China as outgroup. Treatment of all samples involved five major steps: sample preparation, library assembly, sequencing, SNP calling and diversity analysis. GBS markers confirmed the China outgroup as distinct, and provided resolution of two clusters of population genetic structure in Taiwan. Outliers provide higher genetic differentiation, and some GBS tags associated with climatic factor were found. Genomic diversity identified among the three clusters suggests that conservation of this species will be best served by considering them as three evolutionary significant units (ESUs). This approach will maximize evolutionary potential among all species during increased isolation and environmental change. According to the genetic consequences, restoration strategies should be carried out in all populations to preserve genetic diversity and evolutionary potential for different environmental factors.

The spatial distribution of tree species in the forest is key to understanding species coexistence concerning their realized niche. Previous research has shown that forest community composition differs in Lanjenchi Forest Dynamics Plot (FDP) and is likely to be caused by the strength of the northeast monsoon wind. However, relationships between species and other environmental factors are not completely understood. We investigated tree species-habitat associations in Lanjenchi asking how topographic habitat affects forest structure and composition, and we classified the plot into topographic habitat using Multivariate Regression Trees based on the forest community composition and topography. Then, based on metrics of forest structure, we used the torus translation test to evaluate the degree of tree species-habitat association. Three habitats were identified in Lanjenchi and can be classified into windward, intermediate, and leeward habitats based on wind exposure value and aspect. Moreover, 81% of species had a strong positive association with one of the three habitats. Based on the strength of habitat association, the tree species can be divided into six categories. Among these categories, windward species are most abundant in Lanjenchi but are some of the rarest species in Taiwan. These results indicated that the northeast monsoon wind is an essential factor that shapes species distribution in the Lanjenchi, especially at the windward habitats. The northeast monsoon wind creates a unique niche allowing many regionally rare species to dominate these habitats in tropical Taiwan.

Accurate reconstructions of past environments are critical and urgent because they can help understand how modern environments might respond to current climatic and land-use changes. However, the effect of microbial degradation and consequential modification in plant-derived-biomarkers during the early degradation phase is not yet apparent, that might bias the paleoenvironmental investigation. In this regard, a litterbag experiment was conducted to reveal the microbial effects on n-alkane-associated biomarker changes associated with three habitats (ravine, windward, and leeward) in a lowland subtropical rainforest in southern Taiwan. Freshly collected leaves of plant species Iles rotunda, Ficus benjamina, and Castanopsis carlesii were distributed in the habitat leaf litterbag experiment for 15 and 75 days incubation, respectively. The results revealed that the average leaf decomposition rate was 19.4% ± 6.4% during the first 15 days and 39% ± 11% within 75 days incubation for all leaves. The overall leaf mass degradation of I. rotunda, F. benjamina and C. carlesii in the ravine after 75 days was 58%, 51% and 41%, respectively, which were higher than those in the windward (28%, 36% and 38%) and leeward habitats (35%, 26% and 42%, respectively) indicating higher decomposition rate in the ravine habitat than the others. The predominant n-alkanes in I. rotunda were C

Symbiotic nitrogen (N)-fixing trees can provide large quantities of new N to ecosystems, but only if they are sufficiently abundant. The overall abundance and latitudinal abundance distributions of N-fixing trees are well characterised in the Americas, but less well outside the Americas. Here, we characterised the abundance of N-fixing trees in a network of forest plots spanning five continents, ~5,000 tree species and ~4 million trees. The majority of the plots (86%) were in America or Asia. In addition, we examined whether the observed pattern of abundance of N-fixing trees was correlated with mean annual temperature and precipitation. Outside the tropics, N-fixing trees were consistently rare in the forest plots we examined. Within the tropics, N-fixing trees were abundant in American but not Asian forest plots (~7% versus ~1% of basal area and stems). This disparity was not explained by mean annual temperature or precipitation. Our finding of low N-fixing tree abundance in the Asian tropics casts some doubt on recent high estimates of N fixation rates in this region, which do not account for disparities in N-fixing tree abundance between the Asian and American tropics. Synthesis. Inputs of nitrogen to forests depend on symbiotic nitrogen fixation, which is constrained by the abundance of N-fixing trees. By analysing a large dataset of ~4 million trees, we found that N-fixing trees were consistently rare in the Asian tropics as well as across higher latitudes in Asia, America and Europe. The rarity of N-fixing trees in the Asian tropics compared with the American tropics might stem from lower intrinsic N limitation in Asian tropical forests, although direct support for any mechanism is lacking. The paucity of N-fixing trees throughout Asian forests suggests that N inputs to the Asian tropics might be lower than previously thought.

Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how mycorrhizal associations correlate with the latitudinal tree beta-diversity remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test how AM and EcM trees contribute to total beta-diversity and its components (turnover and nestedness) of all trees. We find AM rather than EcM trees predominantly contribute to decreasing total beta-diversity and turnover and increasing nestedness with increasing latitude, probably because wide distributions of EcM trees do not generate strong compositional differences among localities. Environmental variables, especially temperature and precipitation, are strongly correlated with beta-diversity patterns for both AM trees and all trees rather than EcM trees. Results support our hypotheses that latitudinal beta-diversity patterns and environmental effects on these patterns are highly dependent on mycorrhizal types. Our findings highlight the importance of AM-dominated forests for conserving global forest biodiversity., The relationship of mycorrhizal associations with latitudinal gradients in tree beta-diversity is unexplored. Using a global dataset approach, this study examines how trees with arbuscular mycorrhizal and ectomycorrhizal associations contribute to latitudinal beta-diversity patterns and the environmental controls of these patterns.

ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plot-based ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science.

Macrophages play an indispensable role in the host immune defense. Macrophages can undergo polarization into classically (M1) and alternatively (M2) activated macrophages. M1 macrophages activate immune and inflammatory response, while M2 macrophages are involved in tissue remodeling. Mahonia oiwakensis (Mo) is a herbal medicine in Asia used for its anti-inflammatory and analgesic properties; however, the mechanism is unclear. This study analyzed the effect of Mo extracts and its effects on the polarization of both macrophage RAW264.7 cells and mouse splenic macrophages. Water (Mo-W) and EtOH extracts (Mo-E) did not change the viability of RAW264.7 cells, whereas Mo-E inhibited nitric oxide (NO) production. The major compounds, berberine and palmatine, decreased the viability and NO levels of cells. The secretion of inflammatory cytokines CXCL16, IL-6, L-selectin, MCP1, RANTES, and sTNF-R1 was downregulated, whereas the production of vascular endothelial growth factor (VEGF) was upregulated by Mo-E, berberine, and palmatine treatments. Mo-E, berberine, and palmatine stimulated the expression of macrophage CD68 and M2-type CD204 markers, decreased M1-mediated p-STAT1 and NF-κB, and increased M2-mediated p-STAT6 expression. Similar effects on M2 polarization were also observed in splenic macrophages from mice. In conclusion, Mo-E, berberine, and palmatine modulated macrophages through the suppression of M1-mediated inflammation and the recruitment of M2-mediated VEGF secretion and STAT6 expression.

The size distribution of trees in natural forests is a fundamental attribute of forest structure. Previous attempts to model tree size distributions using simple functions (such as power or Weibull functions) have had limited success, typically overestimating the number of large stems observed. We describe a model which assumes that the dominant mortality process is asymmetric competition when trees are smaller, and size-independent processes (e.g. disturbance) when trees are larger. This combination of processes leads to a size distribution which takes the form of a power distribution in the small tree phase and a Weibull distribution in the large tree phase. Analyses of data from four large-scale ( 24 ha each) subtropical and temperate forest plots totalling 99 ha and approximately 0.4 million trees provide support for this model in two respects: (a) the combined function provided unbiased predictions and (b) power-law functions fitted to small trees had exponents that deviated from the universal exponent of 22 predicted by metabolic scaling theory, gradually decreasing from subtropical evergreen to temperate deciduous forests along the latitudinal gradient.

Aim We identify the main forest vegetation types in Taiwan, provide their formal definitions and describe their species composition, habitat affinities and distribution. Location Taiwan. Methods A data set of 9822 vegetation plots with environmental characteristics recorded in the field or derived from digital maps in GIS was compiled from historical literature and an extensive field survey. Using expert knowledge, 6574 of these plots were used to build a classification into broad vegetation types. The units of the resulting classification were formally defined using a Cocktail determination key, which can be used for the automatic assignment of new vegetation plots to these vegetation types. Results Twelve vegetation types of zonal forests and nine types of azonal forests were distinguished. Zonal types in the subtropical region, from high mountains to foothills, are Juniperus subalpine coniferous woodland, Abies–Tsuga upper-montane coniferous forest, Chamaecyparis montane mixed cloud forest, Fagus montane deciduous broad-leaved cloud forest, Quercus montane evergreen broad-leaved cloud forest, Machilus–Castanopsis sub-montane evergreen broad-leaved forest, Phoebe–Machilus sub-montane evergreen broad-leaved forest and Ficus–Machilus semi-evergreen foothill forest. Zonal types in the tropical region, from high mountains to foothills, are Pasania–Elaeocarpus montane evergreen broad-leaved cloud forest, Drypetes–Helicia sub-montane evergreen broad-leaved forest, Dysoxylum–Machilus foothill evergreen broad-leaved forest and Aglaia–Ficus foothill evergreen broad-leaved forest. Azonal types are Illicium–Cyclobalanopsis tropical winter monsoon forest, Pyrenaria–Machilus subtropical winter monsoon forest, Diospyros–Champereia tropical rock-outcrop forest, Zelkova–Quercus subtropical rock-outcrop forest, Pinus successional woodland, Alnus successional woodland, Trema–Mallotus successional woodland, Scaevola–Hibiscus seashore woodland and Kandelia mangrove. Conclusions The diversity of forest vegetation in Taiwan is strongly structured by the temperature and moisture gradient. Along the temperature gradient, five altitudinal zones can be recognized. Azonal forest types develop at sites affected by the winter monsoon, on steep slopes, rocky soils, in seashore saline habitats and in places disturbed by fire, landslides and human activities. Zonal vegetation contains a higher ratio of endemic and Pacific species and occurs in wetter habitats, whereas azonal vegetation contains co-existing species from different regions and usually occurs in drier habitats.

Coastal salt marshes sequester carbon at high rates relative to other ecosystems and emit relatively little methane particularly compared to freshwater wetlands. However, fluxes of all major greenhouse gases (N 2 O, CH 4 , and CO 2 ) need to be quantified for accurate assessment of the climatic roles of these ecosystems. Anthropogenic nitrogen inputs (via run-off, atmospheric deposition, and wastewater) impact coastal marshes. To test the hypothesis that a pulse of nitrogen loading may increase greenhouse gas emissions from salt marsh sediments, we compared N 2 O, CH 4 and respiratory CO 2 fluxes from nitrate-enriched plots in a Spartina patens marsh (receiving single additions of NaNO 3 equivalent to 1.4 g N m −2 ) to those from control plots (receiving only artificial seawater solutions) in three short-term experiments (July 2009, April 2010, and June 2010). In July 2009, we also compared N 2 O and CH 4 fluxes in both opaque and transparent chambers to test the influence of light on gas flux measurements. Background fluxes of N 2 O in July 2009 averaged −33 μmol N 2 O m −2 day −1 . However, within 1 h of nutrient additions, N 2 O fluxes were significantly greater in plots receiving nitrate additions relative to controls in July 2009. Respiratory rates and CH 4 fluxes were not significantly affected. N 2 O fluxes were significantly higher in dark than in transparent chambers, averaging 108 and 42 μmol N 2 O m −2 day −1 respectively. After 2 days, when nutrient concentrations returned to background levels, none of the greenhouse gas fluxes differed from controls. In April 2010, N 2 O and CH 4 fluxes were not significantly affected by nitrate, possibly due to higher nitrogen demands by growing S. patens plants, but in June 2010 trends of higher N 2 O fluxes were again found among nitrate-enriched plots, indicating that responses to nutrient pulses may be strongest during the summer. In terms of carbon equivalents, the highest average N 2 O and CH 4 fluxes observed, exceeded half the magnitude of typical daily net carbon sequestration rates by salt marshes. Thus, anthropogenic additions of nitrate to coasts can substantially alter N 2 O fluxes from marshes, although substantial temporal variation in these fluxes was observed. To better assess the climatic roles of salt marshes, greenhouse gas emissions need to be studied in the context of chronic nitrogen loads that impact many coastal ecosystems.

In order to reveal the characteristics of the vegetation affected by monsoons at the northern border of Paleotropics, a tree-by-tree census was conducted in the lowland forests in the southernmost Taiwan (Nanjenshan) and an adjacent islet (Lanyu). The census recorded a total of 109,060 individuals (≥1-cm diameter at breast height) belonging to 255 vascular tree species in 1330 quadrats (10 × 10 m). Two-way Indicator Species Analysis first classified forest types into two groups, Lanyu and Nanjenshan, reflecting biogeographical differences. Five subgroups were further classified, showing correlations with topographic position indices. Forests located on wind-exposed slopes, regardless of elevations, were characterised by low canopy height, high stem density, high proportion of small stems, and high proportion of warm-temperate-related species, compared with the wind-sheltered communities. However, there were no significant differences in basal area and species diversity. In comparison with other tropical forests, our forests are characterised by high stem density, low diversity and a lack of the pan-Paleotropical dominant Dipterocarpaceae. In conclusion, vegetation in the studied regions not only showed a transition characteristic between Paleotropics and Holarctic Kingdoms in terms of composition, but also showed differentiations caused by their biogeographical history and the interaction between topographic positions and wind stress from monsoons.

Spatial patterns of trees in a lowland rainforest at Nanjen Lake, southern Taiwan were evaluated. Among the 91 species with more than 15 individuals in the 1.61-ha plot, 90.1% species showed an aggregated distribution pattern, and 8.8% species were randomly distributed at the 4 m scale. Along the distance scales, 71.4% species kept aggregated distribution pattern, and only one species remained randomly distributed at all distance scales. Rare species tended to be more aggregated than the common species. As for trees in different size classes, 40.9% highly aggregated species became less aggregated or even randomly distributed with the increase of tree size, while 9.1% species had an inverse pattern. As for trees in the size class ≥ 8 cm diameter, 68.2% species were randomly distributed and only 29.6% species were aggregated. No species displayed a regular pattern in any size class. There were four major habitat types in the study plot, including ridge, mid-slope, valley and streamside types. Our results suggested that the distribution patterns of most species within the Nanjen Lake plot were related to habitat heterogeneity, such that some species were only distributed along the streamside and some species could only be found on the ridge top. Other factors, such as dispersal limitation, might also play a role in determining the distribution patterns of trees.

Spatial patterns of trees in a lowland rainforest in the 5.88-ha Lanjenchi plot of the southernmost Taiwan were evaluated. Among the 88 species with more than 15 individuals, 87.5% had an aggregated distribution pattern, and 9.1% species were randomly distributed. Rare species tended to be more aggregated than common species at all distance scales. As for different DBH size classes, 35.5% species shifted from highly aggregated patterns to a low level of aggregation or random distribution with an increase in tree size, and 11.3% species had an inverse pattern. When comparing spatial patterns among different habitats within the plot, the aggregation intensity increased along a wind-stress gradient from the sheltered creek to the most exposed slopes. No species displayed a regular pattern in any size class or habitat type. This study revealed that distribution of most species within the Lanjenchi forest was related to habitat heterogeneity. Other factors, such as dispersal limitation, however, may also play a role in determining the distribution patterns.

The forest in Lanjenchi is a remnant patch of subtropical rainforests in southern Taiwan. In 1998, the previous Lanjenchi plot was enlarged from 3 ha to 5.88 ha in order to include more topographical variation and understand how the gradient of wind stress controls forest structure and species composition. All free-standing woody plants in these plots with diameter ≥ 1 cm were identified, measured, tagged and mapped. A total of 60,146 individuals belonging to 136 vascular tree species in 83 genera and 42 families was recorded. Families with the largest cumulative basal areas were Fagaceae, Theaceae, Araliaceae, Aquifollaceae, Lauraceae and Illiciaceae. The size-class distribution of all species showed that most species were in good recruitment patterns with the most stems in small size classes. The results of two-way indicator species analysis (TWINSPAN) classified the sampling plots into four forest and habitat types: 1. Rhaphiolepis indica var. hiiranensis - Illicium arborescens (Windward I) type; 2. Cinnamomum brevipedunculatum - Illicium arborescens (Windward II) type; 3. Sloanea formosana - Ilex cochinchinensis (Leeward) type; and 4. Glycosmis citrifolia - Helicia formosana (Creek) type. The forest composition changes formed a sequence on the topographic gradient from the most exposed windward ridges and north-east-facing slopes to more sheltered leeward footslopes and creeks. Further studies using detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) confirmed the results of TWINSPAN, and showed the important roles of the topographic variables in the distribution of most tree species.

A permanent 2.21 ha plot of lowland subtropical rainforest was established at Nanjen Lake of the Nanjenshan Nature Reserve in southern Taiwan. All free-standing woody plants in the plot with DBH  1 cm were identified, measured, tagged, and mapped. A total of 120 tree species (21,592 stems), belonging to 44 families and 83 genera, was recorded. The community structure was characterized by a relative dominance of Castanopsis carlesii in the canopy, Illicium arborescens in the subcanopy, and Psychotria rubra in the understory. The dominant families were Fagaceae, Illiciaceae, Aquifoliaceae, Lauraceae and Theaceae. However, typical species of lowland area in Taiwan, such as members of Euphorbiaceae and Moraceae, were relatively rare. Thus, floristic composition of this area was comparable with that found in some of the subtropical rain forests or even warm-temperate rain forests of the Central Range in Taiwan. The analysis of size-class distributions of individual species showed good recruitment patterns with a rich sapling bank for each species. TWINSPAN analysis revealed four distinct groups of samples, with the ridge top and northwest streamside plant communities representing two opposite extremes of the gradient. The dominant families of the ridge group were Fagaceae, Illiciaceae, Theaceae, Aquifoliaceae and Lauraceae, whereas those dominating the streamside group were Rubiaceae, Araliceae, Lauraceae, Fagaceae, and Staphyleaceae. Most species had a patchy distribution and many were distributed randomly. Among those with a patchy distribution, Cyclobalanopsis championii and Rhododendron simsii only occurred on the ridge top, while Drypetes karapinensis and Ficus fistulosa occurred along the streamside. Illicium arborescens and Ilex cochinchinensis were commonly distributed on the intermediate slope. Species that appeared to be randomly or near-randomly distributed over the plot included Schefflera octophylla and Daphniphyllum glaucescens ssp. oldhamii. The distribution patterns of species also suggested that there was strong niche differentiation among species. It is found that the community of Nanjenshan forest is organized by different topographic plant associations. Maintenance of tree species diversity in the forests is largely due to differentiated environmental factors related to plot topography.

When the feature size keep shrinking to 4Xnm, ArF lithography has already proceed to immersion process and became mature enough. There is an important factor that will obviously influence photo process window in the initial phase development is the optical reflection from imperfect substrate design. From previous experience, reflection would be optimized to fine level by adjusting TARC (Top Anti-Reflection Coating) or BARC (Bottom Anti-Reflection Coating) thickness through index of reflectivity. However, actual criteria of reflectivity for various ArF lithography process are unlikely the same, e.g. different system type (wet/dry), node (feature size), illumination type, or even substrate effect, and also need to be examined to retain a decent process window. In this paper, experimental result of various abovementioned ArF process have been compared with reflectivity index from prolith simulation engine, and distinctly clarified criteria of reflectivity for each case. Furthermore, effects of reflection to several optics caused patterning-related results, e.g. IDB (Iso-Dense Bias), OPC (Optical Proximate Correction) accuracy, will also be discussed. The result also shows severe criterion of reflection is requested as feature size getting smaller to 4Xnm node, and RET-applied (Resolution Enhancement Technology) process has opposite result on it. From experimental results, IDB has been obviously affected by reflection and become one important factor that influences reflection criterion examination.

Spatial patterns of conspecific trees are considered as the consequences of biological interactions and environmental influences. They also reflect species interactions in plant communities. However, biological attributes are often neglected while deliberating the factors shaping species distributions. As rising attentions are paid to spatial patterns of tropical forest trees, we noticed that seven Center of Tropical Forest Sites and four Forest Dynamic Plots in Asia and America have presented analogously high proportions of species with aggregated conspecific individuals coincidently. This phenomenon is distinctive and repudiates fundamental ecology hypotheses which suggested dispersed distributions of conspecific tropical trees due to intensive density and natural enemy pressures in tropical forests. We believe that similar aggregation patterns shared by these tropical forests implies the existence of structuring forces in biogeographical scale instead of habitat heterogeneity in local community scales as scientists have considered. To approach the factors contributing to this cross-continent spatial pattern of trees, we obtained and reviewed ecosystem attributes, including topography, temperature, precipitation, biodiversity, density, and biomass, of these forests. Here we show that the proportions of aggregated species are actually constants independent of any ecosystem attributes regardless the nature of these tropical forests. However, local biodiversity are the major factor determining the number of aggregated species and the aggregation of large individuals of these forests. Aggregation of large trees declines along rising biodiversity, while the numbers of aggregated species increase permanently along lifting biodiversity. We propose a possible equilibrium and saturated status of the tropical forests in accommodating aggregated species. Furthermore, the tight correlations of biodiversity and species aggregation strongly imply the importance of overlooked biological interactions in shaping the spatial patterns in the tropical forests.