Zhenkai Sun

Dr. Zhenkai Sun


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 January 2021 in Forests
Verified
Journal Article
Open access
PDF file
Dan HanDan Han
Dan Han
CZChang Zhang
Chang Zhang
CWCheng Wang
Cheng Wang
JSJunying She
Junying She
ZSZhenkai Sun
Zhenkai Sun
HCHe Cheng
He Cheng
Background and Objectives: As urbanisation is a significant global trend, there is a profound need for biodiversity protection in urban ecosystems. Moreover, the potential of urban green space to support urban biodiversity should be appreciated. Butterflies are environmental indicators that are sensitive to urbanisation. Therefore, it is important to identify butterfly distribution patterns and the factors influencing butterfly diversity and species composition in urban parks within cities. Research Highlights: To our knowledge, ours is the first study evaluating the effects of both land cover and local habitat features on butterfly species composition in urban parks of Beijing, China. Materials and Methods: In this study, we surveyed butterfly richness and abundance in 28 urban parks in Beijing, China. The parks differed in age and location in the urban area. Meanwhile, we investigated the green space in the surroundings of the parks at multi-spatial scales at the landscape level. We also investigated local park characteristics including the age of the park (Age), perimeter/area ratio of the park (SQPRA), area of the park (ha) (Area), green space cover within the park (Greenp), nectar plant species richness (Necpl), abundance of flowering nectar plants (Necabu) and overall plant species richness (Pl). Generalised linear models (GLMs) and redundancy discriminant analysis (RDA) were applied to relate butterfly diversity and butterfly species composition to environmental variables, respectively. Results: We recorded 3617 individuals belonging to 26 species from July to September in 2019. Parks on the city fringe had significantly higher butterfly diversity. Butterfly species richness was mostly related to total plant richness. The abundance of flowering nectar plants was closely linked to butterfly abundance. Land cover had little impact on butterfly diversity and community structure in urban parks. Conclusions: Once a park has sufficient plants and nectar resources, it becomes a useful haven for urban butterflies, regardless of the surrounding land cover. Well-planned urban parks focused on local habitat quality support butterfly conservation.

26 March 2021 in Forests
Verified
Journal Article
Open access
PDF file
XXXinhui Xu
Xinhui Xu
ZSZhenkai Sun
Zhenkai Sun
zezhou haozezhou hao
zezhou hao
QBQi Bian
Qi Bian
KWKaiyue Wei
Kaiyue Wei
CWCheng Wang
Cheng Wang
Forests can affect soil organic carbon (SOC) quality and distribution through forest types and traits. However, much less is known about the influence of urban forests on SOC, especially in the effects of different forest types, such as coniferous and broadleaved forests. Our objectives were to assess the effects of urban forest types on the variability of SOC content (SOC concentration (SOCC) and SOC density (SOCD)) and determine the key forest traits influencing SOC. Data from 168 urban forest plots of coniferous or broadleaved forests located in the Beijing urban area were used to predict the effects of forest types and traits on SOC in three different soil layers, 0–10 cm, 10–20 cm, and 20–30 cm. The analysis of variance and multiple comparisons were used to test the differences in SOC between forest types or layers. Partial least squares regression (PLSR) was used to explain the influence of forest traits on SOC and select the significant predictors. Our results showed that in urban forests, the SOCC and SOCD values of the coniferous forest group were both significantly higher than those of the broadleaved group. The SOCC of the surface soil was significantly higher than those of the following two deep layers. In PLSR models, 42.07% of the SOCC variance and 35.83% of the SOCD variance were explained by forest traits. Diameter at breast height was selected as the best predictor variable by comparing variable importance in projection (VIP) scores in the models. The results suggest that forest types and traits could be used as an optional approach to assess the organic carbon stock in urban forest soils. This study found substantial effects of urban forest types and traits on soil organic carbon sequestration, which provides important data support for urban forest planning and management.

9 July 2025 in Sustainability
Verified
Journal Article
Open access
PDF file
Dan HanDan Han
Dan Han
CWCheng Wang
Cheng Wang
JSJunying She
Junying She
ZSZhenkai Sun
Zhenkai Sun
LYLuqin Yin
Luqin Yin
(1) Background: Urban parks play a critical role in conserving biodiversity within city landscapes, yet the effects of fine-scale microhabitat heterogeneity remain poorly understood. This study examines how land cover and vegetation unit type within parks influence butterfly diversity. (2) Methods: From July to September 2019 and June to September 2020, adult butterflies were surveyed in 27 urban parks across Beijing. We classified vegetation into units based on vertical structure and management intensity, and then applied the patch–matrix framework and landscape metrics to quantify fine-scale heterogeneity in vegetation unit composition and configuration. Generalized linear models (GLM), generalized additive models (GAM), and random forest (RF) models were applied to identify factors influencing butterfly richness (Chao1 index) and abundance. (3) Results: In total, 10,462 individuals representing 37 species, 28 genera, and five families were recorded. Model results revealed that the proportion of park area covered by spontaneous herbaceous areas (SHA), wooded spontaneous meadows (WSM), and the Shannon diversity index (SHDI) of vegetation units were positively associated with butterfly species richness. In contrast, butterfly abundance was primarily influenced by the proportion of park area covered by cultivated meadows (CM) and overall green-space coverage. (4) Conclusions: Fine-scale vegetation patch composition within urban parks significantly influences butterfly diversity. Our findings support applying the patch–matrix framework at intra-park scales and suggest that integrating spontaneous herbaceous zones—especially wooded spontaneous meadows—with managed flower-rich meadows will enhance butterfly diversity in urban parks.

11 April 2025 in Forests
Verified
Journal Article
Open access
PDF file
YZYilin Zhao
Yilin Zhao
ZSZhenkai Sun
Zhenkai Sun
ZBZitong Bai
Zitong Bai
JJJiali Jin
Jiali Jin
CWCheng Wang
Cheng Wang
Urban green spaces are critical yet understudied areas where anthropogenic and biological sounds interact. This study investigates how vegetation structure mediates the acoustic partitioning of urban soundscapes and informs sustainable forestry management. Through the principal component analysis (PCA) of 1–11 kHz frequency bands, we identified anthropogenic sounds (1–2 kHz) and biological sounds (2–11 kHz). Within bio-acoustic communities, PCA further revealed three positively correlated sub-clusters (2–4 kHz, 5–6 kHz, and 6–11 kHz), suggesting cooperative niche partitioning among avian, amphibian, and insect vocalizations. Linear mixed models highlighted vegetation’s dual role: mature tree stands (explaining 19.9% variance) and complex vertical structures (leaf-height diversity: 12.2%) significantly enhanced biological soundscapes (R2m = 0.43) while suppressing anthropogenic noise through canopy stratification (32.3% variance explained). Based on our findings, we suggest that an acoustic data-driven framework—comprising (1) the preservation of mature stands with multi-layered canopies to enhance bioacoustic resilience, (2) strategic planting of mid-story vegetation to disrupt low-frequency noise propagation, and (3) real-time soundscape monitoring to balance biophony and anthropophony allocation—can contribute to promoting sustainable urban forestry management.

8 February 2022 in Forests
Verified
Journal Article
Open access
PDF file
YZyilin zhao
yilin zhao
Jingli YanJingli Yan
Jingli Yan
Jiali JinJiali Jin
Jiali Jin
ZSZhenkai Sun
Zhenkai Sun
LYLuqin Yin
Luqin Yin
CWCheng Wang
Cheng Wang
In the context of rapid urbanization, urban foresters are actively seeking management monitoring programs that address the challenges of urban biodiversity loss. Passive acoustic monitoring (PAM) has attracted attention because it allows for the collection of data passively, objectively, and continuously across large areas and for extended periods. However, it continues to be a difficult subject due to the massive amount of information that audio recordings contain. Most existing automated analysis methods have limitations in their application in urban areas, with unclear ecological relevance and efficacy. To better support urban forest biodiversity monitoring, we present a novel methodology for automatically extracting bird vocalizations from spectrograms of field audio recordings, integrating object-based classification. We applied this approach to acoustic data from an urban forest in Beijing and achieved an accuracy of 93.55% (±4.78%) in vocalization recognition while requiring less than ⅛ of the time needed for traditional inspection. The difference in efficiency would become more significant as the data size increases because object-based classification allows for batch processing of spectrograms. Using the extracted vocalizations, a series of acoustic and morphological features of bird-vocalization syllables (syllable feature metrics, SFMs) could be calculated to better quantify acoustic events and describe the soundscape. A significant correlation between the SFMs and biodiversity indices was found, with 57% of the variance in species richness, 41% in Shannon’s diversity index and 38% in Simpson’s diversity index being explained by SFMs. Therefore, our proposed method provides an effective complementary tool to existing automated methods for long-term urban forest biodiversity monitoring and conservation.

7 October 2025 in Forests
Verified
Journal Article
Open access
PDF file
QHQingqing Huang
Qingqing Huang
HZHaicong Zeng
Haicong Zeng
CYChaodong Yan
Chaodong Yan
TLTing Liu
Ting Liu
SLSongsong Liu
Songsong Liu
CWCheng Wang
Cheng Wang
Against the backdrop of advancing ecological civilization and increasing public interest in reconnecting with nature, this study examines fireflies—iconic insects cherished for their natural charm—as valuable landscape resources. This study was conducted in Dalingshan Forest Park, Dongguan (Pearl River Delta), using the Forest Science Trail as a sampling site. Surveys combining line transect and point count methods were employed to analyze firefly species composition, adult activity patterns, and flight characteristics. Key findings include: (1) Four species were identified—Asymmetricata circumdata, Pygoluciola qingyu, Aquatica analis, and Luciola satoi—three of which were observed along the trail; (2) Adults appeared sporadically after 19:00, with peak activity occurring between 19:30 and 20:00, showing minor interspecific variation; (3) Although flight height varied slightly among species, most activities concentrated within 0–1.5 m, corresponding to herbaceous and shrub layers; (4) Distinct flight patterns were observed: A. circumdata displayed prolonged intermittent flights, while P. qingyu and L. satoi exhibited shorter perching-based flights. These results provide a scientific basis for firefly habitat conservation, biodiversity promotion, and the sustainable integration of firefly landscapes into nature education and ecotourism.