Abstract
The article, in relation to the importance of canopy cover as stand density and biodiversity indicator, describes the main related field measurement techniques. In particular the authors emphasize the distinction between canopy cover and canopy closure when forest cover is usually measured through the current techniques. After a conceptual clarification the study focuses on the comparison of three ground-based canopy cover estimation techniques and two ground-based canopy closure estimation techniques, analyzing the data collected in a test carried out on Alpine stands. As expected, the results indicate that some techniques [GRS densiometer, visual estimation and hemispherical photographs (HP) assessed with a narrow angle of view] are more suitable to measure canopy cover, while others (spherical densiometer and HP with a wide angle of view) are more adapted to estimate canopy closure. In general, the techniques that use a wide angle of view tend to overestimate the canopy cover.
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Notes
The best correspondence of projected area is reached with stand heights around 29 m.
References
Avery TE, Burkart HE (1994) Forest measurements. McGraw-Hill, New York, p 331
Bebi P, Kienast F, Schönenberger W (2001) Assessing structures in mountain forests as a basis for investigating the forests’ dynamics and protective function. For Ecol Manage 145:3–14
Bechtold WA, Zarnoch SJ (2002) Comparison of field methods and models to estimate mean crown diameter. North J Appl For 19(4):177–182
Berger F, Rey F (2004) Mountain protection forests against natural hazards and risks: new french developments by integrating forests in risk zoning. Nat Hazards 33:395–404
Bonnor GM (1967) Estimation of ground canopy density from ground measurements. J For 65:544–547
Braun-Blanquet J (1928) Pflanzensoziologie. Springer, Wien, p 330
Bunnell FL, Vales DJ (1990) Comparison of methods for estimating forest overstory cover: differences among techniques. Can J For Res 20:101–107
Cook JG, Stutzman TW, Bowers CW, Brenner KA, Irwin LL (1995) Spherical densiometers produce biased estimates of forest canopy cover. Wildl Soc Bull 23(4):711–717
Crookston NL, Stage AR (1999) Percent canopy cover and stand structure statistics from the forest vegetation simulator. General technical report forest service, USDA, Ogden, 11p
Daubenmire R (1959) A canopy-coverage method of vegetation analysis. Northwest Sci 33:43–64
Englund SR, O’Brien JJ, Clark DB (2000) Evaluation of digital and film hemispherical photography and spherical densiometry for measuring forest light environments. Can J For Res 30:1999–2005
FAO (2001) Global forest resources assessment 2000. Main report, Food and Agriculture Organization of the United Nations, Rome
Fassnacht KS, Gower ST, Norman JM, McMurtrie RE (1994) A comparison of optical and direct methods for estimating foliage surface area index in forests. Agric For Meteorol 71:183–207
Fiala ACS, Garman SL, Gray AN (2006) Comparison of five canopy cover estimation techniques in the western Oregon Cascades. For Ecol Manage 1–3:188–197
Frazer GW, Fournier RA, Trofymow JA, Hall RJ (2001) A comparison of digital and film fisheye photography for analysis of forest canopy structure and gap light transmission. Agric For Meteorol 109:249–263
Ganey JL, Block WM (1994) A comparison of two techniques for measuring canopy closure. West J Appl For 9(1):21–23
Gill SJ, Biging GS, Murphy EC (2000) Modeling conifer tree crown radius and estimating canopy cover. For Ecol Manage 126:405–416
Hale AM (1980) An optical canopy cover instrument. Ohio J Sci 80(3):125–128
Jennings SB, Brown ND, Sheil D (1999) Assessing forest canopies and understorey illumination: canopy closure, canopy cover and other measures. Forestry 72(1):59–74
Johansson T (1985) Estimating canopy density by the vertical tube method. For Ecol Manage 11:139–144
Knowles RL, Horvath GC, Carter MA, Hawke MF (1999) Developing a canopy closure model to predict overstory/understorey relationship in Pinus radiata silvopastoral systems. Agroforest Syst 43:109–110
Korhonen L, Korhonen KT, Rautiainen M, Stenberg P (2006) Estimation of forest canopy cover: a comparison of field measurement techniques. Silva Fenn 40(4):577–588
Lemmon PE (1956) A spherical densiometer for estimating forest overstory density. For Sci 2(4):314–320
McConnell BR, Smith JG (1970) Response of understory vegetation to ponderosa pine thinning in eastern Washinghton. J Range Manage 23:208–212
Morrison ML, Marcot BG, Mannan RW (1999) Wildlife–habitat relationships: concepts and applications. J Mammal 80(4):1382–1385
Motta R, Haudemand JC (2000) Protective forests and silvicultural stability. Mt Res Dev 20:74–81
Müller S, Ammer C, Nüsslein S (2000) Analyses of stand structure as a tool for silvicultural decisions—a case study in a Quercus petraea—Sorbus torminalis stand. Forstw Cbl 119:32–42
O’Brien RA (1989) Comparison of overstory canopy cover estimates on forest survey plots. Intermountain research station research paper 417. USDA Forest Service, Ogden, pp1–5
Pignatti S (1953) Introduzione allo studio fitosociologico della Pianura Veneta Orientale. Arch Bot 28(4):28–29
Rautiainen M, Stenberg P, Nilson T (2005) Estimating canopy cover in Scots pine stands. Silva Fenn 39(1):137–142
Stumpf KA (1993) The estimation of forest vegetation cover descriptions using a vertical densitometer. Geographic resource solutions. Paper presented at the joint inventory and biometrics working groups session at the SAF National Convention held at Indianapolis, 8–10 November 1993. www.grsgis.com/publications/saf_93.html
Tabacchi G, De Natale F, Floris A, Gasparini P, Gagliano C, Scrinzi G, Tosi V (2007) Italian national forest inventory: methods, state of the project and future developments. In: Proceedings of the 7th annual forest inventory and analysis symposium, 3–6 October 2005, Portland, pp 55–66
Van Hees WWS, Mead BR (2000) Ocular estimates of understory vegetation structure in a closed Picea glauca/Betula papyrifera forest. J Veg Sci 11:195–200
Winter S, Chirici G, McRoberts RE, Hauk E, Tomppo E (2008) Possibilities for harmonizing national forest inventory data for use in forest biodiversity assessments. Forestry 81:33–44
Zhang Y, Chen JM, Miller JR (2005) Determining digital hemispherical photograph exposure for leaf area index estimation. Agric For Meteorol 133:166–181
Zollner PA, Crane KJ (2003) Influence of canopy closure and shrub coverage on travel along coarse woody debris by eastern chipmunks (Tamias striatus). Am Midl Nat 150:151–157
Acknowledgments
This study has been carried out within the project ‘RISELV.ITALIA’ (Task. 4.1) financed by the Ministry of Agricultural, Food and Forestry Policies. The authors wish to thank Stefano Morelli for helping in the data collection and the support in the hemispherical photographs processing.
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Communicated by C. Ammer.
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Paletto, A., Tosi, V. Forest canopy cover and canopy closure: comparison of assessment techniques. Eur J Forest Res 128, 265–272 (2009). https://doi.org/10.1007/s10342-009-0262-x
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DOI: https://doi.org/10.1007/s10342-009-0262-x