1. Dendrochronology – Analysis of annual rings in woody plants
Herb-chronology
Dendrochronology – Analysis of annual rings in woody plants
herbaceous!
Georg von Arx

2. Overview 1. What is herb-chronology? 2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

3. Dendrochronolgy vs. herb-chronology
Dendrochronology
Herb-chronology
Forbs Semi-shrubs Dwarf shrubs Shrubs Trees
Long-lived; perennating tissue mostly in above-ground stems
Short-lived; perennating tissue mostly in below-ground structures
Annual rings as proxies for past environmental conditions
Currently invading
Annual rings as proxies for past life
of individual plants

4. Phenology & anatomy of annual rings in perennial forbs
Secondary xylem
Semi ring-porous
Growing period: 1 2 3 4
Primary xylem
Currently invading

5. Sanguisorba minor

6. Herb-chronology: 1st year
The analysis of annual rings in the root xylem of perennial forbs
Measures:
Number of annual rings (→ plant age)
Width of annual rings (→ growth)
Vessel parameters (→ growth, water supply)
1st year
2nd year
3rd year
4th year
Sanguisorba minor

7. Overview 2. Methods in herb-chronology 1. What is herb-chronology?
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

8. How to get annual ring data
Agastache urticifolia
How to get annual ring data
Collecting roots
Thin cross-sections with sledge microtome
Staining of lignified structures (HCl/phloroglucinol)
Digital picture
On-screen analysis

9. Overview 3. Sample applications 1. What is herb-chronology?
2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

10. Population of Bunias orientalis (Ayent, Germany, 900 m asl)
Area: 1000 m2
Old fallow, unmanaged
In total individuals
Individuals are scattered

11. Comparison of population age structure
B. orientalis
Old fallow
Meadow 20 40 60 80
100
15 Indv./m 2 1 3 4 5 6 7 8 9 10
127 Indv./m
mown (1/yr)
Exponentially growing population 10 20 30 40 50
38 Indv./m 2
1995
Number of individuals [%] 10 20 30 40 50 1 2 3 4 5 6 7 8 9
36 Indv./m
Degenerating population
1997
Age [yrs.]
unmanaged
Dietz & Ullmann, Annals of Botany (1998)

12. Overview 3. Sample applications 1. What is herb-chronology?
2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

13. Invasion patterns Young cohorts Intermediate cohorts Old cohorts
Front invasion
Diffuse invasion
Number of individuals
Transect
Time
Adapted from Wilson & Lee, Functional Ecology (1989)

14. Spatial population dynamics → diffuse invasion
Lythrum salicaria,
Meadow (Michigan, USA)
Invasion
Age (yrs.)
No. of individuals
Dietz, Biological Invasions (2002)

15. Spatial population dynamics → front invasion
Shape of the population
Transect
10 m
Adventitious roots
Main roots
Age [yrs.]
Alter [Jahre]
Digitalis grandiflora
Position along transect [m]
Dietz, Biological Invasions (2002)

16. Overview 3. Sample applications 1. What is herb-chronology?
2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

17. Mean Enso Index and deviations in mean global temperature
Mean Enso Index (Enso – El Niño/Southern Oscillation)
Mean global temperature

18. Data structure USA Switzerland Set 1 Midwest ≤ 400 m asl 8 species
Davos/Alpstein
≥ 1400 m asl
3 species
Set 2
Oregon (NW)
≥ 1200 m asl
4 species
Swiss Alps
≥ 1900 m asl
1 species

19. Fluctuations in growth ring width
USA CH *
Set 1
Set 2
Set 1 & 2
Temperature
Precipitation
Snow cover
Dietz & von Arx, Ecology (2005)

20. Overview 3. Sample applications 1. What is herb-chronology?
2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

21. Environmental factors along an altitudinal gradient
Vegetation period
Temperature
Nutrients
[CO2]
Vegetation density
Temperature amplitude
Precipitation
Light
Intensity of factor
With increasing Altitude …
negative
positive
Altitude

22. Sample design Rudbeckia occidentalis (Asteraceae) - 1200-2050 m asl
Wallowa Mountains, NE-Oregon, USA
Sample design
Rudbeckia occidentalis (Asteraceae)
m asl
- 4 altitudinal levels
- 6-8 plants/level
Penstemon venustus (Scrophulariaceae)
m asl
- 5 altitudinal levels
- 6-9 plants/level
Lupinus laxiflorus (Fabaceae)
m asl
Wallowa Mountains, Oregon, USA

23. Rudbeckia occidentalis
Penstemon venustus
Lupinus laxiflorus

24. R. occidentalis
P. venustus
L. laxiflorus

25. Age, no. of shoots and mean ring width vs. altitude
von Arx et al., Ecology (2006)
Penstemon venustus
Lupinus laxiflorus
Rudbeckia occidentalis

26. Overview 3. Sample applications 1. What is herb-chronology?
2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

27. Growth trajectories vs. altitude
Penstemon venustus
Lupinus laxiflorus
Rudbeckia occidentalis
von Arx et al., Ecology (2006)

28. Conclusions from the altitudinal gradient-study
High altitude plants grow
- older
- slower
- larger
Shifts from linear to curvilinear growth trajectories towards higher altitudes
═►More conservative and constrained life history at higher
altitude

29. Overview Summary 1. What is herb-chronology?
2. Methods in herb-chronology
3. Sample applications
- Ex. 1: Comparison of population age structure
- Ex. 2: Spatial and temporal dynamics of populations
- Ex. 3: Short-term responses of individual annual rings
- Ex. 4: Responses of annual rings to environmental gradients
- Ex. 5: Analysis of life history
Summary

30. Summary
Herb-chronology is the analysis of annual rings in perennial forbs
Important measures are number and width of annual rings, and diameters of xylem vessels
Herb-chronology may be valuable in the following fields (e.g.):
Structure, spatial and temporal dynamics and comparison of populations
Influence of extreme events on growth
Influence of environmental gradients on life history

31. Acknowledgements Keep up-to-date with herb-chronology
Hansjörg Dietz  Peter J. Edwards  Jake M. Alexander  Regula Billeter  Daniela Csencsics  Silke Dietz  Sabine Güsewell  Moritz Kuhn  Kirk A. Moloney  Catherine Parks  Dieter Ramseier  Miriam Schädler  Fritz H. Schweingruber  Matthias Suter  Lea Wirth
Geobotanical Institute ETH  ETH  Swiss National Science Foundation
Keep up-to-date with herb-chronology

33. Roxas – Automated image analysis of annual rings in the roots of perennial forbs

34. ?
Penstemon venustus

36. Evaluated Species Pflanzenbilder Trifolium badium Penstemon venustus
© A. Mielnikow
Penstemon venustus
© G. von Arx
Sanguisorba minor
Erinus alpinus
Bunias orientalis
causses-cevennes.com

37. Penstemon venustus
Trifolium badium
Sanguisorba minor
Erinus alpinus
Bunias orientalis

38. 200 μm
Trifolium badium

39. 200 μm
Trifolium badium

40. 200 μm
Trifolium badium

41. Vessel extraction & identification of annual rings
All species
Vessels
Rings
Overall number
2379
189
Correctly identified
98%
95%
Pseudo-vessels or -rings
679 17
D = * 100
R – X R
D: deviation index
R: reference measurement
X: manual / automated measurement
D (%)
Bo Ea Pv Sm Tb *
D = 6.17
D = 4.41
Accuracy of ring width measurements

42. Additional Parameters produced by ROXAS
Ring area (vs. ring width)
Average & individual vessel size
Accumulated vessel area
Accumulated vessel area per ring area
(vessel area density)
Number of vessels per xylem area
B. orientalis
P. venustus
E. alpinus
Average vessel size (μm2)
475
342 70
Vessel area density (%)
4.0
12.5
5.4

43. Summary  Automated analysis is … More objective (reproducible)
More accurate
Faster
Easier
Additional parameters 
Automated analysis is …

45. The diversity of form and shape
Beauty lies in nature
The diversity of form and shape

46. The methuselah

47. The one-sided

48. The radiating 1

49. The beauty

50. The delicate

51. The radiating 2

55. Reaktion auf Standortfaktoren
Umweltveränderungen
Ontogenetisches Muster

56. Phylogenetische Variabilität in der Jahresringentwicklung
Asteraceae
Euphorbiaceae
Rosaceae
Zunehmende Variabilität des anatomischen Musters innerhalb der Familie
Fabaceae
Lamiaceae
Brassicaceae
Apiaceae
Caryophyllaceae
Deutlichere Abgrenzung der Zuwachsringe

57. Herbchronologische Eignung im Standortsgradienten
Anteil von Stauden mit klaren Jahresringen in der Hauptwurzel
subalpine Rasen
Ruderal-
standorte (ME)
Mediterrane Standorte
Wald, Feuchte
Wiese (ME)
Trocken-
rasen (ME)
saisonal,
kurze
Wuchs-
periode
hoch
TEMPERATURKLIMA
durchschnittlich
gering
gleich-
mässig
feucht
BODEN
trocken