Chengyang Xu

• PhD
• Associate Professor (Full) at Jilin Academy of Forest Science

The Leaf Area Index (LAI) is a critical parameter that sheds light on the composition and function of forest ecosystems. Its efficient and rapid measurement is essential for simulating and estimating ecological activities such as vegetation productivity, water cycle, and carbon balance. In this study, we propose to combine high-resolution GF-6 2 m...

Air pollution poses a significant threat to public health, while biogenic volatile organic compounds (BVOCs) play a crucial role in both aspects. However, the unclear relationship between BVOCs and air pollutants in the under-canopy space limits the accuracy of air pollution control and the exploitation of forest healthcare functions. To clarify th...

Despite growing recognition of nature-based solutions (NBS), there remains a research gap in understanding their implementation in urban areas, which poses a significant challenge for urban forest development. Therefore, our paper aims to explore the intersection of NBS with urban forests (UF), identify current barriers, propose strategies to maxim...

Dioecious plants are often used in landscaping because of sex differences in individual appearance, resistance and ornamental value. Although a large number of studies have investigated the overall differences in resource allocation between different sexes in dioecious plants, the effects of environmental factors such as temperature and precipitati...

Chlorophyll (Chl) fluorescence induction (FI) upon a dark–light transition has been widely analyzed to derive information on initial events of energy conversion and electron transfer in photosystem II (PSII). However, currently, there is no analytical solution to the differential equation of QA reduction kinetics, raising a doubt about the fitting...

Urban green space promotes the health of urban residents, enhances urban ecosystem biodiversity, mitigates environmental pollution, and attenuates urban heat island effect. However, urban vegetation cover is highly heterogeneous and difficult to quantify. In this study, the variation of urban fractional vegetation cover (FVC) in 328 cities in China...

Despite inter-specific differences in hydraulic traits at broad scale have been comprehensively studied, intra- specific hydraulic variability in situ is less well known. Which hydraulic traits can better predict whole-plant performance in field both within and across species remains largely ambiguous. In the study, we conducted a field investigati...

Background and aims: The photoprotective role of foliar anthocyanins has long been ambiguous: exacerbating, being indifferent to, or ameliorating the photoinhibition of photosynthesis. The photoinhibitory light spectrum, failure to separate photo-resistance from repair, as well as the different methods used to quantify the photo-susceptibility of...

The past century has seen dramatic increases in global temperatures and mounting urbanization. As a result of these events, the urban heat island (UHI) effect has received growing attention in scientific research worldwide. A global search was initially conducted using a scientific literature database to collect all available relevant publications...

The COVID-19 pandemic created unprecedented challenges for people’s health. Studies have demonstrated the positive impact of urban green spaces, particularly urban parks, on physical and mental health. However, few studies have evaluated social health, which is a component of human health, and more understanding of the relationship between urban pa...

Tree thinning affects the light environment, which in turn affects the growth and survival of understory vegetation, thus improving species diversity and nutrient cycling, as well as the ecological habitat factors. However, the response of understory vegetation to the thinning intensity and short-time effects in the temperate broadleaf-conifer mixe...

Differences in the accessibility to urban resources between different racial and socioeconomic groups have exerted pressure on effective planning and management for sustainable city development. However, few studies have examined the multiple factors that may influence the mitigation of urban green spaces (UGS) inequity. This study reports the resu...

Urban parks provide multiple ecosystem services as an important element of the urban space and improve human health and wellbeing. This study used the Gaussian-based 2SFCA method to evaluate the spatiotemporal distribution of and changes in park accessibility within the Sixth Ring Road in Beijing over 15 years. The study also used bivariate correla...

Background Understanding the ecological strategies of urban trees to the urban environment is crucial to the selection and management of urban trees. However, it is still unclear whether urban tree pit cover will affect plant functional traits. Here, we study the response of urban trees to different tree pit covers, analyzed the effects of differen...

Background How to quickly predict and evaluate urban dust deposition is the key to the control of urban atmospheric environment. Here, we focus on changes of plant reflectance and plant functional traits due to dust deposition, and develop a prediction model of dust deposition based on these traits. Results The results showed that (1) The average...

As human living environments face increasing challenges with resilience, the concept of nature-based solutions (NBS) was proposed in recent years as a way to promote sustainable living in urban environments. Urban forests and trees play important roles in urban ecosystems, while their potential as an NBS is promising. A bibliometric analysis was fi...

Background Functional trait-based ecological research has been instrumental in advancing our understanding of environmental changes. It is still, however, unclear how the functional traits of urban plants respond to atmospheric particulate matter, and which trade-off strategies are shown. In order to explore the variation of plant functional traits...

Biogenic volatile organic compound (BVOC) is an important part of forest healthcare effect, while it has not received enough attention in urban greenspace construction. Consequently, the aim of this study was to analyze BVOC emission rates and compositions released from leaves and flowers of landscape species in urban greenspace and to make suggest...

Background: The visual forms of individual trees in peri-urban forests are driven by a complex array of simultaneous cause-and-effect relationships. Materials and Methods: Structural Equation Modeling (SEM), as a specialized analytical technique, was used to model and understand the complex interactions. It was applied to find out responses of visu...

Colletotrichum gloeosporioides is one of the most common and serious fungal diseases of the tree Mangifera persiciforma. Yet we lack an effective method to evaluate this ecological interaction accurately. Here, we measured the functional traits and leaf reflectance spectrum of the host plants under different disease degrees. The findings provide a...

Understanding human perceptions and quantifying parameters that characterize landscape visual quality in an urban green space is important to describe these connections. Within this environment, the association between human perceptions of landscape visual quality (LVQ) have long been of interest to a wide variety of fields. Previous studies have r...

While efforts to standardize urban forest inventory data have occurred, the information collected from community to community remains quite variable. In this study, we conducted a global review of peer-reviewed and published research that collected tree inventory data to assess what information is being collected. In addition to this review, we als...

Background: Functional trait-based ecological research has been instrumental in advancing our understanding of understanding of environmental changes. It is still, however, unclear how the functional traits of urban plants respond to atmospheric particulate pollution, and what trade-off strategies are shown. In order to explore the variation of pla...

Studies on the influence of parasitism on plants based on hyperspectral analysis have not been reported so far. To fully understand the variation characteristics and laws of leaf reflectance spectrum and functional traits after the urban plant parasitized by Cuscuta japonica Choisy. Osmanthus fragrans (Thunb.) Lour. was taken as the research object...

Background: Studies on the influence of parasitism on plants based on hyperspectral analysis have not been reported so far. To fully understand the variation characteristics and laws of leaf reflectance spectrum and functional traits after the urban plant parasitized by Cuscuta japonica Choisy. Osmanthus fragrans (Thunb.) Lour. was taken as the res...

Urban green space is an important element of well-being. It is still, however, lacking of research on green space demand analyzing based on social platform data. This research uses social platform data to evaluate people's demand for urban green space under the background of the global COVID-19 pneumonia. Using the micro-blog database of geographic...

To quantitatively reflect the relationship between dust and plant spectral reflectance. Dust from different sources in the city were selected to simulate the spectral characteristics of leaf dust. Taking Euonymus japonicus as the research object. Prediction model of leaf dust deposition was established based on spectral parameters. Results showed t...

Nocturnal sap flow is an important part of plant sap flow, while it is usually regarded as negligible. Consequently, the aim of this study was to measure nocturnal stem sap flow of Acer truncatum and to determine its driving force in an urban green space. Stomatal aperture was measured using surface impression method in a typical clear day of Augus...

Integrating tree species diversity into urban forest management can help create resilient tree populations. In this study, the abundance of trees within families, genera, and species levels was determined through a system developed to evaluate the diversity of urban street trees at different scales. Municipal foresters were asked to report the six...

Quercus aquifolioides is one of the most representative broad-leaved plants in Qinghai-Tibet Plateau with important ecological status. So far, understanding how to quickly estimate the chlorophyll content of plants in plateau areas is still an urgent problem. Field Spec 3 spectrometer was used to measure hyperspectral reflectance data of Quercus aq...

Rapidly determining leaf vein network patterns and vein densities is biologically important and technically challenging. Current methods, however, are limited to vein contour extraction. Further image processing is difficult, and some leaf vein traits of interest therefore cannot be quantified. In this study, we proposed a novel method for the fast...

Abstract Background Response and adaptation strategies of plants to the environment have always been the core issues in ecological research. So far, relatively little study exists on its functional traits responses to warming, especially in an urban environment. This information is the key to help understand plant responses and trade-off strategy t...

Landscape color provides visual attractiveness and is an important landscape architecture construct in design and with aesthetics. Along roadways, plant color in a midground position provides a potential location readily seen by people. However, few studies have quantitatively explored the impact of a green (original) only compared to additions of...

Integrating tree species diversity into urban forest management can help create resilient tree populations. In this study, the abundance of trees within families, genera, and species levels was determined through a system developed to evaluate the diversity of urban street trees at different scales. Municipal foresters were asked to report the six...

Urban plants can improve several environmental pollution problems in cities, especially dust prevention, noise reduction, purification of the atmosphere, etc. To explore the influence of dust deposition on the spectral characteristics of the leaf, a foliar dust deposition prediction model based on high-spectrum data was established. Taking Euonymus...

The extraction of leaf network and the measurement of its trait parameters provide an important reference for the study of leaf vein ecology. Taking the leaves of six tree species (Sophora japonica, Populus tomentosa, Ailanthus altissima, Fraxinus pennsylvanica, Acer truncutum and Koelreuteria paniculata) with different leaf characteristics as obje...

【Objective】 This research aims at investigating the variation patterns of tree morphology with different stand densities and mingling intensities in natural scenic forest, and clarifying the effects of stand density, mingling intensity and their interaction on tree morphology of different diameter classes. 【Method】65 plots were set up in typical ar...

The object was to study the response of plant leaf traits and their related relationships to the thermal environment effect of urban underlying surface and its ecological trade-off strategy. Results showed that specific leaf area, chlorophyll content, stomatal area, stomatal aperture and leaf nitrogen-phosphorus ratio were all increased firstly and...

Understanding the relationships between twig and leaf traits provides valuable insights into the adaptive strategies of plant species. There are limited studies addressing the shade tolerance of woody species regarding trade-offs between twig and leaf traits. However, there are two contrasting hypotheses regarding the characteristics of shade toler...

Leaf stomata are important structures used for exchanging matter between plants and the environment, and they are very sensitive to environmental changes. The method of efficiently extracting stomata, as well as measuring stomatal density and area, still lacks established techniques. This study focused on the leaves of Fraxinus pennsylvanica Marsha...

[Objective] Exploring variations of plant functional traits and leaf economics spectrum along urban thermal environment provides a chemical basis for examining species strategies as shaped by their local habitat. [Method] In this study, we quantified the land surface temperature, soil moisture content and leaf functional traits of Sophora japonica,...

[Objective]Leaf stomatal is a main channel used as exchange matter between plants and environment, which is very sensitive to environmental changes. How to calculate stomatal area and openness data quickly and accurately still lacks mature methods and techniques. This paper aims to explore the quantitative calculation of leaf stomatal density and s...

The relationship between scenic beauty grade and measured tree indicators was studied through evaluation of 427 photos of individual Pinus tabulaeformis trees by using the scenic beauty estimation (SBE) method. Thirteen indices to reflect trunk, crown and stem-to-canopy ratios of individual trees were evaluated by invited students. Results showed t...

The city of Beijing began its “country parks circle projects” in 2007; since then, more than 50 country parks have been built to provide recreational facilities and to improve the quality of the landscape surrounding the city. As this fast-paced and massive construction of country parks has been put into public use, many problems that are associate...

The public’s demand for more and better forest landscapes is increasing as scenic forest tours flourish in China, especially in the capital, Beijing. How to improve the quality of scenic forests has become one of the greatest concerns of urban foresters. Although numerous studies have focused on scenic forest management, to date, no reports have be...

【Objective】This research was carried out to investigate the short-term responses and regular patterns of leaf gas exchange characteristics of Cotinus coggygria seedlings，collected from different locations，to soil water stress． 【Method】A field experiment was set and the one-year-old C． coggygria seedlings were collected from three locations: Xishan...

Bamboos constitute a very important and versatile resource worldwide. A lot of Asian, African and South American people rely on bamboo products for their housing and farming tools. Meanwhile, the shoots of these plants are regarded as vegetables in East and South-East Asian nations. China has the greatest bamboo forest area (extension) and the larg...

Bamboos constitute a very important and versatile resource worldwide. A lot of Asian, African and South American people rely on bamboo products for their housing and farming tools. Meanwhile, the shoots of these plants are regarded as vegetables in East and South-East Asian nations. China has the greatest bamboo forest area (extension) and the larg...

Bamboos constitute a very important and versatile resource worldwide. A lot of Asian, African and South American people rely on bamboo products for their housing and farming tools. Meanwhile, the shoots of these plants are regarded as vegetables in East and South-East Asian nations. China has the greatest bamboo forest area (extension) and the larg...

The photosynthetic characteristics of Abies holophylla seedlings from six provenances under four artificial light intensities in a greenhouse (full light, 75.08%, 55.42%, and 30.38% of full light) were studied to explore the underlying genetic differences in foliar photosynthesis. Varying light intensities significantly affected the foliar photosyn...

Rising urbanization and the human population is taking its toll on the availability of urban greenspaces in cities. To provide places for people to enjoy outdoor recreation and experience nature, the city of Beijing started its massive “country park circle” project located between the fourth and fi fth Ring Roads in 2007. To further understand the...

It is not clear about the interactive effects of nitrogen, phosphorus, and potassium additions on carbohydrate accumulation in tree seedlings in the late-season of fall. In late September of 2009, 0 or 60 kg nitrogen ha−1 urea (46-0-0) was applied with 30 and 60 kg phosphorus ha−1 potassium hydrogen phosphate (0-41-45) to transplanted bareroot Chan...

Urban areas are key sources of reactive atmospheric nitrogen (N). Urban forests are moving towards a state of “N-saturation” due to N-deposition. However, the possible future-trend of inherent N-cycling in trees in response to urbanization-related Ndeposition is not well known. With regard to the contradiction of current studies on the exogenous N-...

Tree grading is one of important foundation works in thinning of young- and middle-age stands，however tree grading techniques for scenic forests are not reported． In this study，554 individual trees in 13 different stands of Pinus tabulaeformis scenic plantation in Xishan Forest Farm of Beijing Municipal Bureau of Landscape and Forestry were targete...

Ｒemote sensing is a key technology used in landscape quality assessment of scenic forests． This paper described the significance of landscape quality assessment and development process of landscape quality assessment of scenic forests． Applications of remote sensing in landscape pattern and dynamic，visualization and computerized management of sceni...

During the early time after transplanting, the ability of nitrogen (N) uptake in roots of tree stocks is crucial to their future performance. However, it is not clear about the relationship between size or nutrient reserves in nursery-cultured tree seedlings and root N flux (N flow within or out of root) after transplanting. In this study, we pre-f...

Traditional nursery culture of Changbai larch (Larix olgensis Henry) in Northeast China requires up to a 2-year nursery production period. The high cost of seedling culture for this duration has been identified as a constraint. As a potential means to help to shorten the cultural period, we evaluated growth, biomass accumulation, and nitrogen (N) u...

The response of poplar to nitrogen (N) fertilizer application varies with clones. Our objective was to quantify differences in resource allocation in two hybrid poplar clones due to nitrogen conditions. A two clone (46 and 107)-by-three nitrogen conditions (poor, medium and rich) factorial randomized design was replicated three times and undertaken...

The effect of supply ratio of nitrogen (N): phosphorus (P) on P uptake and utilization in germinated Changbai larch (Larix olgensis Henry.) was analyzed in our research. The seedlings were cultivated in a greenhouse where fertilizers were supplied according to N:P ratios of 1:3, 1:2, 1:1, 2:1 and 3:1. Seedling morphology and biomass accumulation, P...

There are four types of typical vegetable configurations， including conifer-broadleaved-herb species community，conifer-shrub-herb species community，broadleaved-shrub-herb species community and shrub-herb species community，as well as the mixed Pinus tabulaeformis forest and mixed Salix matsudana f． pendula forest in the urban forests in Beijing． The...

Bareroot Changbai larch (Larix olgensis Henry.) seedlings were reared with inorganic fertilizer (nitrogen (N):phosphorus (P)=1:1, W/W) applied at a rate of 100 (F100) or 200kgNha−1 (F200) with (+) or without (−) chicken manure as a soil amendment (O) in north-eastern China. An unfertilized control treatment was included. Inorganic and organic ferti...

We quantified biomass accumulation and nitrogen (N) retranslocation, allocation, and utilization of Changbai larch (Larix olgensis) seedlings subjected to four fertilization treatments (24, 59, 81, 117 kg·ha−1 N) with an unfertilized control during summer and autumn 2009. Ammonium phosphate (18-46-0) was the fertilizer used in all treatments. On bo...

A 2 x 2 factorial experiment was conducted to study the effect of fertilization on Larix olgensis container seedlings. 36.36 or 18.18 mg controlled-release fertilizer (CRF) N and 0 or 1.82 g FM organic amendment (OA) per seedling were applied. There were no significant responses to fertilization in the seedling height, collar diameter, biomass, and...

In order to study potential contamination risk caused by leaching from bareroot seedling nursery to local ground waters, leaching of mineral nitrogen (N) and available phosphorus (P) was quantified in production of bareroot Changbai larch (Larix olgensis) seedlings, which is a common and economical tree species for afforestation and regeneration in...

Crown structure determining physiognomy of trees and influencing the harvest of light energy affects tree primary productivity. It can not only influence the shape of trees, but also influence flowering and fructification intensity, thus remarkably impact the ornamental value of trees. In order to reveal the relation ship between crown structure an...

Biomass allocation and assimilation efficiency of natural Amour linden (Tilia amurensis) samplings in different light regimes were analyzed in the paper. The results showed that shoot increment of samplings in gap was the highest and that of samplings under canopy was the least. Samplings in gap expressed apical dominance strongly but samplings in...

The necessity, basis, characteristic and methods of restoring and reestablishing broadleavcd / coniferous mixed forest ecosystem fronrthe secondary forest of Mongolian oak (Quercus mongolica)arc briefly set forth; then several effective methods of restoration and reestablishment are put forward and discussed as follows: openning up effect belt or...