Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1016/j.foreco.2019.05.015 |
Characterizing light across a strip shelterwood in a mixed conifer forest | |
Hossain, Kazi Liaquat; Comeau, Philip G. | |
2019-08-01 | |
发表期刊 | FOREST ECOLOGY AND MANAGEMENT |
ISSN | 0378-1127 |
EISSN | 1872-7042 |
出版年 | 2019 |
卷号 | 445页码:134-145 |
文章类型 | Article |
语种 | 英语 |
国家 | Canada |
英文摘要 | A knowledge of how light varies within gaps is fundamental to understanding variation in survival and growth of regenerating trees. Simple indices based on a small number of instantaneous measurements by portable sensors or cameras are widely used for this purpose. But the effectiveness of these indices for estimating growing season transmittance is influenced by stand characteristics and local weather conditions. This study was conducted in two small (50 m x 150 m) clearings in a mixed stand of the interior cedar hemlock zone of southern British Columbia to evaluate several commonly used light estimation techniques, including: (1) hemispherical photography; (2) LAI-2000 plant canopy analyzer; and, (3) midday measurements of % photosynthetic photon flux density (hourly average PPFD) under sunny and overcast skies in a strip-shelterwood system. While diffuse indices from hemispherical methods (LAI-2000 and photograph) performed poorly, their direct and total indices (photograph) gave lower variability (lower rmse) and stronger correlations (higher r(2)) with growing season transmittance. Sky conditions under which light measurements were recorded by photosynthetically active radiation (PAR) sensors influenced the relationships between PAR sensor indices and growing season transmittance. For example, measuring light around midday on a sunny day provided stronger correlation with growing season transmittance than overcast day measurements. Moreover, rather than using one midday light measurement on a sunny or an overcast day, an average of two measurements increased r(2) and reduced bias while measuring light three times on a sunny day (morning, noon and afternoon) gave the highest r(2) and the lowest variability. Several indices also correlated strongly with monthly light levels, measured from May - September. Based on the finding that indices that accounted for direct beam contribution gave the best outcomes, we suggest that canopy conditions (degree of heterogeneity), stand orientation and gap sizes should be considered in selecting an instantaneous light index for studies in high latitude forests. |
英文关键词 | Light transmittance LAI-2000 Plant Canopy Analyzer Hemispherical photography Strip shelterwood |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000472690100013 |
WOS关键词 | PHOTON FLUX-DENSITY ; SOLAR-RADIATION ; UNDERSTORY LIGHT ; EFFICIENT METHOD ; CANOPY ; AVAILABILITY ; ENVIRONMENT ; TEMPERATE ; SURVIVAL ; HEMLOCK |
WOS类目 | Forestry |
WOS研究方向 | Forestry |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/185646 |
专题 | 气候变化 |
作者单位 | Univ Alberta, Renewable Resources, 751 Gen Serv Bldg, Edmonton, AB T6G 2H1, Canada |
推荐引用方式 GB/T 7714 | Hossain, Kazi Liaquat,Comeau, Philip G.. Characterizing light across a strip shelterwood in a mixed conifer forest[J]. FOREST ECOLOGY AND MANAGEMENT,2019,445:134-145. |
APA | Hossain, Kazi Liaquat,&Comeau, Philip G..(2019).Characterizing light across a strip shelterwood in a mixed conifer forest.FOREST ECOLOGY AND MANAGEMENT,445,134-145. |
MLA | Hossain, Kazi Liaquat,et al."Characterizing light across a strip shelterwood in a mixed conifer forest".FOREST ECOLOGY AND MANAGEMENT 445(2019):134-145. |
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