He Liu

Dr. He Liu

Senior advisor
orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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30 October 2015 in Forests
Verified
Journal Article
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SXShaobo Xia
Shaobo Xia
Cheng WangCheng Wang
Cheng Wang
Feifei PanFeifei Pan
Feifei Pan
XXXiaohuan Xi
Xiaohuan Xi
HZHongcheng Zeng
Hongcheng Zeng
HLHe Liu
He Liu
Stem characteristics of plants are of great importance to both ecology study and forest management. Terrestrial laser scanning (TLS) may provide an effective way to characterize the fine-scale structures of vegetation. However, clumping plants, dense foliage and thin structure could intensify the shadowing effect and pose a series of problems in identifying stems, distinguishing neighboring stems, and merging disconnected stem parts in point clouds. This paper presents a new method to automatically detect stems in dense and homogeneous forest using single-scan TLS data. Stem points are first identified with a two-scale classification method. Then a clustering approach is used to group the candidate stem points. Finally, a direction-growing algorithm based on a simple stem curve model is applied to merge stem points. Field experiments were carried out in two different bamboo plots with a stem density of about 7500 stems/ha. Overall accuracy of the stem detection is 88% and the quality of detected stems is mainly affected by the shadowing effect. Results indicate that the proposed method is feasible and effective in detection of bamboo stems using TLS data, and can be applied to other species of single-stem plants in dense forests.

20 January 2017 in PLOS ONE
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Journal Article
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HLHe Liu
He Liu
HDHejun Duan
Hejun Duan
CWCheng Wang
Cheng Wang
Stereotypies are commonly observed in zoo animals, and it is necessary to better understand whether ambient environmental factors contribute to stereotypy and how to affect animal welfare in zoo settings. This study investigated the relationships between stereotypic behaviors and environmental factors including ambient temperatures, humidity, light intensity, sound intensity and number of visitors. Seven giant pandas were observed in three indoor enclosures and three outdoor enclosures. Environmental factors were measured for both indoor and outdoor enclosures and the effect they had on stereotypical behaviors was investigated. Our research found that light intensity significantly correlated with all stereotypies behaviors. Higher environmental temperature reduced the duration of pacing but increased the frequency of pacing, the duration and frequency of door-directed, meanwhile the duration of head-toss. However, we found no noticeable effect of humidity on stereotypic behaviors except for the frequency of head-toss. We also found that sound intensity was not correlated with stereotypies. Finally, the growth of visitors was negatively associated with the duration of door-directed. These results demonstrated that various environmental factors can have significant effects on stereotypic behaviors causing the expression of various stereotypies. Thus, stereotypies in zoo animals may not simply represent suboptimal welfare, but rather might be adopted as a means of coping with an aversive environment.

11 March 2021 in Animals
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Journal Article
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HLHe Liu
He Liu
YTYezhong Tang
Yezhong Tang
YNYanxia Ni
Yanxia Ni
Guangzhan FangGuangzhan Fang
Guangzhan Fang
Cerebral lateralization is a common feature present in many vertebrates and is often observed in response to various sensory stimuli. Numerous studies have proposed that some vertebrate species have a right hemisphere or left hemisphere dominance in response to specific types of acoustic stimuli. We investigated lateralization of eight giant pandas (Ailuropoda melanoleuca) by using a head turning paradigm and twenty-eight acoustic stimuli with different emotional valences which included twenty-four conspecific and four non-conspecific acoustic stimuli (white noise, thunder, and vocalization of a predator). There was no significant difference in auditory laterality in responses to conspecific or non-conspecific sounds. However, the left cerebral hemisphere processed the positive stimuli, whereas neither of the two hemispheres exhibited a preference for processing the negative stimuli. Furthermore, the right hemisphere was faster than the left hemisphere in processing emotional stimuli and conspecific stimuli. These findings demonstrate that giant pandas exhibit lateralization in response to different acoustic stimuli, which provides evidence of hemispheric asymmetry in this species.

9 September 2023 in Veterinary Medicine and Science
Verified
Journal Article
Open access
HLHe Liu
He Liu
YLYan Liu
Yan Liu
FHFeier Hao
Feier Hao
BLBo Li
Bo Li
YCYipeng Cong
Yipeng Cong
Objective: The prevalence of prebiotic has increased substantially over the past decades. Little is known on its metabolic effects in zoo herbivores. We investigated the difference in faecal metabolites to characterize the composition and pathways involved after feeding inulin in zoo Baird's tapirs (Tapirus bairdii).Methods: Faecal samples were collected from before inulin treatment group and after treatment groups in six adult tapirs and analysed using untargeted liquid chromatography–mass spectrometry methods. The differential metabolites identified and metabolic pathways involved were analysed using KEGG annotation.Results: The results demonstrated significant alterations in faecal metabolites and metabolic pathways in comparison to the control group. The amounts of differential metabolites and metabolic pathways tended to enrich with time after the treatment. We found that tryptophan and purine metabolism were relevant to the important metabolic pathways of the metabolite differences.Conclusions: The findings suggest that inulin may have potential applications in captive wildlife, which may provide insights into the effects of prebiotic supplementation on gut metabolites and highlights further research in this field.