Aspen and Oak Community Response to Restoration. Bobette Jones Coye Burnett

Transcription

1 Aspen and Oak Community Response to Restoration Bobette Jones Coye Burnett

2 Shade intolerant Aspen Life History Clonal: relies on vegetative reproduction between episodic seeding event Disturbance dependent: releases apical dominance/ creates establishment sites for seeds

3 Ecological Importance Landscape heterogeneity Biodiversity: Abundance and diversity of plants, birds, and inverts are greater in aspen stands than surrounding conifers Provide: higher forage quality as well important habitat structure for birds and mammals Water yields: aspen communities have less intercept and a lower duration of transpiration compared to conifer communities

4 Kuhn et al associated aspen-meadow-conifer forest sites. Aspen with <20% conifer cover. 2.5 a (1.54) a (1.63) Shannon-Weiner Diversity b (0.64) Aspen Conifer Meadow Community Type p <

5 Baseline monitoring Risk Rating Summary, Live Stands Only ( , N=700 stands; 3,805 acres) Stands 17% Mod 40% High 4% Low 39% High+ Risk Factors % Conifer encroachment 96 Excessive browse 54

6 Treatments Mechanical Thinning Aspen regeneration Soil moisture Stream attributes Fencing Aspen regeneration Grazing strategies

7 Results Effect of conifer removal on aspen density departure from control aspen number post treatment year None (Tot) Cut (Tot) None (SC1) Cut (SC1) None (SC2) Cut (SC2) None (SC3) Cut (SC3)

8 Results

9 Results

10 Results No adverse impact to in-stream or riparian habitat detected Collaborative Project (UCD) >60% of samples <0.05 ppm for NO 3 -N, NH 4 -N, PO 4 -P. Mean TSS < 15 ppm. No significant change in stream temperature Macroinvertabrates no detection of species tolerant of poor water quality No soil compaction

11 d r y kpa Soil Moisture Availability control aspen 2009 control aspen 2010 encroached meadow 2009 encroached meadow 2010 treated aspen 2009 treated aspen 2010 untreated aspen 2009 untreated aspen 2010 w e t Julian Day

12 Herbivory species and intensity deer livestock both percent of stands intense moderate light Intensity of browse

13 Wildlife Types of Fencing Livestock

14 Seasonal utilization by forage type utilization (%) Early Mid Late Early Mid Late Season aspen herbaceous meadow herbaceous aspen regeneration

15 Conclusion Lessons learned through monitoring Mechanically removing conifers has been a successful treatment to enhance aspen regeneration Aspen can be treated in riparian areas using responsible logging practices without adverse effects to stream attributes Management opportunities exist as an alternative for fencing in aspen stands with excessive cattle browsing

16 Shade intolerant Oak Restoration Reproduces vegetative (stump sprouting) and seeding Disturbance dependent

17 Landscape heterogeneity Structural Diversity: cavities, snags, and dead branches Ecological Importance Provide: acorns and oak mistletoe for a variety of wildlife species (deer, gray squirrels, turkey, and birds)

18 Treatments Mechanical Thinning Forest structure Oak regeneration Herbaceous and shrub understory Under-burning Herbaceous understory Oak regeneration Shrub cover

19 Study Area and Design Four treatments no-treatment (7), thin (23), thin and spring burn (3), thin and fall burn (2) Data collected prior to treatment, and 3 and 6 years post treatment Thin and burn treatments have a small sample size Treatments implemented in different years

20 Results Significant reduction in basal area for all treatments Basal Area Control Thin TSB TFB sq ft/ac post-trt year

21 Oak Response 0.18 Oak Canopy Cover 1 st year post treatment percent Control Thin TSB TFB 6 th year post treatment Oak Basal Area ft 2 /ac Control Thin TSB TFB Treatment

22 Results - thin pre-treatment year post treatment years post treatment 2011

23 Results thin and burn pre treatment st year post burn rd year post burn 2011

24 density (st/ac) density (st/ac) Results Successful black oak regeneration following treatment Basal Sprout Density Control Thin TFB TSB Trunk Sprout Density treatment year

25 stems/ac Results Successful black oak regeneration following thinning and fall burn oak seedlings B con thin tsp tfb 5 0 A year post treatment

26 Results - understory Pre-treatment 3 rd year post burn percent percent perennial graminoids shrub year post treatment con thin tsp tfb con thin tsp tfb

27 Conclusion Lessons learned through monitoring Oak vigor and regeneration increased following treatments Cutting black oak trees can stimulate stump sprouting but we do not recommend cutting oak in young stand especially if treatments includes burning Perennial grasses significantly increased in following thinning and burning. Conifer removal using thinning and burning is required to promote, enhance, and sustain the ecological value of these hardwood communities.

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