Dynamics of leaf area index and canopy openness of three forest types in a warm temperate zone

Abstract

Deciduous broad-leaved forests (DBF), Larix principis-rupprechtii (LF) and Pinus tabulaeformis plantations (PF) are three typical forest communities in the warm temperate zone of the Dongling Mountains. In this study, we used an indirect method, hemispheric photography, to measure and analyze the dynamics of leaf area index (LAI) and canopy openness of the three forest communities. The results show that the LAI values of DBF and LF increased gradually with plant growth and development. The highest LAI value appeared in August, while canopy openness changed inversely with LAI. The lowest value appeared in November. DBF maintained a higher LAI in August and had a more open canopy in November compared with LF. For PF, we observed little changes in the LAI and canopy openness which was attributed to the leaf retention of this evergreen species. However, a similar relation between LAI and canopy openness was found for the three forest communities: canopy openness varied inversely with LAI. The relation is exponential and significant. Therefore, canopy openness is a good indicator of LAI in forests. This result can be used to test the validity of the LAI based on remote sensing and to provide a reference for the study of the canopy heterogeneity and its effect. This also benefits modeling for fluxes of carbon, water and energy from the level of the stand to landscape.

References

1. Chen J M (1996). Optically-based methods for estimating seasonal variationof leaf area index in boreal conifer stand. Agric For Meteorol, 80: 135–163. doi:10.1016/0168-1923(95)02291-0
2. Chen J M, Cihlar J (1996). Retrievingleaf area index of boreal conifer forests using landsat TM images. Remote Sens Environ, 55(2): 153–162. doi:10.1016/0034-4257(95)00195-6
3. Chen L Z, Huang J H (1997). Studyon the Characteristics and Function of the Forest Ecosystem in theWarm Temperate Zone. Beijing: Science Press (in Chinese)
4. Eriksson H, Eklundh L, Hall K, Lindroth A (2005). Estimating LAI in deciduous forest stands. Agric For Meteorol, 129(1–2): 27–37. doi:10.1016/j.agrformet.2004.12.003
5. Fang S Z, Xu X Z, Lu S X, Tang L Z, Cao F L (1998). Leaf area index andbiomass productivity of mid- and short rotation poplar plantationsfor pulp timber. Chin J Appl Ecol, 9(3): 225–230 (in Chinese)
6. Fang X Q, Zhang W C (2003). The applicationof remotely sensed data to the estimation of the leaf area index. Remote Sens Land Resour. 57(3): 58–62 (in Chinese)
7. Fassnacht K S, Gower S T, Norman J M, McMurtrie R E (1994). A comparison of optical and direct methods for estimatingfoliage surface area index in forests. Agric For Meteorol, 71: 183–207. doi:10.1016/0168-1923(94)90107-4
8. Frazer G W, Canham C D, Lertzman K P (1999). Gap Light Analyzer (GLA), Version2.0: Imaging Software to Extract Canopy Structure and Gap Light TransmissionIndices from True-colour Fisheye Photographs, Users Manual and ProgramDocumentation.Millbrook, New York: Simon FraserUniversity, Burnaby, British Columbia, and the Institute of EcosystemStudies
9. Gholz H L (1982). Environmental limits on above-ground net primary production,leaf area and biomass in vegetation zones of the Pacific North West. Ecology, 63(2): 469–481. doi:10.2307/1938964
10. Hu L J, Shao M A (2001). Vegetationcoverage index in soil and water loss studies. J Northwest For Univ. 16(1): 40–43 (in Chinese)
11. Hui F M, Tian Q J, Jin Z Y, Li H T (2003). Research and quantitative analysis of the correlation between vegetationindex and leaf area index. Remote SensInf, 2: 10–13 (in Chinese)
12. Jonckheere I, Fleck S, Nackaerts K, Muys B, Coppinhttp P, Weiss M, Baret F (2004). Reviewif methods for in situ leaf area index determination. Part I. Theories,sensors and hemispherical photograph.Agric For Meteorol, 121(1–2): 19–35. doi:10.1016/j.agrformet.2003.08.027
13. Kucharik C J, Norman J M, Gower S T (1998). Measurements of branch area and adjustingleaf area index indirect measurements. Agric For Meteorol, 91: 69–88. doi:10.1016/S0168-1923(98)00064-1
14. Lassoies J, Hinckely T M (1991). Techniquesand Approaches in Forest Physiology. Boca Raton: CRC Press
15. Li X W, Wang J D (1995). PlantPhoton Remote Sensing Model and Parameterizing of Plant Structure. Beijing: Science Press (inChinese)
16. Liu J, He W M, Fang Z L (2005). Spatial characteristics of soil moistureand organic matter and light in Pinus tabulaeformis forest and Quercus liaotungensis forest on Dongling Mountain, Beijing, China. Acta Ecol Sin, 25(11): 2954–2960 (in Chinese)
17. McNaughton KG, Jarvis P G (1983). Predictingeffects of vegetation on changes on transpiration and evaporation. In: Kozlowski T T ed. Water Deficits and Plant Growth. London: Academic Press, 718
18. Pierce L L, Running S W (1988). Rapidestimation of coniferous forest leaf area index using a portable integratingradiometer. Ecology, 69(6): 1762–1767. doi:10.2307/1941154
19. Running S W, Coughlan J C (1988). A generalmodel of forest ecosystem processes for regional applications. I.Hydrologic balance, canopy gas exchange and primary production processes.Ecol Model, 42: 125–154. doi:10.1016/0304-3800(88)90112-3
20. Vales D J, Bunnell F L (1988). Comparisonof methods for estimating forest overstory cover I. Observer effects.Can J For Res, 18(5): 606–609. doi:10.1139/x88-088
21. Wang X Q, Ma L Y, Jia Z K, Xu C Y (2005). Research and application advances in leaf area index. Chin J Ecol, 24(5): 537–541 (in Chinese)
22. Zhang H Q, Chen Y R, Niu D (2004). Retrieving effective leaf area indexof conifer forests using Landsat TM Images in red soil hilly region. Acta Agric Univ Jiangxi, 26(2): 159–163 (in Chinese)
23. Zhang J H (2001). Study on models for evaluating primary productivityof natural vegetation and crop yield. ActaAgric Shanghai, 17(3): 83–89 (in Chinese)
24. Zhang Z P (1990). The radiation absorption efficiency of photosynthesisof the forest communities in the Dinghu Mountain. Acta Phytoecol Geobot Sin, 14(2): 139–150 (in Chinese)
25. Zhao P, Zeng X P, Cai X A, Peng S L (2002). Report on measurement of leaf area index of low subtropical forestsby using digital plant canopy imager. Guihaia, 22(6): 485–489 (in Chinese)
26. Zhou Y Y, Tang S H, Zhu Q J, Li J T, Sun R, Liu S H (2003). Measurement of LAI in Changbai Mountains nature reserve and its result. Res Sci, 25(6): 20–25 (in Chinese)
27. Zhu C Q, Lei J P, Liu X D, Wang F G, Cheng G Z (2001). The distributionand seasonal change of leaf area in poplar plantations managed indifferent ways. Sci Silv Sin, 37(1): 46–51 (in Chinese)
28. Zhu J J (2003). Method for measurement of optical stratification porosity(OPS) and its application in studies of management for secondary forests. Chin J Appl Ecol, 14(8): 1229–1233 (in Chinese)