CLBMON-10 Kinbasket Reservoir Inventory of Vegetation Resources. Annual Report–2016
Author: V.C. Hawkes, P. Gibeau
This study provides an assessment of the effectiveness of the current operating regime at maintaining the existing riparian and wetland vegetation communities and associated ecosystems at the landscape scale.
Species Richness and Diversity:
– increased with elevation;
– increased with increasing organic matter;
– were positively correlated with an increase in GDDs in August;
– increased with increasing number of GDDs in May and September;
-varied by landscape unit (no discernible patterns);
– decreased over time (years);
– decreased as slope increased; and
– decreased when reservoir elevations are high in September (deep water).
Spatial Extent of Vegetation:
– increased (slightly) with time
– increased with high water in September;
– varied relative to vegetation community;
– was lower when GDDs were lower in May, June, July, and August; and
– decreased with increasing water depth in July.
Since 2007, the tendency has been to fill Kinbasket Reservoir earlier in the growing season and maintain higher elevations for longer into the year. This type of operation, coupled with an increased frequency of filling or surcharging the reservoir will likely result in a further reduction in species richness and diversity in communities situated in the upper elevation bands of the drawdown zone (i.e., those > 748 m ASL).The communities situated in the lower and mid elevation bands (i.e., < 748 m ASL) appear to have adapted to varying water depth, timing of inundation, and duration of inundation (i.e., varying wet and dry stress), and as such, have adapted to the way the reservoir has been operated since 1976 ( ). Although changes in these communities’ spatial extent, structure, and composition are expected, the magnitude of changes is anticipated to be small compared to changes that are likely to occur at elevations >748 m ASL if operations continue as they have.
At the current rate of occurrence of full pool to near full pool events, many of the woody stemmed species are unlikely to remain or become established at the upper elevations, resulting in long-term changes to the communities occupying those elevation bands. Because the current operating regime of the reservoir includes irregular full pool events, communities in the upper elevations are not likely to ever find equilibrium, because they will be trying to adapt to variable water depth and duration of inundation on an annual or semi-annual basis. However, with successive years of non-filling events (i.e., 2015 and 2016), there is evidence that several species, including herbs, grasses, and more importantly, woody stemmed species of willow and black cottonwood are establishing on ground that would normally be inundated in the fall (September). These patterns of colonization are consistent with the results CLBMON-10 and the effects of reservoir inundation on plant establishment vegetation community development. A reduction in the frequency, timing, duration, and depth of inundation will contribute to an increase in the cover and extent of vegetation in the drawdown zone Kinbasket Reservoir with the biggest changes occurring at higher elevations (>750 m ASL), on organic and mineral soils, and in areas devoid of wood debris.
Species Richness and Diversity:
– increased with elevation;
– increased with increasing organic matter;
– were positively correlated with an increase in GDDs in August;
– increased with increasing number of GDDs in May and September;
-varied by landscape unit (no discernible patterns);
– decreased over time (years);
– decreased as slope increased; and
– decreased when reservoir elevations are high in September (deep water).
Spatial Extent of Vegetation:
– increased (slightly) with time
– increased with high water in September;
– varied relative to vegetation community;
– was lower when GDDs were lower in May, June, July, and August; and
– decreased with increasing water depth in July.
Since 2007, the tendency has been to fill Kinbasket Reservoir earlier in the growing season and maintain higher elevations for longer into the year. This type of operation, coupled with an increased frequency of filling or surcharging the reservoir will likely result in a further reduction in species richness and diversity in communities situated in the upper elevation bands of the drawdown zone (i.e., those > 748 m ASL).The communities situated in the lower and mid elevation bands (i.e., < 748 m ASL) appear to have adapted to varying water depth, timing of inundation, and duration of inundation (i.e., varying wet and dry stress), and as such, have adapted to the way the reservoir has been operated since 1976 ( ). Although changes in these communities’ spatial extent, structure, and composition are expected, the magnitude of changes is anticipated to be small compared to changes that are likely to occur at elevations >748 m ASL if operations continue as they have.
At the current rate of occurrence of full pool to near full pool events, many of the woody stemmed species are unlikely to remain or become established at the upper elevations, resulting in long-term changes to the communities occupying those elevation bands. Because the current operating regime of the reservoir includes irregular full pool events, communities in the upper elevations are not likely to ever find equilibrium, because they will be trying to adapt to variable water depth and duration of inundation on an annual or semi-annual basis. However, with successive years of non-filling events (i.e., 2015 and 2016), there is evidence that several species, including herbs, grasses, and more importantly, woody stemmed species of willow and black cottonwood are establishing on ground that would normally be inundated in the fall (September). These patterns of colonization are consistent with the results CLBMON-10 and the effects of reservoir inundation on plant establishment vegetation community development. A reduction in the frequency, timing, duration, and depth of inundation will contribute to an increase in the cover and extent of vegetation in the drawdown zone Kinbasket Reservoir with the biggest changes occurring at higher elevations (>750 m ASL), on organic and mineral soils, and in areas devoid of wood debris.
Resources Data:
Name: CLBMON-10-YR6-2017-03-01
Format: PDF
URL: https://www.bchydro.com/content/dam/BCHydro/customer-portal/documents/corporate/environment-sustainability/water-use-planning/southern-interior/clbmon-10-yr6-2017-03-01.pdf
Additional Info
Study Years: 2007, 2008, 2010, 2012, 2014, 2016
Published: 2017
CLBMON-10 Kinbasket Reservoir Inventory of Vegetation Resources. Annual Report–2016
Author: V.C. Hawkes, P. Gibeau
Tags: Erosion, Kinbasket Reservoir, Monitoring Recommendations, Operational Recommendations, Reservoir Operations, Restoration Recommendations, Species Diversity, Species Richness, Vegetation, Vegetation Community, Water Level, Woody Debris
This study provides an assessment of the effectiveness of the current operating regime at maintaining the existing riparian and wetland vegetation communities and associated ecosystems at the landscape scale.
Summary
Species Richness and Diversity:
– increased with elevation;
– increased with increasing organic matter;
– were positively correlated with an increase in GDDs in August;
– increased with increasing number of GDDs in May and September;
-varied by landscape unit (no discernible patterns);
– decreased over time (years);
– decreased as slope increased; and
– decreased when reservoir elevations are high in September (deep water).
Spatial Extent of Vegetation:
– increased (slightly) with time
– increased with high water in September;
– varied relative to vegetation community;
– was lower when GDDs were lower in May, June, July, and August; and
– decreased with increasing water depth in July.
Since 2007, the tendency has been to fill Kinbasket Reservoir earlier in the growing season and maintain higher elevations for longer into the year. This type of operation, coupled with an increased frequency of filling or surcharging the reservoir will likely result in a further reduction in species richness and diversity in communities situated in the upper elevation bands of the drawdown zone (i.e., those > 748 m ASL).The communities situated in the lower and mid elevation bands (i.e., < 748 m ASL) appear to have adapted to varying water depth, timing of inundation, and duration of inundation (i.e., varying wet and dry stress), and as such, have adapted to the way the reservoir has been operated since 1976 ( ). Although changes in these communities’ spatial extent, structure, and composition are expected, the magnitude of changes is anticipated to be small compared to changes that are likely to occur at elevations >748 m ASL if operations continue as they have.
At the current rate of occurrence of full pool to near full pool events, many of the woody stemmed species are unlikely to remain or become established at the upper elevations, resulting in long-term changes to the communities occupying those elevation bands. Because the current operating regime of the reservoir includes irregular full pool events, communities in the upper elevations are not likely to ever find equilibrium, because they will be trying to adapt to variable water depth and duration of inundation on an annual or semi-annual basis. However, with successive years of non-filling events (i.e., 2015 and 2016), there is evidence that several species, including herbs, grasses, and more importantly, woody stemmed species of willow and black cottonwood are establishing on ground that would normally be inundated in the fall (September). These patterns of colonization are consistent with the results CLBMON-10 and the effects of reservoir inundation on plant establishment vegetation community development. A reduction in the frequency, timing, duration, and depth of inundation will contribute to an increase in the cover and extent of vegetation in the drawdown zone Kinbasket Reservoir with the biggest changes occurring at higher elevations (>750 m ASL), on organic and mineral soils, and in areas devoid of wood debris.