Impact of Swiss Needle Cast on Stand Growth and a Synthesis of Silvicultural Treatments for Mitigation

Transcription

1 Impact of Swiss Needle Cast on Stand Growth and a Synthesis of Silvicultural Treatments for Mitigation Doug Maguire & Doug Mainwaring College of Forestry Oregon State University

2 Growth impacts and silvicultural mitigation Growth impacts (Doug Maguire) Growth and mortality Foliage dynamics and measures of SNC severity Soil and foliar chemistry Silvicultural mitigation (Doug Mainwaring) Thinning effects Fertilization Fungicides

3 Growth impacts 1) What is the growth impact of SNC? 2) Does SNC accelerate Douglas-fir mortality? 3) How can we rate SNC severity? 4) Do stands recover from SNC? Does disease severity fluctuate? 5) What tools are available for estimating SNC growth impacts? 6) Are there predisposing conditions that suggest mitigation measures?

4 Growth impacts and silvicultural mitigation What is the growth impact of SNC? Does SNC accelerate Douglas-fir mortality? How can we rate SNC severity? Do stands recover from SNC? Does disease severity fluctuate? What tools are available for estimating SNC growth impacts? Are there predisposing conditions that suggest mitigation measures?

5 Growth Impact of Swiss needle cast Objectives 1) To establish the magnitude of growth losses resulting from varying severity of Swiss needle cast 2) To identify tree and/or foliage attributes that can serve as indices of SNC severity and corresponding growth losses

6 Growth Impact of Swiss needle cast Objectives (cont d) 3) To develop quantitative links among attributes monitored in aerial surveys, plantation surveys, and intensively measured growth plots 4) To monitor symptom severity and growth losses over time

7 SNCC Growth Impact Study transect A plot area = 0.2 ac point 4 66 ft B Retrospective vs. Permanent plots 66 ft point 5 D 93.3 ft C

8 TILLAM Lincoln # City # Astoria COL U MBIA R COLUM BIA R Astoria COLUMBIA R WALLO O CLATSKAN KLA SKANINE R, S F K SKEE R IE R Y O UNGS R LE W Seaside # K R Tillamook # Newport # # Waldport IS AND C LAR # Corvallis Forest # Grove # Salem # Albany # Columbia Cit # St. Helens NEC ANICUM R NEHALE M R, E FK SALMON B ER RY R NELAHEM R, N FK NEH ALE M R 76 Growth impact plots MIA MI R Portlan # WILLAMETTE W ILSON R, S FK T UALATIN R WILSO N R L I TLE N FK WILSON R KILCHIS R R TRASK R, E FK S F K TRASK R TRASK R, N FK OOK R 90% Douglas-fir yrs old N ORTH YAMHILL R NG R ILL R YAM H NESTUCCA R THR EE RIV E RS PUDDI LL R SOUTH YAM HI MO LITTLE PUDDING R LITTLE NESTUCCA R TA WILLAMETT E R SILETZ R L ITTLE LUCKIAMUTE R 22 Pre-commercial thinning plot sets LITTLE N LUCKIAMU TE R SANTIAM R S SANTIAM R CALAPOOIA R Y A QUINA R R O ARING R TUM TUM R Newport strial Portland MARY'S R MIDD LE S ALS EA R, N FK A R ALSE TOM R LONG A LSEA R

9 SNCC Growth Impact Study Dbh on all trees >1.37m in height Tagged all trees with dbh>6cm ( ) 40-tree height sample for Douglas-fir SNC ratings on 10 dominant or codominant DF trees per plot ( ): foliage retention color crown density crown transparency

10 Growth Impact Study Remeasurement schedule = SNC rating = SNC sample branch Foliage-soil sampling = growth measurement Phase 1 & 2 Phase 3 install Phase 3 remeasure Phase 3 remeasure Phase 3 remeasure Phase 3 remeasure

11 Net periodic annual increment over year of growth 500 Plot trends over time Net periodic annual increment (ft 3 ac -1 yr -1 ) Year

12 Net periodic annual increment over breast height age 500 Plot trends over time Net periodic annual increment (ft 3 ac -1 yr -1 ) Breast height age (years

13 Predicted growth losses for successive growth periods Growth period

14 Where Comprehensive dataset and model Douglas-fir stocking Site quality ln(pai NET ) = β 0 + β 1 ln(ba DF ) + β 2 ln(si) + β 3 ln(a)+ β 4 ln(fr-0.5) + ε Stand age SNC severity PAI NET = Net periodic annual increment (m 3 ha -1 yr -1 ) BA DF = Initial Douglas-fir basal area (m 2 ha -1 ) SI = Bruce s site index (m at 50 years) A = Plot average breast height age (years) FR = Plot average foliage retention (years) β k = Parameters estimated from the data ε = Error term with variance-covariance matrix having compound symmetry for observations within a plot over time

15 ln(pai NET ) = β 0 + β 1 ln(ba DF ) + β 2 ln(si) + β 3 ln(a)+ β 4 ln(fr-0.5) + ε Parameter Parameter estimate Standard error β β β β β

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17 Average growth loss by initial foliage retention, No threshold

18 Growth impacts and silvicultural mitigation What is the growth impact of SNC? Does SNC accelerate Douglas-fir mortality? How can we rate SNC severity? Do stands recover from SNC? Does disease severity fluctuate? What tools are available for estimating SNC growth impacts? Are there predisposing conditions that suggest mitigation measures?

19 Where Foliage retention (SNC) does not influence Douglas-fir mortality rate. sin -1 ( pmort) = β 0 + β 1 ln(ba DF ) + β 2 BA OC + β 3 BA HARD + ε pmort = mortality as proportion of initial cubic volume BA DF = Initial Douglas-fir basal area (m 2 ha -1 ) BA OC = Initial basal area in other conifers (m 2 ha -1 ) BA HARD = Initial basal area in hardwoods (m 2 ha -1 ) β k = Parameters estimated from the data ε = Error term with variance-covariance matrix having compound symmetry for observations within a plot over time

20 sin -1 ( pmort) = β 0 + β 1 ln(ba DF ) + β 2 BA OC + β 3 BA HARD + ε Parameter Parameter estimate Standard error β β β β

21 Periodic annual Douglas-fir mortality

22 Growth impacts and silvicultural mitigation What is the growth impact of SNC? Does SNC accelerate Douglas-fir mortality? How can we rate SNC severity? Do stands recover from SNC? Does disease severity fluctuate? What tools are available for estimating SNC growth impacts? Are there predisposing conditions that suggest mitigation measures?

23 SNC severity - Foliage retention (yrs)

24 DYNAMIC EQUILIBRIUM (with tree growth or under defoliation) Leaf area Sapwood area

25 SAME LIVE CROWN LENGTHS Low leaf area per unit crown length Relatively small sapwood area at crown base High leaf area per unit crown length Relatively large sapwood area at crown base

26 SAME LIVE CROWN LENGTHS Dense crowns Sparse crowns Large crown length to sapwood area ratio Small crown length to sapwood area ratio

27 Cubic volume growth loss by foliage retention and crown sparseness 0-20% 20-40% 40-60% 60-80% Crown sparseness (CL:SA in cm/cm 2 ) Mean foliage retention (yrs)

28 How does foliage retention relate to foliage amount? Correlated with: Amount of foliage in different age classes (area under curves at right) Vertical distribution of foliage by age class Relative depth into the crown SNC Severity LOW HIGH Light SNC (a) 0.2 LOW 0.4 Current 1-yr 0.6 HIGH Severe (c) SNC yr (e) 3-yr (g) 4-yr (i) 5-yr 1-yr-old 2-yr-old 3-yr-old 4-yr-old and older SNC Severity (b) (d) (f) (h) (j) Proportion of foliage dry matter Total foliage dry matter (g)

29 Growth impacts and silvicultural mitigation What is the growth impact of SNC? Does SNC accelerate Douglas-fir mortality? How can we rate SNC severity? Do stands recover from SNC? Does disease severity fluctuate? What tools are available for estimating SNC growth impacts? Are there predisposing conditions that suggest mitigation measures?

30 Trend foliage retention for each GIS plot from Plot average foliage retention (years) ) Annual fluctuation 2) General level specific to plot (but lots of lines cross-> change in plot ranks) Year

31 Level of foliage retention among years, ordered plots Foliage retention in subsequent years Pattern IF relative SNC severity remained constant among plots, but annual average fluctuated Plots ordered by increasing 1997 foliage retention

32 In general: Plots of high SNC severity became slightly better, SNC; Plots with low SNC severity became slightly worse Foliage retention in subsequent year Light year Plots ordered by increasing 1997 foliage retention 4.0 Average year 4.0 Heavy year Foliage retention in subsequent year Plots ordered by increasing 1997 foliage retention Foliage retention in subsequent years Plots ordered by increasing 1997 foliage retention

33 Level of foliage retention among years, ordered plots 4.5 Foliage retention in subsequent years Average range in foliage retention for plot with a given initial retention in Plots ordered by increasing1997 retention

34 Foliage retention exhibits annual fluctuations, but all plots do not vary in same direction or amount each year. Plot rank in disease severity changes over time. 4 Foliage retention in subsequent years Increase in retention Decline in retention no change foliage retention

35 Growth impacts and silvicultural mitigation What is the growth impact of SNC? Does SNC accelerate Douglas-fir mortality? How can we rate SNC severity? Do stands recover from SNC? Does disease severity fluctuate? What tools are available for estimating SNC growth impacts? Are there predisposing conditions that suggest mitigation measures?

36 Average growth loss by initial foliage retention,

37 Cubic volume growth loss by foliage retention and crown sparseness 0-20% 20-40% 40-60% 60-80% Crown sparseness (CL:SA in cm/cm 2 ) Mean foliage retention (yrs)

38 Stand Growth Assessment Tool

39 Stand Growth Assessment Tool Measured stand growth Expected stand growth Diagnostic: - Severity of SNC - Relative priority for treatment

40 Comparison of observed PAIs to ORGANON predictions 150 Observed-Predicted Foliage retention (yrs) Growth does not meet expectation under severe SNC

41 Growth multiplier for diameter and height growth in the SMC variant of ORGANON. Diameter: 1-exp(0.5952FR ) Height: 1-exp(1.0021FR )

42 Growth impacts and silvicultural mitigation What is the growth impact of SNC? Does SNC accelerate Douglas-fir mortality? How can we rate SNC severity? Do stands recover from SNC? Does disease severity fluctuate? What tools are available for estimating SNC growth impacts? Are there predisposing conditions that suggest mitigation measures?

43 Soil and Foliar Chemistry 25 sites, half at each SNC extreme, early 2000 Soil cores located relative to 5 random SNCrated trees: tree Random distance and azimuth from tree soil core Top 10 cm of mineral soil

44 Sampling for foliar chemistry 5-YR-OLD SAMPLE BRANCH (5TH WHORL DOWN FROM TREE TIP) SAMPLE BRANCH

45 Sampling for foliar chemistry Tip of 5-yr-old sample branch 1999 foliage sample

46 Needle retention (yrs) Needle Retention as a Function of Needle N Concentration Needle nitrogen (% dry wt)

47 Needle retention by foliar N and Ca yrs 3-4 yrs 2-3 yrs 1-2 yrs Foliar Ca (%) Foliar N (%)

48 Growth Impact of Swiss needle cast S and NO 3 have consistently negative relationship to foliage retention Ca has consistently positive relationship to foliage retention Foliar S, foliar (or soil) Ca, and soil NO 3 explain 91% of the variation in foliage retention

49 One hypothesis Alder N- fixation Coupled leaching of Ca and NO 3 (Perakis et al. 2006) Relative excess of N Storage as free amino acids Substrate for Phaeocryptopus gaeumannii (El Hajj et al. 2004) Ca++ NO 3 -

50 Can fertilization ameliorate SNC? (Main Doug has the rest of the story... )

51 Climatic influences

52 Climatic influences on foliage retention Geographic variation: Risk defined by local climatic factors (Rosso, Hansen, Coop, Stone, Latta) Annual variation: Driven by long-term site average and annual fluctuations in climatic conditions (Zhao) Lagged climatic variables: Winter temperature Spring/summer wetness Late summer heat Dynamics of individual needle cohorts that contribute to foliage retention (Zhao)

53 Foliage retention by age class or cohort 9 -> % 8 -> 80-89% > 0-9%

54 Foliage retention by age class or cohort 1993 cohort 1994 cohort 1995 cohort 1996 cohort 1997 cohort 1998 cohort 2002 cohort 2001 cohort 2000 cohort 1999 cohort

55 System of equations Foliage retention by age class as function of climatic variables with differing lag times FR1 t = β 10 + β 11 SW t-1 + β 12 WT t + β 13 SH t-1 + ε 1 FR2 t = β 20 + β 21 SW t-2 + β 22 WT t-1 + β 23 SH t-2 + ε 2 FR3 t = β 30 + β 31 SW t-3 + β 32 WT t-2 + β 33 SH t-3 + ε 3 FR4 t = β 40 + β 41 SW t-4 + β 42 WT t-3 + β 43 SH t-4 + ε 4 FRk t = Foliage retention of k-yr-old foliage at time t β k = Parameter to be estimated from the data SW t = Spring/summer wetness at time t WT t = Winter temperature at time t SH t-1 = Summer heat at time t ε 1 = Error term for equation k, assumed correlated with error term from other equations

56 Needle survivorship models Is the needle survival curve driven by conditions in year of formation only, or also subsequent years?

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58 Disease triangle environment: temperature precipitation fog nutrients pathogen: Phaeocryptopus gaeumannii host: Douglas-fir

59 Thanks... now on to Main Doug...

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61 Aaron Weiskittel M.S. Thesis (a) Severe SNC Low SNC Current Foliage age class Proportion of total foliage mass Proportion of foliage mass in each foliage age class

62 Cu e 3 Aaron Weiskittel M.S. Thesis 6000 (b) Current Foliage age class Total foliage mass Amount of foliage in each age class (g)

63 1.2 Foliage retention rank correlations Corrlation with base year Base year Year of observation

64 1.2 Foliage retention rank correlations Corrlation with base year Base year Year of since initial observation

65 Growth Impact of Swiss needle cast What is the range in SNC severity? 5 Foliage retention (yrs) graph of min, mean, max Year

66 % expected BA growth Maximum SNC "effect" on BA growth (lowest foliage retention in 1996) appr. 95% confidence envelope SNC significant after 1990 Mean 20 0 Year

67 Growth losses estimated from retrospective analysis 30 Cubic volume growth loss (%) foliage retention lower reliability Year

68 Basal area growth and weather trends % of expected BA growth temperature rainfall Year Mean needle retentio n Normalized summer rain and temp

69 Average growth loss for population of young Douglas-fir plantations 30 Cubic volume growth loss (%) % per year 95% confidence interval Year

70 Basal Basal area area growth (cm 2 ) Annual basal area growth for individual trees Plot 7 retx = Year

71 Plot 1 retx = Year Basal Basal area area growth (cm 2 )

72 Basal Basal area area growth (cm 2 ) Plots 1 and 7 retx = 3.65 retx = 1.43 Effects of stand density, age, site, SNC? Year

73 Sapwood conducts water to service foliage for transpiration. Sapwood cross-sectional area is proportional to foliage amount. crown base Heart wood core Sapwood shell crown base

74 Swiss needle cast growth impact Growth loss (%) Foliage retention (years)

75 Periodic annual Douglas-fir mortality

76 Needle survivorship models

77 Gross periodic annual increment over year of growth 500 Gross periodic annual increment (ft 3 ac -1 yr -1 ) Year

78 Gross periodic annual increment over breast height age 500 Gross periodic annual increment (ft 3 ac -1 yr -1 ) Breast height age (years)

79 Level of foliage retention among years, ordered plots 4 Foliage retention in subsequent years Increase in retention Decline in retention no change foliage retention

80 Level of foliage retention among years 4.5 Plot average foliage retention (years) Plot number