A patch-dynamics approach to savanna dynamics and woody plant encroachment - Insights from an arid savanna

Perspectives in Plant Ecology, Evolution and Systematics

Volumn 7, Issue 4, 2006, Pages 229-242

  Wiegand, Kerstin ^a,b,d   Saltz, David ^b,c   Ward, David ^b,e  

^a PRINCETON UNIVERSITY   (United States)

^b BEN GURION UNIVERSITY OF THE NEGEV   (Israel)

^c Israel Nature and Parks Authority and Israel Electric Corporation   (Israel)

^d FRIEDRICH SCHILLER UNIVERSITY JENA   (Germany)

^e UNIVERSITY OF KWAZULU NATAL   (South Africa)

Author keywords

Fire; Grazing; Honeycomb rippling model; Inter tree competition; Spatio temporal rainfall variation; Tree grass coexistence

Indexed keywords

COEXISTENCE; GRASS; SAVANNA; WOODY PLANT;

POACEAE;

EID: 29344472307     PISSN: 14338319     EISSN: 16180437     Source Type: Journal    
DOI: 10.1016/j.ppees.2005.10.001     Document Type: Article

References (108)

1. F.R. Adler Modeling the Dynamics of Life: Calculus and Probability for Life Scientists 1998 Brooks/Cole Publishing Company Pacific Grove
2. P.B. Adler, D.A. Raff, and W.K. Lauenroth The effect of grazing on the spatial heterogeneity of vegetation Oecologia 128 2001 465 479
3. C.J. Andersson Lake Ngami; or Explorations and Discoveries, During four Years' Wanderings in the Wilds of South Western Africa 1856 Hurst and Blackett London
4. S. Archer, D.S. Schimel, and E.A. Holland Mechanisms of shrubland expansion - land-use, climate or CO2 Climatic Change 29 1995 91 99
5. S. Archer, T.W. Boutton, and K.A. Hibbard Trees in grasslands: biogeochemical consequences of woody plant expansion E.-D. Schulze S.P. Harrison M. Heimann E.A. Holland J. Lloyd I.C. Prentice D. Schimel Global Biochemical Cycles in the Climate System 2001 Academic Press San Diego 115 137
6. D.J. Augustine Spatial heterogeneity in the herbaceous layer of a semi-arid savanna ecosystem Plant Ecol. 167 2003 319 332
7. D.J. Augustine, and S.J. McNaughton Regulation of shrub dynamics by native browsing ungulates on East African rangeland J. Appl. Ecol. 41 2004 45 58
8. M.E. Barnes Seed predation, germination and seedling establishment of Acacia erioloba in northern Botswana J. Arid Environ. 49 2001 541 554
9. F.C. Bell Precipitation D.W. Goodall R.A. Perry Arid Land Ecosystems: Structure, Functioning and Management vol. 1 1979 Cambridge University Press Cambridge 373 392
10. A.J. Belsky Tree/grass ratios in East African savannas: a comparison of existing models J. Biogeogr. 17 1990 483 489
11. A.J. Belsky Spatial and temporal landscape patterns in arid and semi-arid African savannas L. Hansson L. Fahrig G. Merriam Mosaic Landscapes and Ecological Processes 1995 Chapman & Hall New York 31 56
12. A.J. Belsky, and C.D. Canham Forest gaps and isolated savanna trees - an application of patch dynamics in two ecosystems BioScience 44 1994 77 84
13. R. Bergström Browse characteristics and impact of browsing on trees and shrubs in African savannas J. Veg. Sci. 3 1992 315 324
14. W.J. Bond, and G.F. Midgley A proposed CO2-controlled mechanism of woody plant invasion in grassland and savannas Global Change Biol. 6 2000 865 869
15. J.R. Brown, and S. Archer Woody plant invasion of grasslands: establishment of honey mesquite (Prosopis glandulosa var. glandulosa) on sites differing in herbaceous biomass and grazing history Oecologia 80 1989 19 26
16. J.R. Brown, and S. Archer Shrub invasion of grassland: recruitment is continuous and not regulated by herbaceous biomass or density Ecology 80 1999 2385 2396
17. H. Bugmann A review of forest gap models Climatic Change 51 2001 259 305
18. M.M. Cole The influence of soils, geomorphology and geology on the distribution of plant communities in savanna ecosystems B.J. Huntley B.H. Walker Ecology of Tropical Savannas. Ecological Studies vol. 42 1982 Springer Berlin 145 174
19. P. Couteron, and K. Kokou Woody vegetation spatial patterns in a semi-arid savanna of Burkina Faso, West Africa Plant Ecol. 132 1997 211 227
20. P. Danthu, M. Ndongo, M. Diaou, O. Thiam, A. Sarr, B. Dedhiou, and A. Ould Mohamed Vall Impact of bush fire on germination of some West African acacias Forest Ecol. Manage. 173 2003 1 10
21. M.A. Davis, J. Pergl, A.-M. Truscott, J. Kollmann, J.P. Bakker, R. Domenech, K. Prach, A.H. Prieur-Richard, R.M. Veeneklaas, P. Pyšek, R. del Moral, R.J. Hobbs, S.L. Collins, and S.T.A. Pickett Vegetation change: a reunifying concept in plant ecology Perspect. Plant Ecol. Evol. Syst. 7 2005 69 76
22. D.S. DeBell, and C.A. Harrington Density and rectangularity of planting influence 20-year growth and development of red alder Can. J. Forest Res. 32 2002 1244 1253
23. J. Du Toit Acacia karoo intrusion: the effect of burning and sparing Proc. Grassland Soc. S. Afr. 7 1972 23 27
24. P.S. Eagleson, and R.I. Segarra Water-limited equilibrium of savanna vegetation systems Water Resour. Res. 21 1985 1483 1493
25. R.J. Fensham, and J.E. Holman Temporal and spatial patterns in drought-related tree dieback in Australian savanna J. Appl. Ecol. 36 1999 1035 1050
26. P.G.H. Frost, and F. Robertson The ecological effects of fire on savannas B.H. Walker Determinants of Tropical Savannas 1987 ICSU Press Miami 93 140
27. Getzin, S., 2002. Formation and consequences of fire-induced structures in tropical and sub-tropical savannas. M.Sc. thesis, University of Potsdam, Potsdam, Germany.
28. J. Gignoux, J. Clobert, and J.C. Menaut Alternative fire resistance strategies in savanna trees Oecologia 110 1997 576 583
29. L. Gillson Evidence of hierarchical patch dynamics in an East African savanna? Landscape Ecol. 19 2004 883 894
30. G.C. Green Variability and probablity of rainfall in relation to coefficients of variation of rainfall series Agrochemophysica 1 1969 1 8
31. J.R. Gutierrez, and E.R. Fuentes Evidence for intraspecific competition in the Acacia caven (Leguminosae) savanna of Chile Oecol. Plantarum 14 1979 151 158
32. G.N. Harrington Effects of soil moisture on shrub seedling survival in a semi-arid grassland Ecology 72 1991 1138 1149
33. B.I. Hesla, L.L. Tieszen, and T.W. Boutton Seasonal water relations of savanna shrubs and grasses in Kenya J. Arid. Environ. 8 1985 15 31
34. S.I. Higgins, W.J. Bond, and S.W. Trollope Fire, resprouting and variability: a recipe for grass-tree coexistence in savannna J. Ecol. 88 2000 213 229
35. T.L. Hills Savannas: a review of a major research problem in tropical geography Can. Geogr. 9 1965 216 228
36. M.H.T. Hipondoka, J.N. Aranibar, C. Chirara, M. Lihavha, and S.A. Macko Vertical distribution of grass and tree roots in arid ecosystems of Southern Africa: niche differentiation or competition? J. Arid. Environ. 54 2003 319 325
37. M.E. Hochberg, J.C. Menaut, and J. Gignoux The influences of tree biology and fire in the spatial structure of the West African savanna J. Ecol. 82 1994 217 226
38. W.A. Hoffmann The effects of fire and cover on seedling establishment in a neotropical savanna J. Ecol. 84 1996 383 393
39. W.A. Hoffmann, and O.T. Solbrig The role of topkill in the differential response of savanna woody species to fire Forest Ecol. Manage. 180 2003 273 286
40. W.A. Hoffmann, B. Orthen, and A.C. Franco Constraints to seedling success of savanna and forest trees across the savanna-forest boundary Oecologia 140 2004 252 260
41. J.I. House, S.R. Archer, D.D. Breshears, and R.J. Scholes Conundrums in mixed woody-herbaceous plant systems J. Biogeogr. 30 2003 1763 1777
42. F. Jeltsch, S.J. Milton, W.R.J. Dean, and N. van Rooyen Tree spacing and coexistence in semiarid savannas J. Ecol. 84 1996 583 595
43. F. Jeltsch, G. Weber, W.R.J. Dean, and S.J. Milton Disturbances in savanna ecosystems: modelling the impact of a key determinant J.L. Usó C.A. Brebbia H. Power Ecosystems and Sustainable Development: Advances in Ecological Sciences 1998 Computational Mechanics Publications Southampton 233 242
44. F. Jeltsch, S.J. Milton, W.R.J. Dean, N. van Rooyen, and K.A. Moloney Modelling the impact of small-scale heterogeneities on tree-grass coexistence in semiarid savannas J. Ecol. 86 1998 780 794
45. F. Jeltsch, G.E. Weber, and V. Grimm Ecological buffering mechanisms in savannas: a unifying theory of long-term tree-grass coexistence Plant Ecol. 150 2000 161 171
46. R.W. Johnson, and J.C. Tothill Definition and broad geographic outline of savanna lands J.C. Tothill J.J. Mott Ecology and Management of the World's Savannas 1985 Australian Academy of Sciences Canberra, ACT 1 13
47. M.B. Kirkham Principles of Soil and Plant Water Relations 2005 Elsevier Amsterdam
48. W.T. Knoop, and B.H. Walker Interactions of woody and herbaceous vegetation in a southern African savanna J. Ecol. 73 1985 235 253
49. Kraaij, T., Ward, D., in press. Effects of rain, nitrogen, fire and grazing on tree recruitment and early survival in bush-encroached savanna, South Africa. Plant Ecol.
50. H.F. Lamprey Pastoralism yesterday and today: the overgrazing problem F. Bouliere Tropical Savannas: Ecosystems of the World 1983 Elsevier Amsterdam, The Netherlands 643 666
51. E. Medina, and J.F. Silva Savannas of northern South America: a steady state regulated by water-fire interactions on a background of low nutrient availability J. Biogeogr. 17 1990 403 413
52. J.C. Menaut, J. Gignoux, C. Prado, and J. Clobert Tree community dynamics in a humid savanna of the Côte-d'Ivoire: modelling the effects of fire and competition with grass and neighbours J. Biogeogr. 17 1990 471 481
53. K.M. Meyer, D. Ward, A. Moustakas, and K. Wiegand Big is not better: small Acacia mellifera shrubs are more vital after fire Afr. J. Ecol. 43 2005 131 136
54. J.J. Midgley, and W.J. Bond A synthesis of the demography of African acacias J. Trop. Ecol. 17 2001 871 886
55. S.J. Milton Spatial and temporal patterns in the emergence and survival of seedlings in arid Karoo shrubland J. Appl. Ecol. 32 1995 145 156
56. J. Mistry Savannas Progr. Phys. Geogr. 24 2000 273 279
57. A. Moore, J.A.J. van Eck, J.P. van Niekerk, and B.L. Robertson Evapotranspiration in three plant communities of a Rhigozum trichotomum habitat at Uppington J. Grassland Soc. S. Afr. 5 1988 80 84
58. P. Mordelet, J.C. Menaut, and A. Mariotti Tree and grass rooting patterns in an African humid savanna J. Veg. Sci. 8 1997 65 70
59. I. Noy-Meir Stability of plant-herbivore models and possible applications to savanna B.J. Huntley B.H. Walker Ecology of Tropical Savannas: Ecological Studies 1982 Springer Berlin 591 609
60. M. Obeid, and A. Seif El Din Ecological studies of the vegetation of the Sudan. III. The effect of simulation rainfall distribution at different isohyets on the vegetation of Acacia senegal on clay and sandy soil J. Appl. Ecol. 8 1971 203 209
61. T.G. O'Connor Acacia karoo invasion of grassland: environmental and biotic effects influencing seedling emergence and establishment Oecologia 103 1995 214 223
62. R.V. O'Neill, D.L. DeAngelis, T.F.H. Allen, and J.B. Waide A Hierarchical Concept of Ecosystems 1986 Princeton University Press Princeton, NJ
63. J.S. Perkins, and D.S.G. Thomas Spreading deserts or spatially confined environmental impacts? Land degradation and cattle ranching in the Kalahari desert of Botswana Land Degr. Rehab. 4 1993 179 194
64. G.L.W. Perry Landscapes, space and equilibrium: shifting viewpoints Progr. Phys. Geogr. 26 2002 339 359
65. H.W. Polley, H.S. Mayeux, H.B. Johnson, and C.R. Tischler Viewpoint: atmospheric CO2, soil water, and shrub/grass ratios on rangelands J. Range Manage. 50 1997 278 284
66. H. Polley, H.B. Johnson, and C.R.W. Tischler Woody invasion of grasslands: evidence that CO2 enrichment indirectly promotes establishment of Prosopis glandulosa Plant Ecol. 164 2003 85 94
67. H.H.T. Prins, and P.E. Loth Rainfall patterns as background to plant phenology in northern Tanzania J. Biogeogr. 15 1988 451 463
68. H. Remmert The Mosaic-Cycle Concept of Ecosystems 1991 Springer Berlin
69. I. Rodriguez-Iturbe, P. D'Odorico, A. Porporato, and L. Ridolfi On the spatial and temporal links between vegetation, climate, and soil moisture Water Resour. Res. 35 1999 3709 3722
70. J.J. San José, and M.R. Fariñas Temporal changes in the structure of a Trachypogon savanna protected for 25 years Acta Oecol. 12 1991 237 247
71. J.J. San José, M.R. Fariñas, and J. Rosales Spatial patterns of trees and structuring factors in a Trachypogon savanna of the Orinoco Llanos Biotropica 23 1991 114 123
72. M. Sankaran, J. Ratnam, and N.P. Hanan Tree-grass coexistence in savannas revisited - insights from an examination of assumptions and mechanisms invoked in existing models Ecol. Lett. 7 2004 480
73. R.J. Scholes Savanna R.M. Cowling D.M. Richardson S.M. Pierce Vegetation of Southern Africa 1997 Cambridge University Press Cambridge, MA 258 277
74. R.J. Scholes, and S.R. Archer Tree-grass interactions in savannas Annu. Rev. Ecol. Syst. 28 1997 517 544
75. R.J. Scholes, and B.H. Walker An African Savanna - Synthesis of the Nylsvley Study 1993 Cambridge University Press Cambridge, MA
76. E.-D. Schulze, G. Gebauer, H. Ziegler, and O.L. Lange Estimates of nitrogen fixation by trees on an aridity gradient in Namibia Oecologia 88 1991 451 455
77. D. Sharon The spottiness of rainfall in a desert area J. Hydrol. 17 1972 161 175
78. D. Sharon The distribution in space of local rainfall in the Namib Desert Int. J. Climatol. 1 1981 69 75
79. B.R. Sharp, and D.M.J.S. Bowman Patterns of long-term woody vegetation change in a sandstone-plateau savanna woodland, Northern Territory, Australia J. Trop. Ecol. 20 2004 259 270
80. C. Skarpe Shrub layer dynamics under different herbivore densities in an arid savanna, Botswana J. Appl. Ecol. 27 1990 873 885
81. C. Skarpe Structure of the woody vegetation in disturbed and undisturbed arid savanna Vegetatio 87 1990 11 18
82. C. Skarpe Spatial patterns and dynamics of woody vegetation in an arid savanna J. Veg. Sci. 2 1991 565 572
83. C. Skarpe Dynamics of savanna ecosystems J. Veg. Sci. 3 1992 293 300
84. G.N. Smit An approach to tree thinning to structure southern African savannas for long-term restoration from bush encroachment J. Environ. Manage. 71 2004 179 191
85. G.N. Smit, N.F.G. Rethman, and A. Moore Review article: vegetative growth, reproduction, browse production and response to tree clearing of woody plants in African savanna Afric. J. Range Forage Sci. 13 1996 78 88
86. T.M. Smith, and P.S. Goodman The effect of competition on the structure and dynamics of Acacia savannas in Southern Africa J. Ecol. 74 1986 1013 1044
87. T.M. Smith, and P.S. Goodman Successional dynamics in an Acacia nilotica-Euclea divinorum savannah in southern Africa J. Ecol. 75 1987 603 610
88. T.M. Smith, and B.H. Walker The role of competition in the spacing of savanna trees Proc. Grassland Soc. S. Afr. 18 1983 159 164
89. W.R. Teague, and G.N. Smit Relations between woody and herbaceaous components and the effects of bush-clearing in southern African savannas J. Grassland Soc. S. Afr. 9 1992 60 71
90. M.G. Turner, W.H. Romme, R.H. Gardner, R.V. O'Neill, and T.K. Kratz A revised concept of landscape equilibrium - disturbance and stability on scaled landscapes Landscape Ecol 8 1993 213 227
91. J.A. Van Vegten Thornbush invasion in eastern Botswana Vegetatio 56 1983 3 7
92. M.T. Van Wijk, and I. Rodriguez-Iturbe Tree-grass competition in space and time: insights from a simple cellular automata model based on ecohydrological dynamics Water Resour. Res. 38 2002 1179
93. B.H. Walker, and I. Noy-Meir Aspects of the stability and resilience of savanna ecosystems B.J. Huntley B.H. Walker Ecology of Tropical Savannas 1982 Springer Berlin 556 590
94. B.H. Walker, D. Ludwig, C.S. Holling, and R.M. Peterman Stability of semi-arid savanna grazing systems J. Ecol. 69 1981 473 498
95. H. Walter Die Verbuschung, eine Erscheinung der subtropischen Savannengebiete, und ihre ökologischen Ursachen Vegetatio 5/6 1954 6 10
96. H. Walter Ecology of Tropical and Subtropical Vegetation 1971 Oliver & Boyd Edinburgh
97. D. Ward The effects of grazing on plant biodiversity in arid ecosystems M. Shachak S.T.A. Pickett J.R. Gosz A. Perevolotsky Biodiversity in Drylands: Towards a Unified Framework 2004 Oxford University Press Oxford 233 249
98. D. Ward Do we understand the causes of bush encroachment in African savannas? Afr. J. Range Forage Sci. 22 2005 101 105
99. D. Ward, and T.P. Young Effects of large mammalian herbivores and ant symbionts on condensed tannins of Acacia drepanolobium in Kenya J. Chem. Ecol. 28 2002 921 937
100. D. Ward, D. Saltz, and B.T. Ngairorue Spatio-temporal rainfall variation and stock management in arid Namibia J. Range Manage. 57 2004 130 140
101. A.S. Watt Pattern and process in the plant community J. Ecol. 35 1947 1 22
102. J.F. Weltzin, and G.R. McPherson Spatial and temporal soil moisture partitioning by trees and grasses in a temperate savanna, Arizona, USA Oecologia 112 1997 156 164
103. Wiegand, K., Saltz, D., Ward, D., Levin, S.A., in revision. The role of size inequality in self-thinning: a pattern-oriented simulation model for arid savannas. Ecol. Modell.
104. K. Wiegand, D. Ward, and D. Saltz Multi-scale patterns in an arid savanna with a single soil layer J. Veg. Sci. 16 2005 311 320
105. B.P. Wilcox, D.D. Breshears, and C.D. Allen Ecohydrology of a resource-conserving semiarid woodland: effects of scale and disturbance Ecol. Monogr. 73 2003 223 239
106. T.B. Wilson, and E.T.F. Witkowski Water requirements for germination and early seedling establishment in four African savanna woody plant species J. Arid. Environ. 38 1998 541 550
107. T.P. Young, and W.K. Lindsay Role of even-age population structure in the disappearance of Acacia xanthophloea woodlands Afr. J. Ecol. 26 1988 69 72
108. W. Zucchini, P. Adamson, and L. McNeill A model of southern African rainfall S. Afr. J. Sci. 88 1992 103 109