1. Spatio-temporal patterns in plant populations in small landscape elements Patrick Endels Laboratory for Forest, Nature and Landscape Research, KULeuven Vital Decosterstraat 102 B-3000 Leuven, Belgium Tel +32(0)16.32.97.69 Fax +32(0)16.32.97.60

2. outline 1. research questions 2. data recording 3. data management 4. analysis of temporal changes 5. analysis of spatial patterns 6. further analyses 1 2 3 4 5 6

3.  Impact of different ‘management’ regimes on demographic parameters of populations in small landscape elements?  (Primula veris) vs. (Primula vulgaris)  barochory (Primula veris) vs. myrmecochory (Primula vulgaris) -> population dynamics & max. dispersal distance?  Impact of ‘management’ regimes on shape & tail of the dipsersal curve?  Relationship between dispersal distance & subsequent seedling/juvenile survival general research questions 1 2 3 4 5 6

4. data recording 1 2 3 4 5 6 Primula vulgarisPrimula veris

5. data recording 1 2 3 4 5 6 Primula vulgaris Primula vulgaris 13 populations 13 populations forest edges (n=3) vs. forest edges (n=3) vs. grazed parcel margins (n=4) vs. [1999-2002] grazed parcel margins (n=4) vs. [1999-2002] clearing of ditches & mowing (n=2) clearing of ditches & mowing (n=2) restoration of mowing regime (n=1) [1999-2003] restoration of mowing regime (n=1) [1999-2003] changes in adjacent land use (n=1) [1999-2002] changes in adjacent land use (n=1) [1999-2002]

6. data recording 1 2 3 4 5 6 Primula veris 16 populations 16 populations graft (Voeren) (n=4) vs. graft (Voeren) (n=4) vs. grazed parcel margins (n=4) vs. [2000-2002] grazed parcel margins (n=4) vs. [2000-2002] clearing of ditches & mowing (n=4) clearing of ditches & mowing (n=4) restoration of calcareous grassland (n=2) [1999-2001] restoration of calcareous grassland (n=2) [1999-2001] (Voeren) (Voeren)

7. data management 12 3 4 5 6 Life stage 1999 rosettes 1999 Life stage 2000 rosettes 2000 … Plant 1 fl. adult 5 n-fl. adult 10 Plant 2 seedling1juvenile1 Plant 3 juvenile1 Plant 4 n-fl. adult 1 fl. adult 2 Plant 5 seedling1 …

8. analysis of temporal changes 1 2 3 4 5 6 Stage classification = a combination of both reproductive and size criteria Seedlings: individuals developed directly after the germination of seeds, with cotyledons still present and often also one ‘normal’ leaf-pair. Juveniles: immature plants without cotyledons and with only one rosette of leaves. Juveniles can only be distinguished from vegetative adults with one rosette by means of their size: an individual is considered as an adult when its leaf size is comparable to flowering plants in the same population; if leaf size is significantly smaller then the individual is assigned to the juvenile category. Vegetative adults: non-flowering individuals without cotyledons, with one or more rosettes, often showing signs of overwintering leaves. Leaf size is comparable to generative adults which are growing under similar conditions. Reproductive adults: plants baring one ore more flowering stalks, having one or more rosettes and often showing signs of older, overwintering leaves. These flowering adults were divided into three size categories according to the number of rosettes.

9. analysis of temporal changes 1 2 3 4 5 6 SJNF A RA 1 RA 2 RA 3 -> Moloney (1986) vs. empirical approach

10. YEAR t+1 t+1 L 66 G 62 G 64 G 63 00 Repr Adult 3 L 56 L 55 G 54 G 53 G 52 G 51 Repr Adult 2 L 46 L 45 L 44 G 43 G 42 G 41 Repr Adult 1 L 36 L 35 L 34 L 33 G 32 G 31 NFAdult F6F6F6F6 F5F5F5F5 F4F4F4F40 L 22 G 21 juvenile F3F3F3F3 F2F2F2F2 F1F1F1F1000 seedling Repr Adult 3 (>3 roz.) Repr Adult 2 (2-3 roz.) Repr Adult 1 (1 roz.) NFAdultjuvenileseedling YEAR t 1 2 3 4 5 6 analysis of temporal changes n(t + 1) = A n(t)

11. analysis of temporal changes 1 2 3 4 5 6SymbolDefinitionDemographicinterpretationA a square matrix containing the coefficients that represent proportions of – mostly year-to-year – transitions between life stages. Projection matrix a ij the element in row i, collum j of the projection matrix A matrix element the dominant eigenvalue of A population growth rate  A  =  (the right eigenvector of A associated with ) stable stage distribution   A =   A =  (the left eigenvector of A associated with ) reproductivevalues s ij  /  a ij (the sensitivity of to changes in matrix element a ij ) sensitivity e ij a ij  /  a ij (the proportional sensitivity of to proportional changes in matrix element a ij ) elasticity  1 / 2 1 / 2 (ratio between the dominant & subdominant eigenvalue) damping ratio

12. 1 2 3 4 5 6 sensitivity analysis (Silvertown et al. 1992, 1996) Triangular plot of composite elasticity values for growth (G), statis (L) and fecundity (F) speciespopulations

13. 12 3 4 5 6 sites [P. vulgaris] forest edges grazed parcel margins ditch clearing (+mowing)

14. 1 2 3 4 5 6 population growth rates [P. vulgaris] repeated measures ANOVA: tests of within-subjects contrasts FP YEAR11.019< 0.05 YEAR * MANAGEMENT6.533< 0.05 tests of between-subjects effects FP MANAGEMENT6.5650< 0.05

15. sensitivity analysis [P. vulgaris] 12 3 4 5 6 mown/cleared forest edge grazed

16. 1 2 3 4 5 6 population growth rates [P. vulgaris] different mowing regimes ?

17. 1 2 3 4 5 6 sensitivity analysis [P. vulgaris]

18. 1 2 3 4 5 6 not mown mown 1 mown 2 sensitivity analysis [P. vulgaris]

19. 1 2 3 4 5 6 population growth rates [P. vulgaris] clearing (+mowing) of ditches

20. 1 2 3 4 5 6 sensitivity analysis [P. vulgaris]

21. 1 2 3 4 5 6

22. 1 2 3 4 5 6 population growth rates [P. vulgaris] changes in adjacent land use !

23. 1 2 3 4 5 6 sensitivity analysis [P. vulgaris]

24. 1 2 3 4 5 6 arable field grassland

25. 12 3 4 5 6 clearing / mowing grassland margins sites [P. veris] graft (Voeren)

26. 1 2 3 4 5 6 population growth rates [P. veris] repeated measures ANOVA:

27. sensitivity analysis [P. veris] 12 3 4 5 6 F L F GL

28. 1 2 3 4 5 6 conclusions temporal analysis [P. vulgaris & P. veris] - 1 P. vulgaris P. veris mown / cleared grazed forest edge mown / cleared grazedgraft λ: management effect? abababab λ: year effect? yesno Sensitivity analysis λ rel. dep. on fecundity λ higly dep. on survival adults intermed.λ rel. dep. on fecundity λ higly dep. on survival adults intermed.

29. 1 2 3 4 5 6 conclusions temporal analysis [P. vulgaris] - 2 (a) mowing regime - first year : effect of mowing once or twice a year ≅ - In the “long run”: only mowing twice a year (July & October) efficient to counter population senescence to lift λ above 1 (b) ditch clearing regime (& mowing of ditch bank) - large impact on population growth rate (depending on intensity) - temporarily higher mortality levels - compensated by higher seedling recruitment and survival c) changes in adjacent land use - grassland -> arable field: (1) effect on population growth rate and (2) populations more responsive to survival of veg. adults - population quickly recovers when the original land use is restored

30. 1 2 3 4 5 6 conclusions temporal analysis [P. vulgaris & P. veris] - 3 in general: - disturbances of any kind force populations into earlier stages of the successional G-L-F trajectory (Silvertown et al. 1996) - however, these more dynamic populations (i.e. more dependent on / responsive to fecundity and growth) are not necessarily associated with higher population growth rates ( ’s)

31. analysis of spatial patterns 1 2 3 4 5 6 calculation of dispersal distances dispersal curves for the two species for different management regimes -> tail (max. dispersal distance)?! dispersal distance and survival -> Janzen (1970)-Connell (1971) vs. Hubbell (1979)

32. 1 2 3 4 5 6 calculation of dispersal distances

33. 1 2 3 4 5 6 dispersal distance & management regime [P. vulgaris] max. = 1.04 m max. = 1.26 m max. = 0.61 m mean = 0.29 m mean = 0.25 m mean = 0.19 m max. = 2.12 m mean = 0.17 m max. = 0.54 m mean = 0.16 m max. = 2.45 m mean = 0.26 m max. = 2.62 m mean = 0.42 m max. = 3.89 m mean = 0.38 m max. = 1.89 m mean = 0.36 m a a a ab b b b c b

34. 12 3 4 5 6 dispersal distance & management regime [P. veris] max. = 0.57 m max. = 2.60 mmax. = 0.47 m max. = 5.49 m mean = 0.10 m mean = 0.15 m mean = 0.23 m mean = 0.25 m < P < 0.001 ≈ ? n.s

35. 1 2 3 4 5 6 P. vulgaris dispersal distance & survival Wald χ² = 44.285 n = 1720 P < 0.001

36. 1 2 3 4 5 6 P. vulgaris dispersal distance & survival dispersal distance Wald χ² = 4.425 n = 91; P = 0.035 Wald χ² = 0.065 n = 271; P = 0.798 Wald χ² = 53.200 n = 1344; P < 0.001

37. 1 2 3 4 5 6 dispersal distance & survival P. veris Wald χ² = 15.223 n = 2815 P < 0.001

38. 1 2 3 4 5 6 dispersal distance & survival P. veris dispersal distance Wald χ² = 7.141 n = 344; P = 0.008 Wald χ² = 16.137 n = 2438; P < 0.001

39. 1 2 3 4 5 6 spatial patterns: conclusions P. vulgaris P. veris management forest edge grazed mown / cleared grazed dispersal distance *********** seedling / juvenile survival **** (63 %) **** (62 %) *** (47 %) ** (19 %) * (8 %) dispersal (D) ~ survival (S) S ▲ if D ▲ herbivory / pathogens / intraspecific comp. ? n.s. S ▲ if D ▲ herbivory / pathogens / intraspecific comp. S ▲ if D ▲ herbivory ? S ▼ if D ▲ high disturbance regime ? J.-C. H.

40. further analyses (1) 1 2 3 4 5 6 temporal changes - relationship with reproductive output - comparison of population growth rate by randomization tests - LTRE (mowing regime P. vulgaris, management regime P. veris) - stochastic population modelling (Caswell 2001, Tuljapulkar & Caswell 1997)

41. spatial patterns - relationship between aggregation & dispersal distance (calculation of Ripley’s K & comparison between management regimes) - aggregation and flower morph types ? - ? ? ? incorporating plant performance - link with recruitment / population dynamics ? further analyses (2) 1 2 3 4 5 6