chyi-Rong Chiou - Academia.edu (original) (raw)

Papers by chyi-Rong Chiou

Diversity

In this study, the integration of useful statistical methods from different disciplines for analy... more In this study, the integration of useful statistical methods from different disciplines for analyzing the forest community of the Lienhuachih area of central Taiwan was attempted. We employed a seriated heat map to confirm the presence of multiple community patterns in the area and used the gap statistics and a clustplot to confirm the number and structure of the patterns, respectively. A minimum spanning tree was used to display a succession series among the quadrats, and Renyi diversity was used to indicate the species composition of these patterns. The results confirmed the existence of six patterns with different biodiversity structures in which pattern C was the succession prototype of the local community patterns. Next, we used the patterns as nodes of a social network to perform bipartite network analysis. The results showed that a community network consisted of 108 taxa and six syntaxa. The syntaxa were highly vulnerable to extinction; therefore, the optimal conservation str...

Wetland protected areas (WPA) are among the most productive natural environments providing substa... more Wetland protected areas (WPA) are among the most productive natural environments providing substantial socio-economic benefits to humans as well as habitat for numerous species. However, they are also highly vulnerable in the Anthropocene era due to various factors of population growth, unsustainable productions, climate change, etc. Assessing the land cover change of WPA and its driving force are necessary work for the sustainable development and management of WPA. Here, we investigated vegetation as an indicator for land cover changes in WPA because of its strong interaction with governance system and external related ecosystem of WPA, such as water resources, nutrient cycle, etc. Along with the change of vegetation, we examine how climate change contributes to WPA change and human management. With the complication of research tasks, social-ecological system (SES) approach was applied with three main elements: resource system (vegetation covers); external related ecosystems (clima...

In this study, we used solid-state 13C NMR spectroscopy, photometric analyses, and chemical fract... more In this study, we used solid-state 13C NMR spectroscopy, photometric analyses, and chemical fractionation to examine carbon (C) components and lability of SOM in a Japanese cedar (Cryptomeria japonica) forest and bamboo (Phyllostachys edulis) plantation reforested on a cutover primary broadleaf forest in Taiwan

物種分布模擬（Species Distribution Modeling，SDM）是利用物種分布點資料與環境預測圖層去量化物種－環境關係，其中，模擬物種分布之方法在近年來被大量地發展使用。本研究... more 物種分布模擬（Species Distribution Modeling，SDM）是利用物種分布點資料與環境預測圖層去量化物種－環境關係，其中，模擬物種分布之方法在近年來被大量地發展使用。本研究以臺灣水青岡為材料，應用7項環境預測變數，在BIOMOD2（BIOdiversity MODelling 2）平臺上同時完成10種模擬方法之分析，TSS、ROC、KAPPA指標評估結果顯示以GAM、RF、MAXENT方法模擬效果較佳，而FDA、SRE模擬效果較差，但實繪10種方法之預測機率圖，則發現不同方法所得之大致輪廓是相似的且符合現今臺灣水青岡之分布，同時為降低單一SDM方法的誤差，本文對預測較佳之模型進行整體模擬，藉由比較臺灣水青岡現今分布與潛在適合生育地之差異，有助於未來探討其與常綠闊葉樹之競爭、氣候變遷影響等問題。Species distribution modeling (SDM) is a numerical tool that combines species occurrence data with environmental predictor layers to explore speces-environment relationship. The SDM methods had greatly advanced in recent years. In this study, we use 10 SDM methods on BIOMOD2 platform to model the distribution of Fagus hayatae with 7 environmental variables. The results reveal that GAM, RF, and MAXENT gain the best performance, whereas FDA and SRE have the worst performance based on the TSS, ROC, and KAPPA evaluation. The general patterns of 10 SDM predictive maps are same and coincident with the current distribution of F. hayat...

Sustainability, 2021

Taiwan is highly dependent on imports of solid wood materials. In the past ten years (2009–2018),... more Taiwan is highly dependent on imports of solid wood materials. In the past ten years (2009–2018), it imported raw materials for solid wood products from 117 countries. Therefore, the diversity of raw material sources is a serious concern. The purpose of this research is to evaluate the risks of solid wood product supplies. The dispersion and concentration of supply sources are the measures. The SWI and HHI models are used to calculate the six major imported solid wood products. The results show that from the beginning of 2009 to the end of 2018, wood chips and pellets with the highest average annual import quantity had the lowest average performance in SWI and with the highest average HHI value, which indicates that wood chips and pellets are the riskiest items among the 6 solid wood products. While the sawn wood has the highest average SWI value and the lowest HHI value, it offers the smallest supply risk.

Abies kawakamii forests are generally distributed above 3,000 m in Taiwanese high mountains. The ... more Abies kawakamii forests are generally distributed above 3,000 m in Taiwanese high mountains. The community data used in our analysis were derived from the database of the National Vegetation Diversity Inventory and Mapping Project of Taiwan (NVDIMP), and environmental data were obtained from the WorldClim and NVDIMP databases. We used non-metric multidimensional scaling (NMDS) to identify vegetation composition of Abies communities and the structural equation models (SEMs) were used to examine the complex relationships between environmental factors and vegetation composition. The results of ordination showed the most important factors determining species composition of Abies forests involved habitat rockiness, heat load index, warmth index and summer and winter. SEM results approved the warmth index and winter precipitation were the main drivers determining the latent variable-climate, which significantly affect the overstory composition of Abies communities. The relative frequency ...

Taiwan Journal of Forest Science, 2009

This article describes the successful implementation and preliminary results of the first nationa... more This article describes the successful implementation and preliminary results of the first national vegetation inventory in Taiwan. This project which aimed to establish national criteria for vegetation classification, map island-wide forest vegetation at a scale of 1: 5000 and establish a vegetation data management system was launched in 2003. More than 3000 permanent plots (20 m×20 m) were set up throughout Taiwan, and 792 articles on vegetation of Taiwan were located to acquire vegetation data. Vegetation types were identified according to the physiognomic appearances in aerial photographs. The national vegetation classification system was constructed by referring to field observations, vegetation data, and currently available vegetation classification schemes. This project was finalized in 2008. Up to 67% of native vascular plant species in Taiwan were recorded, and 59% of the total area of Taiwan was mapped in this project. Preliminary vegetation analyses identified 9 major vege...

Forests, 2021

Forest is the largest ecosystem in the land area of Taiwan. In the past, most of the studies on t... more Forest is the largest ecosystem in the land area of Taiwan. In the past, most of the studies on the evaluation of forest ecosystem services were regional, and therefore lacked national assessment. This study uses a market value method and a benefit transfer method to assess the value of the forest ecosystem services in Taiwan, and expounds the link between ecosystem services and the effectiveness of forestry management and conservation. Preliminarily, it is estimated that the total value of forest ecosystem services in 2016 was approximately NT $749,278 million (equal to approximately 47.6 billion U.S. dollars, PPP-corrected), accounting for 4.28% of the GDP in 2016. The quotation of unit price data has a huge impact on the final assessment results of forest ecosystem service value, and therefore it is necessary use it appropriately.

Sustainability, 2021

Urban trees could provide a variety of ecosystem services. However, they require conservation to ... more Urban trees could provide a variety of ecosystem services. However, they require conservation to sustain a healthy and consistent provision of services. This study applies an extended theory of planned behavior (ETPB) to understand residents’ pay intention for conserving urban trees. In order to explore the impact of the public perception of urban trees, two constructs such as perceived usefulness and perceived tree benefits have been added to the TPB model. This study conducted a questionnaire survey on Taipei city residents and received 364 valid responses. The partial least squares structural equation modeling (PLS-SEM) was used for the analysis of the model. The results show that residents’ perceived usefulness and perceived tree benefits of urban trees have a significantly positive impact on public attitude toward protecting urban trees. Individuals’ intention to pay towards conservation of urban trees is, on the other hand, affected by subjective norm, attitude, perceived beha...

Remote sensing data and automated image analysis techniques are powerful tools to consistently an... more Remote sensing data and automated image analysis techniques are powerful tools to consistently and repeatedly identify and evaluate land cover types over large areas. Landsat TM data can provide important spectral and time specific information about ground cover types. Generally speaking, the classification accuracy of Landsat TM data for level Ⅲ in mountainous terrain is relatively low. Therefore, the purpose of this study was to develop an effective method to integrate spectral and ancillary information in order to improve the classification performance in areas of mountainous terrain. A fuzzy multicriteria decision process was developed to integrate spectral and elevation information for classifying Landsat TM data of the Rocky Mountain National Park. Five classification algorithms were compared in this study. The results indicate that a 2-stage approach which uses the minimum-distance to means to determine the 5 most possible candidates and the fuzzy multicriteria decision proce...

With the rapid rate of urbanization and increasing demands for forest resources, the vegetation c... more With the rapid rate of urbanization and increasing demands for forest resources, the vegetation cover has also decreased at a proportional rate in Taiwan. Government agencies and forest managers have come to realize the importance of the ecosystem and begun to implement conservation practices. Prediction of vegetation distribution will be a primary step in this effort. In this study, we developed logistic regression models for predicting the distribution of Abies kawakamii (Taiwan fir). Tsuga chinensis var. formnosana (Taiwan hemlock), and Chamaecyparis spp. (Taiwan cypress). The models achieved high R^2 and receiver operating characteristic (ROC) values. Overlaying the probability of map of Taiwan cypress and Taiwan fir showed a transition boundary for two species occurring at an elevation of approximately 2700 m. The distribution model showed an oval species distribution pattern, narrower and lower at north and south, and higher and wider in the middle. Therefore, the Massenerhebu...

Among the intricate network of physical environmental factors, solar radiation constitutes the ma... more Among the intricate network of physical environmental factors, solar radiation constitutes the main source of energy for all ecological systems. It is not only the effective variant in ecological and environmental studies, but also the influencing mechanism behind the entire ecosystem energy, nutrient cycles and food chains. As such, the control of the spatial variation of solar radiation thus becomes the focus of most ecosystem studies. This study used the precision Spectral Pyranometer (PSP) to calibrate our self-designed devices. Then, these self-designed devices were observed at Mount Ling-jih and He-she river valley to validate the skylight radiation model and the terrestrial reflected radiation model. Results showed that under the hypothesis of isotropy, the estimation of skylight radiation through skyview factor, and the estimation of terrestrial reflected radiation based on the modified Dozier model are both applicable to forest areas.

Journal of Forest Research, 2021

Forests, 2020

Accurately quantifying the size–density relationships is important to predict stand development, ... more Accurately quantifying the size–density relationships is important to predict stand development, estimate stand carrying capacity and prescribe silvicultural treatments. Parametric methods, such as segmented regression, were proposed to estimate the complicated trajectory of size–density relationships. However, applying nonparametric methods to assess stand development has not been explicitly examined. In this study, we compared parametric and nonparametric methods for estimating size–density relationships for Japanese cedar plantations in Taiwan. Specifically, we compared the efficacy of two segmented regression models with the penalized spline and random forest for regression methods. We also examined various stages in stand development for old-growth Japanese cedar stands. Data collected from 237 Japanese cedar permanent plots were used in model fitting and validation. Results indicated that the parametric and nonparametric methods used in this study can provide reliable estimate...

Journal of Geophysical Research: Biogeosciences, 2019

Forests, 2019

Forest thinning is a way to make room for the growth of remaining trees, and the thinned wood can... more Forest thinning is a way to make room for the growth of remaining trees, and the thinned wood can serve as a fuel for bioenergy in order to combat climate change. Using thinned wood for bioenergy can substitute for fossil fuel energy, resulting in potential carbon benefit. Since not all thinned wood can be transported out of the forest for processing, the extraction ratio (extraction volume/thinning volume) is an important variable for determining the net carbon benefit. This study investigated 52 forest-thinning sites in Taiwan. The extraction ratio was estimated to explore the benefit of thinned wood used as bioenergy. Cross analysis was adopted to find the relationships between site/species attributes and extraction ratio. The factors included age class, thinning method, land use classification, and species. Key variables included thinning volume, extraction volume, and extraction ratio. Statistical analysis was then applied to identify the significant differences. The analysis s...

PloS one, 2016

Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) alon... more Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) along an elevation gradient is important for understanding the response of SOM to global warming. We evaluated the composition of SOM and structure of humic acids along an altitudinal gradient from 600 to 1400 m in moso bamboo (Phyllostachys edulis) plantations in central Taiwan using NMR spectroscopy and photometric analysis. Total organic C and total nitrogen (N) content increased with increasing elevation. Aromaticity decreased and ΔlogK (the logarithm of the absorbance ratio of humic acids at 400 and 600 nm) increased with increasing elevation, which suggests that SOM humification decreased with increasing elevation. High temperature at low elevations seemed to enhance the decomposition (less accumulation of total organic C and N) and humification (high aromaticity and low ΔlogK). The alkyl-C/O-alkyl-C (A/O-A) ratio of humic acids increased with increasing elevation, which suggests that ...

Diversity

In this study, the integration of useful statistical methods from different disciplines for analy... more In this study, the integration of useful statistical methods from different disciplines for analyzing the forest community of the Lienhuachih area of central Taiwan was attempted. We employed a seriated heat map to confirm the presence of multiple community patterns in the area and used the gap statistics and a clustplot to confirm the number and structure of the patterns, respectively. A minimum spanning tree was used to display a succession series among the quadrats, and Renyi diversity was used to indicate the species composition of these patterns. The results confirmed the existence of six patterns with different biodiversity structures in which pattern C was the succession prototype of the local community patterns. Next, we used the patterns as nodes of a social network to perform bipartite network analysis. The results showed that a community network consisted of 108 taxa and six syntaxa. The syntaxa were highly vulnerable to extinction; therefore, the optimal conservation str...

Wetland protected areas (WPA) are among the most productive natural environments providing substa... more Wetland protected areas (WPA) are among the most productive natural environments providing substantial socio-economic benefits to humans as well as habitat for numerous species. However, they are also highly vulnerable in the Anthropocene era due to various factors of population growth, unsustainable productions, climate change, etc. Assessing the land cover change of WPA and its driving force are necessary work for the sustainable development and management of WPA. Here, we investigated vegetation as an indicator for land cover changes in WPA because of its strong interaction with governance system and external related ecosystem of WPA, such as water resources, nutrient cycle, etc. Along with the change of vegetation, we examine how climate change contributes to WPA change and human management. With the complication of research tasks, social-ecological system (SES) approach was applied with three main elements: resource system (vegetation covers); external related ecosystems (clima...

In this study, we used solid-state 13C NMR spectroscopy, photometric analyses, and chemical fract... more In this study, we used solid-state 13C NMR spectroscopy, photometric analyses, and chemical fractionation to examine carbon (C) components and lability of SOM in a Japanese cedar (Cryptomeria japonica) forest and bamboo (Phyllostachys edulis) plantation reforested on a cutover primary broadleaf forest in Taiwan

物種分布模擬（Species Distribution Modeling，SDM）是利用物種分布點資料與環境預測圖層去量化物種－環境關係，其中，模擬物種分布之方法在近年來被大量地發展使用。本研究... more 物種分布模擬（Species Distribution Modeling，SDM）是利用物種分布點資料與環境預測圖層去量化物種－環境關係，其中，模擬物種分布之方法在近年來被大量地發展使用。本研究以臺灣水青岡為材料，應用7項環境預測變數，在BIOMOD2（BIOdiversity MODelling 2）平臺上同時完成10種模擬方法之分析，TSS、ROC、KAPPA指標評估結果顯示以GAM、RF、MAXENT方法模擬效果較佳，而FDA、SRE模擬效果較差，但實繪10種方法之預測機率圖，則發現不同方法所得之大致輪廓是相似的且符合現今臺灣水青岡之分布，同時為降低單一SDM方法的誤差，本文對預測較佳之模型進行整體模擬，藉由比較臺灣水青岡現今分布與潛在適合生育地之差異，有助於未來探討其與常綠闊葉樹之競爭、氣候變遷影響等問題。Species distribution modeling (SDM) is a numerical tool that combines species occurrence data with environmental predictor layers to explore speces-environment relationship. The SDM methods had greatly advanced in recent years. In this study, we use 10 SDM methods on BIOMOD2 platform to model the distribution of Fagus hayatae with 7 environmental variables. The results reveal that GAM, RF, and MAXENT gain the best performance, whereas FDA and SRE have the worst performance based on the TSS, ROC, and KAPPA evaluation. The general patterns of 10 SDM predictive maps are same and coincident with the current distribution of F. hayat...

Sustainability, 2021

Taiwan is highly dependent on imports of solid wood materials. In the past ten years (2009–2018),... more Taiwan is highly dependent on imports of solid wood materials. In the past ten years (2009–2018), it imported raw materials for solid wood products from 117 countries. Therefore, the diversity of raw material sources is a serious concern. The purpose of this research is to evaluate the risks of solid wood product supplies. The dispersion and concentration of supply sources are the measures. The SWI and HHI models are used to calculate the six major imported solid wood products. The results show that from the beginning of 2009 to the end of 2018, wood chips and pellets with the highest average annual import quantity had the lowest average performance in SWI and with the highest average HHI value, which indicates that wood chips and pellets are the riskiest items among the 6 solid wood products. While the sawn wood has the highest average SWI value and the lowest HHI value, it offers the smallest supply risk.

Abies kawakamii forests are generally distributed above 3,000 m in Taiwanese high mountains. The ... more Abies kawakamii forests are generally distributed above 3,000 m in Taiwanese high mountains. The community data used in our analysis were derived from the database of the National Vegetation Diversity Inventory and Mapping Project of Taiwan (NVDIMP), and environmental data were obtained from the WorldClim and NVDIMP databases. We used non-metric multidimensional scaling (NMDS) to identify vegetation composition of Abies communities and the structural equation models (SEMs) were used to examine the complex relationships between environmental factors and vegetation composition. The results of ordination showed the most important factors determining species composition of Abies forests involved habitat rockiness, heat load index, warmth index and summer and winter. SEM results approved the warmth index and winter precipitation were the main drivers determining the latent variable-climate, which significantly affect the overstory composition of Abies communities. The relative frequency ...

Taiwan Journal of Forest Science, 2009

This article describes the successful implementation and preliminary results of the first nationa... more This article describes the successful implementation and preliminary results of the first national vegetation inventory in Taiwan. This project which aimed to establish national criteria for vegetation classification, map island-wide forest vegetation at a scale of 1: 5000 and establish a vegetation data management system was launched in 2003. More than 3000 permanent plots (20 m×20 m) were set up throughout Taiwan, and 792 articles on vegetation of Taiwan were located to acquire vegetation data. Vegetation types were identified according to the physiognomic appearances in aerial photographs. The national vegetation classification system was constructed by referring to field observations, vegetation data, and currently available vegetation classification schemes. This project was finalized in 2008. Up to 67% of native vascular plant species in Taiwan were recorded, and 59% of the total area of Taiwan was mapped in this project. Preliminary vegetation analyses identified 9 major vege...

Forests, 2021

Forest is the largest ecosystem in the land area of Taiwan. In the past, most of the studies on t... more Forest is the largest ecosystem in the land area of Taiwan. In the past, most of the studies on the evaluation of forest ecosystem services were regional, and therefore lacked national assessment. This study uses a market value method and a benefit transfer method to assess the value of the forest ecosystem services in Taiwan, and expounds the link between ecosystem services and the effectiveness of forestry management and conservation. Preliminarily, it is estimated that the total value of forest ecosystem services in 2016 was approximately NT $749,278 million (equal to approximately 47.6 billion U.S. dollars, PPP-corrected), accounting for 4.28% of the GDP in 2016. The quotation of unit price data has a huge impact on the final assessment results of forest ecosystem service value, and therefore it is necessary use it appropriately.

Sustainability, 2021

Urban trees could provide a variety of ecosystem services. However, they require conservation to ... more Urban trees could provide a variety of ecosystem services. However, they require conservation to sustain a healthy and consistent provision of services. This study applies an extended theory of planned behavior (ETPB) to understand residents’ pay intention for conserving urban trees. In order to explore the impact of the public perception of urban trees, two constructs such as perceived usefulness and perceived tree benefits have been added to the TPB model. This study conducted a questionnaire survey on Taipei city residents and received 364 valid responses. The partial least squares structural equation modeling (PLS-SEM) was used for the analysis of the model. The results show that residents’ perceived usefulness and perceived tree benefits of urban trees have a significantly positive impact on public attitude toward protecting urban trees. Individuals’ intention to pay towards conservation of urban trees is, on the other hand, affected by subjective norm, attitude, perceived beha...

Remote sensing data and automated image analysis techniques are powerful tools to consistently an... more Remote sensing data and automated image analysis techniques are powerful tools to consistently and repeatedly identify and evaluate land cover types over large areas. Landsat TM data can provide important spectral and time specific information about ground cover types. Generally speaking, the classification accuracy of Landsat TM data for level Ⅲ in mountainous terrain is relatively low. Therefore, the purpose of this study was to develop an effective method to integrate spectral and ancillary information in order to improve the classification performance in areas of mountainous terrain. A fuzzy multicriteria decision process was developed to integrate spectral and elevation information for classifying Landsat TM data of the Rocky Mountain National Park. Five classification algorithms were compared in this study. The results indicate that a 2-stage approach which uses the minimum-distance to means to determine the 5 most possible candidates and the fuzzy multicriteria decision proce...

With the rapid rate of urbanization and increasing demands for forest resources, the vegetation c... more With the rapid rate of urbanization and increasing demands for forest resources, the vegetation cover has also decreased at a proportional rate in Taiwan. Government agencies and forest managers have come to realize the importance of the ecosystem and begun to implement conservation practices. Prediction of vegetation distribution will be a primary step in this effort. In this study, we developed logistic regression models for predicting the distribution of Abies kawakamii (Taiwan fir). Tsuga chinensis var. formnosana (Taiwan hemlock), and Chamaecyparis spp. (Taiwan cypress). The models achieved high R^2 and receiver operating characteristic (ROC) values. Overlaying the probability of map of Taiwan cypress and Taiwan fir showed a transition boundary for two species occurring at an elevation of approximately 2700 m. The distribution model showed an oval species distribution pattern, narrower and lower at north and south, and higher and wider in the middle. Therefore, the Massenerhebu...

Among the intricate network of physical environmental factors, solar radiation constitutes the ma... more Among the intricate network of physical environmental factors, solar radiation constitutes the main source of energy for all ecological systems. It is not only the effective variant in ecological and environmental studies, but also the influencing mechanism behind the entire ecosystem energy, nutrient cycles and food chains. As such, the control of the spatial variation of solar radiation thus becomes the focus of most ecosystem studies. This study used the precision Spectral Pyranometer (PSP) to calibrate our self-designed devices. Then, these self-designed devices were observed at Mount Ling-jih and He-she river valley to validate the skylight radiation model and the terrestrial reflected radiation model. Results showed that under the hypothesis of isotropy, the estimation of skylight radiation through skyview factor, and the estimation of terrestrial reflected radiation based on the modified Dozier model are both applicable to forest areas.

Journal of Forest Research, 2021

Forests, 2020

Accurately quantifying the size–density relationships is important to predict stand development, ... more Accurately quantifying the size–density relationships is important to predict stand development, estimate stand carrying capacity and prescribe silvicultural treatments. Parametric methods, such as segmented regression, were proposed to estimate the complicated trajectory of size–density relationships. However, applying nonparametric methods to assess stand development has not been explicitly examined. In this study, we compared parametric and nonparametric methods for estimating size–density relationships for Japanese cedar plantations in Taiwan. Specifically, we compared the efficacy of two segmented regression models with the penalized spline and random forest for regression methods. We also examined various stages in stand development for old-growth Japanese cedar stands. Data collected from 237 Japanese cedar permanent plots were used in model fitting and validation. Results indicated that the parametric and nonparametric methods used in this study can provide reliable estimate...

Journal of Geophysical Research: Biogeosciences, 2019

Forests, 2019

Forest thinning is a way to make room for the growth of remaining trees, and the thinned wood can... more Forest thinning is a way to make room for the growth of remaining trees, and the thinned wood can serve as a fuel for bioenergy in order to combat climate change. Using thinned wood for bioenergy can substitute for fossil fuel energy, resulting in potential carbon benefit. Since not all thinned wood can be transported out of the forest for processing, the extraction ratio (extraction volume/thinning volume) is an important variable for determining the net carbon benefit. This study investigated 52 forest-thinning sites in Taiwan. The extraction ratio was estimated to explore the benefit of thinned wood used as bioenergy. Cross analysis was adopted to find the relationships between site/species attributes and extraction ratio. The factors included age class, thinning method, land use classification, and species. Key variables included thinning volume, extraction volume, and extraction ratio. Statistical analysis was then applied to identify the significant differences. The analysis s...

PloS one, 2016

Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) alon... more Studying the influence of climatic and/or site-specific factors on soil organic matter (SOM) along an elevation gradient is important for understanding the response of SOM to global warming. We evaluated the composition of SOM and structure of humic acids along an altitudinal gradient from 600 to 1400 m in moso bamboo (Phyllostachys edulis) plantations in central Taiwan using NMR spectroscopy and photometric analysis. Total organic C and total nitrogen (N) content increased with increasing elevation. Aromaticity decreased and ΔlogK (the logarithm of the absorbance ratio of humic acids at 400 and 600 nm) increased with increasing elevation, which suggests that SOM humification decreased with increasing elevation. High temperature at low elevations seemed to enhance the decomposition (less accumulation of total organic C and N) and humification (high aromaticity and low ΔlogK). The alkyl-C/O-alkyl-C (A/O-A) ratio of humic acids increased with increasing elevation, which suggests that ...