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Drone remote sensing for forestry research and practices

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Journal of Forestry Research 2015年第4期26卷 791-797页

作者： Lina Tang guofan shao Institute of Urban Environment Chinese Academy of Sciences Department of Forestry and Natural Resources Purdue University

Drones of various shapes, sizes, and functionalities have emerged over the past few decades, and their civilian applications are becoming increasingly appealing. Flexible, low-cost, and high-resolution remote sensing systems that use drones as platforms are important for filling data gaps and supplementing the capabilities of crewed/manned aircraft and satellite remote sensing systems. Here, we refer to this growing remote sensing ini- tiative as drone remote sensing and explain its unique advantages in forestry research and practices. Furthermore, we summarize the various approaches of drone remote sensing to surveying forests, mapping canopy gaps, mea- suring forest canopy height, tracking forest wildfires, and supporting intensive forest management. The benefits of drone remote sensing include low material and operational costs, flexible control of spatial and temporal resolution, high-intensity data collection, and the absence of risk to crews. The current forestry applications of drone remote sensing are still at an experimental stage, but they are expected to expand rapidly. To better guide the development of drone remote sensing for sustainable forestry, it isimportant to systematically and continuously conduct comparative studies to determine the appropriate drone remote sensing technologies for various forest conditions and/or forestry applications.

关键词： Drone - Remote sensing UAV UAS UA -RPA· Forest

Measuring tree stem diameters and straightness with depth-image computer vision

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Journal of Forestry Research 2023年第5期34卷 1395-1405页

作者： Hoang Tran Keith Woeste Bowen Li Akshat Verma guofan shao Department of Computer Science Purdue University305 N University StWest LafayetteIN 47907USA Hardwood Tree Improvement and Regeneration Center USDA Forest ServiceNorthern Research Station715 West State StreetWest LafayetteIN 47907USA Department of Forestry and Natural Resources Purdue University715 West State StreetWest LafayetteIN 47907USA School of Electrical and Computer Engineering Purdue University610 Purdue MallWest LafayetteIN 47907USA

Current techniques of forest inventory rely on manual measurements and are slow and labor *** developments in computer vision and depth sensing can produce accurate measurement data at significantly reduced time and labor *** developed the ForSense system to measure the diameters of trees at various points along the stem as well as stem *** use,mean absolute error(MAE),and root mean squared error(RMSE)metrics were used to compare the system against manual methods,and to compare the system against itself(reproducibility).Depth-derived diameter measurements of the stems at the heights of 0.3,1.4,and 2.7 m achieved RMSE of 1.7,1.5,and 2.7 cm,*** ForSense system produced straightness measurement data that was highly correlated with straightness ratings by trained *** ForSense system was also consistent,achieving sub-centimeter diameter difference with subsequent measures and less than 4%difference in straightness value between *** method of forest inventory,which is based on depth-image computer vision,is time efficient compared to manual methods and less computationally and technologically intensive compared to Structure-from-Motion(SFM)photogrammetry and ground-based LiDAR or terrestrial laser scanning(TLS).

关键词： Forest inventory Depth sensing Computer vision Tree diameter Stem straightness Trunk volume

Practice and Research Progress on Ecosystem Conservation in Transboundary Areas

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Chinese Geographical Science 2016年第1期26卷 109-116页

作者： TANG Lina GUI Liuming shao guofan WANG Luyan SHI Longyu Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of Sciences Department of Forestry and Natural Resources Purdue University

Many ecosystems extend across national or political boundaries. The consistent and effective protection of these ecosystems in transboundary areas(ETAs) is an important global research focus. Previous research on the protection of such areas can be categorized into seven themes: 1) ecological conservation of a single ETA; 2) investigation of the effects of a single conservation measure on a specific ETA; 3) determination of species-level effects due to ETA conservation; 4) comparison of the same protection measures between different ETAs; 5) introduction of a single conservation measure to a specific ETA; 6) understanding the relationship between conservation and sustainable development; and 7) generalization across multiple ETA conservation cases. The protection of ETAs involves various considerations, including funding support, demand and will for collaboration, community and public participation, historical and cultural factors, political backgrounds, uniqueness of biological resources, formulation of laws and regulations, founding of specialized administrative departments, non-governmental organizations, and fairness. Here, we briefly explain the research themes and considerations related to ETA conservation. The most important finding is that most major research themes do not focus on the challenges of ETA conservation. We use two nature reserves located between China and North Korea as examples to identify specific ways to improve ETA conservation on Changbai Mountains. The efficiency of ETA administration still remains low. The study of ETA conservation should focus on concrete regional information and aim to improve existing measures through the accumulation of experience.

关键词： ecosystem in transboundary area (ETA) intemational cooperation transboundary cooperation regional sustainable development terrestrial ecosystem

A commentary review on the use of normalized diff erence vegetation index(NDVI)in the era of popular remote sensing

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Journal of Forestry Research 2021年第1期32卷 1-6页

作者： Sha Huang Lina Tang Joseph P.Hupy Yang Wang guofan shao School of Environmental and Geographical Sciences Shanghai Normal UniversityShanghai 200234People’s Republic of China Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021People’s Republic of China Department of Aviation and Transportation Technology Purdue UniversityWest LafayetteIN 47907USA Zhejiang GeeSpace Technology Co. LtdPurdue University1535 Hongmei RoadXuhui DistrictShanghai 200030People’s Republic of China Department of Forestry and Natural Resources Purdue UniversityWest LafayetteIN 47907USA

The Normalized Diff erence Vegetation Index(NDVI),one of the earliest remote sensing analytical products used to simplify the complexities of multi-spectral imagery,is now the most popular index used for vegetation *** popularity and widespread use relate to how an NDVI can be calculated with any multispectral sensor with a visible and a near-IR *** low costs and weights of multispectral sensors mean they can be mounted on satellite,aerial,and increasingly—Unmanned Aerial Systems(UAS).While studies have found that the NDVI is effective for expressing vegetation status andquantified vegetation attributes,its widespread use and popularity,especially in UAS applications,carry inherent risks of misuse with end users who received little to no remote sensing *** article summarizes the progress of NDVI acquisition,highlights the areas of NDVI application,and addresses the critical problems and considerations in using *** discussion mainly covers three aspects:atmospheric eff ect,saturation phenomenon,and sensor *** use of NDVI can be highly eff ective as long as its limitations and capabilities are *** consideration is particularly important to the UAS user community.

关键词： NDVI Atmospheric eff ect Saturation phenomenon Calibration Multispectral Near infrared UAS Drone remote sensing

Urban Three-dimensional Expansion and Its Driving Forces——A Case Study of Shanghai,China

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Chinese Geographical Science 2009年第4期19卷 291-298页

作者： SHI Longyu shao guofan CUI Shenghui LI Xuanqi LIN Tao YIN Kai ZHAO Jingzhu Institute of Urban Environment Chinese Academy of Sciences Xiamen 361003 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Forestry and Natural Resources Purdue University West Lafayette IN47907 USA

Urban expansion is a phenomenon of urban space increase,and an important measuring index of the process of *** Shanghai as an example,the changes of urban average height and built-up area were studied to represent city's vertical and horizontal increases respectively,and statistical methods were used to analyze the driving forces of urban *** research drew following conclusions:1) The urban expansion process of Shanghai from 1985 to 2006 had a clear periodic feature,and could be divided into three stages:vertical expansion in dominance,coordinated vertical and horizontal expansion,and horizontal expansion in dominance.2) The average height and quantity of buildings in core city were significantly bigger than those in suburbs,but the changing speed of the latter was *** 3) urbanization process was the major driving force for the city's horizontal expansion,while industrial structure improvement was the key driving factor for the vertical *** two driving forces were simultaneously affected by city's political factors.

关键词： urban expansion three-dimensional space urbanization urban vertical expansion urban horizontal ex-pansion Shanghai China

Digitally determining forest inventory units with an ecological classification system

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Science China(Technological Sciences) 2006年第Z1期49卷 118-127页

作者： TANG Una, WANG Qingli, guofan shao, DAI Limin, WANG Shunzhong, LI Xiufen & XU Dong Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Graduate University of Chinese Academy of Sciences, Beijing 100101, China Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Graduate University of Chinese Academy of Sciences Beijing China Department of Forestry and Natural Resources Purdue University West Lafayette USA

Management-level forest resource data in China were obtained with a combination of two forest inventories. However, inconsistencies in the spatial attributes of forest data vary between the two inventory types and between two inventories of the same type. The inconsistencies make it inconvenient for long-term forest management planning with digital technologies. Ecological Land Types (ELTs) and Ecological Land Type Phases (ELTPs) have been mapped in selected forestry regions in northeast China, where important forest industries are located. The boundaries of ELTs are determined by geomorphic conditions, which are quantified by Digital Elevation Models (DEM); ELTPs are classified by overlaying ELTs with forest vegetation data layers that are obtained with both remotely sensed and ground data. The ELTPs represent the divisions of land in terms of both natural and human-induced forest conditions, and therefore they are reliable units for forest inventories and management. This paper introduces a case study for digitally determining forest inventory units in Benxi City, Liaoning Province, northeast China. The general objective of the study was to explain how a compatible forest inventory system should be designed and why the compatible forest inventory system was significant to digital forestry in China.

关键词： forest inventory, ecological classification, ELT mapping, ELTP mapping, geographic information systems, forest management.

A density-dependent matrix model and its applications in optimizing harvest schemes

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Science China(Technological Sciences) 2006年第Z1期49卷 108-117页

作者： guofan shao, WANG Fei, DAI Limin, BAI Jianwei & LI Yingshan Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Inner Mongolia Agriculture University, Hohhot 010019, China Academy of Forest Inventory and Planning, State Forestry Administration, Beijing 100714, China Department of Forestry and Natural Resources Purdue University West Lafayette USA Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Inner Mongolia Agriculture University Hohhot China Academy of Forest Inventory and Planning State Forestry Administration Beijing China

Based on temporal data collected from 36 re-measured plots, transition probabilities of trees from a diameter class to a higher class were analyzed for the broad-leaved-Korean pine forest in the Changbai Mountains. It was found that the transition probabilities were related not only to diameter size but also to the total basal area of trees with the diameter class. This paper demonstrates the development of a density-dependent matrix model, DM2, and a series of simulations with it for forest stands with different conditions under different harvest schemes. After validations with independent field data, this model proved a suitable tool for optimization analysis of harvest schemes on computers. The optimum harvest scheme(s) can be determined by referring to stand growth, total timbers harvested, and size diversity changes over time. Three user-friendly interfaces were built with a forest management decision support system FORESTAR?for easy operations of DM2 by forest managers. This paper also summarizes the advantages and disadvantages of DM2.

关键词： uneven-aged forestry, diameter transition model, harvesting intensity, diameter limit, sustainable forest management.

Quantifying soil erosion with GIS-based RUSLE under different forest management options in Jianchang Forest Farm

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Science China(Technological Sciences) 2006年第Z1期49卷 160-166页

作者： ZHANG Hengming, WANG Qingli, DAI Limin, guofan shao, TANG Una, WANG Shunzhong & GU Huiyan Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Graduate University of Chinese Academy of Sciences, Beijing 100101, China Department of Forestry and Natural Resources, Purdue University, Lafayette IN47901, USA Northeast Forestry University, Harbin 150040, China Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Graduate University of Chinese Academy of Sciences Beijing China Department of Forestry and Natural Resources Purdue University Lafayette USA Northeast Forestry University Harbin China

Quantitatively estimating soil erosion with an integration of geographic information system (GIS) and the revised universal soil loss equation (RUSLE) under four different exposed soil proportion scenarios caused by forest management practices was studied at Jianchang Forest Farm. The GIS provided means of input data generation required by RUSLE model and allowed a spatial assessment of the erosion hazard over the study area. Four exposed soil proportion scenarios of 5%, 10%, 20% and 30% were tested with the GIS-based RUSLE model to evaluate soil erosion hazard. The predicted soil erosion potentials were classified into five categories in order to provide valuable aids for management planning.

关键词： geographic information system, RUSLE, soil erosion, forest management.

Digital forestry research in China

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Science China(Technological Sciences) 2006年第Z1期49卷 1-8页

作者： TANG Shouzheng, TANG Una, guofan shao & DAI Limin Research Institute of Resource Information Techniques, Chinese Academy of Forestry, Beijing 100091, China Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Departmet of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA Graduate University, Chinese Academy of Sciences, Beijing 100101, China Research Institute of Resource Information Techniques Chinese Academy of Forestry Beijing China Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Graduate University Chinese Academy of Sciences Beijing China Department of Forestry and Natural Resources Purdue University West Lafayette USA

Digital Forestry as a concept was developed after the Digital Earth program. The Chinese scientists were not only among the pioneers who first proposed the concept of Digital Forestry, but also contributed a lot to the development of Digital Forestry. Digital Forestry is a digital framework to maintain forest planting, management, using, and protect. The synergetic use of computationally-intensive quantitative methods together with information technologies is the most important foundation for the development of Digital Forestry. Under this situation, the experience of Digital Forestry development in China is relatively rich. A number of academicians, scholars, and professional administrators were involved in discussing the Digital Forestry Construction Scheme. The Project of Digital Forestry Practicability approved by the State Forestry Administration is a major instance in developing Digital Forestry standard and key techniques. By introducing a case study of Digital Forestry, this paper reviews the concept of Digital Forestry, the way turning traditional forestry into Digital Forestry, and the future development of Digital Forestry.

关键词： Digital Forest, Digital Earth, Digital Forestry standard, Digital Forestry techniques.