Lab 8. Photointerpretation of (Ontario Boreal) Tree Species

Transcription

1 Lab 8 Photointerpretation of (Ontario Boreal) Tree Species Tomislav Sapic GIS Technologist Faculty of Natural Resources Management Lakehead University

2 Suggested Approach to Learning Photo- Interpreting Tree Species Two books will be available as additional resources in learning photo interpretation: -Photographic Interpretation of Tree Species in Ontario, by Zsilinszky, V. G., 1963, Department of Lands and Forests, Government of Ontario - Mostly small-scale photography samples -Recognition of Tree Species on Aerial Photographs, by L. Sayn Wittgenstein, 1978, Canadian Forest Service. - Includes large-, medium-, and small-scale photography samples. Since it is often difficult to right away see described characteristics on small scale (e.g. 1:20,000) photos, it might be easier to first observe crown characteristics on large- and medium-scale (1:300 1:5,000) photos and then try to apply this knowledge and typical canopy characteristics in photointerpreting small-scale photos.

3 Introduction to Photo-interpretation of Tree Species Photographic interpretation is the act of examining photographic images for the purpose of identifying objects and judging their significance. Tree species are photointerpreted for different reasons, the main one being to create a forest resource inventory (FRI). FRI is usually created for large areas, most often for forest management units. Features that assist in tree species, including FRI, photointerpretation Characteristics to look for when interpreting: - Field data - Knowledge of the area, its management history - Knowledge of species distribution - Exaggerated vertical scale - Radial displacement - Texture - Pattern - Tone - Shadow - Shape Above all, tree species photointerpretation requires practice over time, to gradually build visual cues and train oneself to detect tonal, textural and pattern nuances.

4 Tree Species Covered through Photointerpretation Jack pine White spruce Black spruce Balsam fir White cedar Larch White pine Red pine Poplar/Aspen White birch Black ash

5 Spec. Occurrence Crown Canopy Similar Looking Species Jack pine - Variety of sites. - Pure stand on coarse sandy flats, association with black spruce on finer textured soil. - On dry sites, such as ridges and sand-flats, in association with red and white pine, aspen and white birch. - On fresh sites scattered with aspen, white birch, and black spruce. In closed stands small, pointed; in open very variable - Even texture and density, smoothly fuzzy texture. - Very old and open grown jack pine have an irregular shape but maintain fuzzy appearance. Sometimes can be confused with red or white pine. myccr.com/p hpbbforum/v iewtopic.php?p=279844

6 Spec. Occurrence Crown Canopy Similar Looking Species White pine - Variety of sites, pure stands or mixed associations. - On dry sites, such as sandy ridges and outwash plains, in association with red and jack pine. - On fresh sites and rich loam, where it reaches the greatest size, in association with hemlock, yellow birch, white spruce, and balsam fir. - Starshaped outline in vertical view - Its light and slender needles produce light tone on photos - Sometimes difficult to distinguish from red pine and hemlock. - Dead hardwoods with naked branches can form a star-shaped image, their crowns are, however, very open. nnesotawoods.um n.edu/2007/04/mi nnesotas-easternwhite-pine-foresttype/

7 Spec. Occurrence Crown Canopy Similar Looking Species Red pine -Found on variety of sites, commonly on upper slopes or ridges; also grows on dry, medium to coarse sandy plains. - In pure stands or in association with white pine and jack pine or with intolerant hardwood species, aspen and white birch. - Large, symmetrical, with a pointed oval or triangular profile -The stand pattern is honeycombed and the profile is saw-toothed. -Can be confused with white pine and white birch: - Darker than white pine, - Pointed crown as opposed to rounded up white birch s crown. ed_pine.ht m w.atthecre ation.com /WOODS/ HERBS.WO ODS.html

8 Schematic comparison of tree profiles and vertical views of white and red pine. Red pine honeycomb stand pattern and saw-toothed stand profile

9 Spec. Occurrence Crown Canopy Similar Looking Species White spruce - Grows best on well-drained fresh soils, where it is found in the mixture with aspen, white birch, and scattered balsam fir and black spruce. - In North. Ontario usually found on better-drained sites, including river-banks or lake shores. -Conical and sometimes very large; high density of shadows -It appears dark on the black & white photos. -Similar to black spruce, balsam fir, and cedar when mixed in the stands. - The crown is more irregular than that of balsam fir ctsheet/38#diapos

10 Spec. Occurrence Crown Canopy Similar Looking Species Black spruce - Pure stands on the lower elevations, swamps and muskegs. - In the northern boreal, a common uplands species on all soils, in pure stands or associated with jack pine and aspen -Very slender with pointed tops. - Cylindrical with a clumped top in older trees. - In pure stands, regular in pattern and with even height or changing gradually with the quality of the site. - White spruce, balsam fir, and cedar, when mixed in.

11 Spec. Occurrence Crown Canopy Similar Looking Species Balsam fir - Grows best on moist lower slopes, appears on a wide range of sites from swamp edges to dry uplands. - Found in mixture with jack pine, white and black spruce, white birch, and aspen. - Very symmetrical; the top is sharply pointed needle-like. - When dominant, erratic changes in heights producing irregular stand pattern. - White spruce, black spruce, cedar. - Individual branches are less prominent than in white spruce.

12 Spec. Occurrence Crown Canopy Similar Looking Species White cedar - Grows in swamps, around lakes and rivers, but may also occur on fresh hillsides and on dry ridges. - In pure stands or in mixed stands with Bf, Sb, Sw, La, Ab. - Dense and ovally conical. - When in groves, many trees lean and crisscross, which is often visible on photos. - In swamps, looses its characteristic form and becomes narrow, ovally conical or cylindrical, similar to black spruce only white cedar has a more open canopy. lowers/trees_and_shrubs/conifers/wh ite%20cedar/ %20nort hern%20white%20cedar%20%28thuja %20occidentalis%29%20tree%20- %20Manitoulin.JPG /05/cedar-swamps-and-deer.html dar_n.htm

13 Spec. Occurrence Crown Canopy Larch -Found in swamps, with Sb and Bf and on fresh sites with Po, Bw, Pw, and Pj. - Cone shaped, narrowly pyramidal in dense stands - Deciduous foliage appears very light on the photos. Similar Looking Species - Can be confused with aspen on black & white photos because the light green foliage may show an empty white spot radial displacement helps in seeing larch s outline.

14 Comparison of stand profile of white spruce, black spruce, balsam fir, and cedar.

15 Species Occurrence Crown Canopy Similar Looking Species Aspen - Very intolerant species that regenerates rapidly on burnt or logged areas. - Grows in association with white birch, balsam poplar, white and jack pine. - Rounded and open, very fine texture and light photographic tone. - Secondary branches and twigs are whitish grey. - In pure stands regular stand pattern at all ages. - In immature and mature stands often some space between crowns. -Sometimes similar to black ash, but the regular crown of aspen is denser than the irregular crown of black ash. - Might be confused with white birch aspen has larger crowns. raphs_snow_and_ice/pictures_snow_and_ice_w asatch_range.htm

16 Species Occurrence Crown Canopy Similar Looking Species White birch - Found in pure and mixed stands. - Associated with jack pine, poplar, white and black spruce. - Grows from rootsuckers in new burns. -Top conical with a rounded tip. - Crowns narrow in young trees, become wider in older trees. - Secondary branches and twigs are reddish-brown - More closed and denser than aspen s ; darker in tone. -Very similar to aspen in very young and overmature stands. - Only darker colour separates < 20 yr stands from aspen of same age. - In leafless conditions, reddish-brown secondary branches and twigs of white birch help separate it from aspen which has white branches all over. s/broadleaf_genera/species /birch_spp.htm n.org/rfm32

17 Schematic comparison of white birch and aspen stand pattern in horizontal and vertical views.

18 Species Occurrence Crown Similar Looking Species Black ash - Wet sites, bottomlands, swamps, stream edges and dried up beaver ponds. - Occasionally in pure stands and in association with black spruce, balsam fir, larch and white cedar. - Irregular, narrow, very open. - Light and fuzzy, almost transparent on the poor, very wet sites. - The space between the crowns makes black ash stands similar to aspen but the irregular shape of black ash crowns separates them from spherical and regular aspen crowns. xinus-comparison-chart/