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Table of Contents
Foreword
Preface
Glossary

Chapter 5: Vegetation

5.8: Riverine Gallery Forest on the East Side of Pelican Lake

This infrared photograph shows part of the east shore of Pelican Lake 1, a shallow lake on the floor of the Souris-Pembina spillway. Infrared photographs employ a false colour technique in which objects reflecting large amounts of infrared radiation—which the human eye cannot see—are imaged as red. Photo-synthesizing vegetation typically reflects large quantities of infrared so that live healthy vegetation is imaged as bright red.

Here, along the east wall of the spillway, riverine gallery forest, mainly aspen (Populus tremuloides) and bur oak (Quercus macrocarpa), shows up in bright-red tones with mottled texture 2. The scale of the photograph is large enough that rounded shadows thrown by individual trees can be identified 3. A clearing within the forest contains low-lying bushes that are imaged as pink 4. Rounded patches 5 suggest that these are creeping juniper (Juniperus horizontalis).

In the north, crops are growing in five fields 6. In the western-most of these it can be seen that the crop is growing well in some areas 7 but not so well in others 8. Three fields that have been left fallow 9 are imaged as dark green, but in the southernmost field weed growth results in a pink tinge 10.

The v-shaped projection into Pelican Lake 11 is one of several similar features located near the mouths of small streams. This point, known locally as Y point, has been used as a summer camp for over 100 years[i] and cottages have been built along the shore 12. A major problem for Pelican Lake as a recreational resource is that it is very shallow and has little through-flow of water. Contamination of the water leads to algae growth in the summer; the pink colouring on both sides of the point (13 and 14) are a result of this.

Figure 5.8: Riverine Gallery Forest on the East Side of Pelican Lake

Figure 5.8: Riverine Gallery Forest on the East Side of Pelican Lake

Figure 5.8

Vertical air photograph: colour infrared

Flight height: ; lens focal length:

Date:

Scale: 1:10,300 (approx.)

Location: Township 5; Range 16 WI

Map sheets: 1:250,000 62G Brandon

1:50,000 62G/5 Dunrea

Notes

[i] For details see Welsted, J. “The Ups and Downs and Ins and Outs of Pelican Lake: A Water Resource Dispute in Southwestern Manitoba.” Proceedings of the Prairie Division of the Canadian Association of Geographers, ed. M. R. Wilson, Saskatoon: University of Saskatchewan. 1993, 221-229.