ANALYZING THE RESTORATION POTENTIAL OF COAST REDWOOD USING A CHRONOSEQUENCE OF NATURAL RECOVERY

Transcription

1 ANALYZING THE RESTORATION POTENTIAL OF COAST REDWOOD USING A CHRONOSEQUENCE OF NATURAL RECOVERY Will Russell 1, Kristin Michels 2, and Jeff Sinclair 1 1 San Jose State University, San Jose, CA, USA 2 University of Wisconsin, Madison, WI, USA

2 Unique Sequoia sempervirens forest characteristics Tallest trees in the world (379 ft). One of the most productive (high carbon storage potential). Relict genus going back to the Jurassic period. Provides unique and diverse habitat for associated species. Clonal reproductive strategy Atlas Tree Illustration by R. VanPelt

3 The Need for Restoration 95-97% OG lost Conversion of some second growth stands to functioning lateseral essential for the survival of the ecosystem. Corridors and connectivity Buffers of old growth preserves

4 Only 3-5 % of the original old-growth forest remains Research Question What are the patterns of recovery following timber harvest in the absence of post-harvest management? Challenges Extreme longevity limits real time analysis.

5 10 0 Max life span in Homo sapiens 2,500 Chronosequence Max life span Sequoia sempervirens Developmental sequence time static

6 Restoration Goals: Late Seral Characteristics Support natural successional processes Reduce tree density. Increase size structure spread. Enhance redwood dominance. Enhance associated understory species. Reduce exotic invasives. Increase structural characteristics.

7 Structural Complexity

8 Stages of forest recovery following major disturbance Oliver, 1981

9 Study Area - Big River State Park

10 Sampling Intensity 6 - age classes 3 - replicate sites in each age class 20 - randomly located 20-meter diameter sample plots per site = 360 total sample plots

11 Data Gathering Canopy Cover, slope, and aspect Diameter and species of all trees Percent cover and species of all understudy species.

12 Results Stand Reinitiation Simultaneous clonal sprouting throughout the stand

13 Density driven feedback Stand Reinitiation Stem Exclusion Why density is not an issue in coast redwoods? Clonal regeneration Shade tolerance Epicormic sprouting Self thinning

14 Self Thinning stems/ha OG ANOVA,P-value < Regression,P-value < 0.001, R2=0.271, OG (41-60 yrs)

15 Chronosequence on Six Age Classes 0-20 years years Photos courtesy of K. Hageseth

16 41-60 years years Photos courtesy of K. Hageseth

17 Old Growth 100+ years Photo courtesy of K. Hageseth

18 Size-class Analysis >5-24cm cm stems/ha cm cm cm >200cm OG size-class

19 Canopy Cover 88 Tree % OG age-class ANOVA,P-value < Regression,P-value < 0.001, R2=0.052, OG ( yrs)

20 Species Richness species/plot OG ANOVA,P-value < Regression,P-value < 0.002, R2=0.028, OG ( yrs)

21 Non-Native Species Cover % cover OG ANOVA,P-value < Regression,P-value < 0.002, R2=0.053, OG ( yrs)

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23 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

24 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

25 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

26 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

27 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

28 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

29 Lonicera hispidula, Whipplea modesta, Toxicodendron diversilobum Species Assemblages Trillium ovatum, Oxalis oregana, Viola sempervirens, Tiarella trifoliata, Calypso bulbosa

30 Redwood Associates Trillium ovatum Viola Sempervirens Calypso bulbosa

31 Redwood Associates 1.4 a 1.2 % cover Calypso bulbosa Trillium ovatum Viola sempervirens OG age-class Cabu (OG yrs), Trov (OG yrs), Vise (OG yrs)

32 Redwood Associates Iris douglasiana Tiarella trifoliata Achlys triphylla

33 Redwood Associate 1.6 b % cover Iris douglasiana Tiarella trifoliata Achlys triphylla OG age-class

34 Stand Reinitiation Stem Exclusion Understory Reinitiation Old-growth

35 Basal Area m 2 /haa OG ANOVA,P-value < Regression,P-value < 0.001, R2=0.603, OG (not achieved)

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37 Relative dominance (dbh) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% OG P. menziesii L. densiflorus S. sempervirens Artifact resulting from intentional preservation of redwood dominated stands?

38 Conclusions Chronosequence is an effective tool for analyzing natural recovery pattern in Coast Redwood

39 Questions? Photo courtesy of K. Hageseth