- Book学术

发布求助

文献互助智能选刊最新文献

IF 2.1 3区农林科学 Q2 FORESTRY

Trees Pub Date : 2024-12-14 DOI:10.1007/s00468-024-02589-4

Hongliang Fang, Yunjia Wu, Yinghui Zhang, Yao Wang, Sijia Li, Tian Ma, Yu Li, Keruo Guo

{"title":"Seasonal variation of canopy vertical structural profiles measured at two temperate forests: intercomparison of tower, mast, crane, and UAV measurements","authors":"Hongliang Fang, Yunjia Wu, Yinghui Zhang, Yao Wang, Sijia Li, Tian Ma, Yu Li, Keruo Guo","doi":"10.1007/s00468-024-02589-4","DOIUrl":null,"url":null,"abstract":"<div><h3>Key message</h3><p>Evaluated tower, mast, crane, and UAV methods for forest vertical gap fraction, LAI, and CI measurements in different seasons. UAV is promising for forest vertical structural profiling.</p><h3>Abstract</h3><p>The vertical distribution of canopy structural parameters, such as canopy gap fraction, leaf area index (LAI) and clumping index (CI), is important for understanding the forest structural and functional properties. However, vertically distributed canopy structural data are rare, and current methods are either inefficient or costly for obtaining sufficient amounts of such data. This study conducted a series of field campaigns to obtain forest vertical structural measurements at two temperate forest sites in northern China from 2020 to 2023. Four different measurement systems were compared: (1) flux towers with accessible platforms at different heights, (2) a portable and extensible sampling mast with a digital hemispherical photography (DHP) camera attached on top, (3) a tower crane with a DHP camera fixed on the crane hook, and (4) an uncrewed aerial vehicle (UAV) with a DHP camera attached on top. The measured effective plant area index (PAI<sub>eff</sub>) shows clearly seasonal variations at different heights. The CI remains relatively consistent at different heights, and the leaf-off value is approximately 0.1−0.2 higher than the leaf-on one. The flux tower method can be used for vertical profile measurement at a fixed location, whereas the portable mast is suitable for lower-level (< 15 m) measurement. Crane measurement requires an established facility and is useful for local measurement around the crane. UAV with an attached DHP provides a promising method for monitoring vertical structural parameters. The vertical structural profiles obtained in this study can be used in various modeling and validation studies.</p></div>","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 1","pages":""},"PeriodicalIF":2.1000,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-024-02589-4.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Trees","FirstCategoryId":"2","ListUrlMain":"https://link.springer.com/article/10.1007/s00468-024-02589-4","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"FORESTRY","Score":null,"Total":0}

引用次数: 0

摘要

关键信息评估了塔式、桅杆式、吊车式和无人机在不同季节测量森林垂直间隙率、叶面积指数和CI的方法。摘要冠层结构参数（如冠层间隙率、叶面积指数（LAI）和团聚指数（CI））的垂直分布对于了解森林结构和功能特性非常重要。然而，垂直分布的冠层结构数据非常罕见，而且目前的方法要么效率低下，要么成本高昂，无法获得足够数量的此类数据。本研究从 2020 年到 2023 年在中国北方的两个温带森林地点开展了一系列野外活动，以获取森林垂直结构测量数据。对四种不同的测量系统进行了比较：（1）不同高度的通量塔和无障碍平台；（2）顶部装有数字半球摄影（DHP）相机的便携式可伸缩采样桅杆；（3）塔式起重机，其吊钩上固定有 DHP 相机；以及（4）顶部装有 DHP 相机的无人驾驶飞行器（UAV）。测得的有效植物面积指数（PAIeff）在不同高度有明显的季节性变化。在不同高度，CI 保持相对一致，落叶值比开叶值高约 0.1-0.2。通量塔法可用于固定地点的垂直剖面测量，而便携式桅杆则适用于较低高度（15 米）的测量。起重机测量需要固定的设施，适用于起重机周围的局部测量。附带 DHP 的无人机为监测垂直结构参数提供了一种可行的方法。本研究获得的垂直结构剖面图可用于各种建模和验证研究。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

查看原文本刊更多论文

Seasonal variation of canopy vertical structural profiles measured at two temperate forests: intercomparison of tower, mast, crane, and UAV measurements

Key message

Evaluated tower, mast, crane, and UAV methods for forest vertical gap fraction, LAI, and CI measurements in different seasons. UAV is promising for forest vertical structural profiling.

Abstract

The vertical distribution of canopy structural parameters, such as canopy gap fraction, leaf area index (LAI) and clumping index (CI), is important for understanding the forest structural and functional properties. However, vertically distributed canopy structural data are rare, and current methods are either inefficient or costly for obtaining sufficient amounts of such data. This study conducted a series of field campaigns to obtain forest vertical structural measurements at two temperate forest sites in northern China from 2020 to 2023. Four different measurement systems were compared: (1) flux towers with accessible platforms at different heights, (2) a portable and extensible sampling mast with a digital hemispherical photography (DHP) camera attached on top, (3) a tower crane with a DHP camera fixed on the crane hook, and (4) an uncrewed aerial vehicle (UAV) with a DHP camera attached on top. The measured effective plant area index (PAI_eff) shows clearly seasonal variations at different heights. The CI remains relatively consistent at different heights, and the leaf-off value is approximately 0.1−0.2 higher than the leaf-on one. The flux tower method can be used for vertical profile measurement at a fixed location, whereas the portable mast is suitable for lower-level (< 15 m) measurement. Crane measurement requires an established facility and is useful for local measurement around the crane. UAV with an attached DHP provides a promising method for monitoring vertical structural parameters. The vertical structural profiles obtained in this study can be used in various modeling and validation studies.

求助全文

通过发布文献求助，成功后即可免费获取论文全文。去求助

来源期刊

Trees 农林科学-林学

CiteScore

4.50

自引率

4.30%

发文量

113

审稿时长

3.8 months

期刊介绍： Trees - Structure and Function publishes original articles on the physiology, biochemistry, functional anatomy, structure and ecology of trees and other woody plants. Also presented are articles concerned with pathology and technological problems, when they contribute to the basic understanding of structure and function of trees. In addition to original articles and short communications, the journal publishes reviews on selected topics concerning the structure and function of trees.