Spatial Patterns in a Prosopis – Juniperus Savannah
Keywords:
Competition, Facilitation, Grassland invasion, Woody plant encroachmentAbstract
We determined the distribution patterns and distance to nearest neighbor for Prosopis glandulosa and Juniperus pinchotii plants on deep and shallow soils. Ordination was used to compare microsite vegetation associated with open grassland habitat and the habitat proximal to big and small Prosopis and Juniperus plants. Analysis of similarities was used to provide a probability of plant group similarities to outside group similarity. Big Juniperus trees were randomly distributed on both soils, while the big Prosopis trees were random on the deep soil but aggregated on the shallow soil. Saplings of both species were strongly aggregated on both soils. Big and small Juniperus plants were positively associated with the dominant, established Prosopis trees and with litter cover but were negatively associated with bare ground and C4 grasses. In contrast, small Prosopis plants were negatively associated with both Juniperus and Prosopis trees on either soil and were positively associated with bare ground and C4 grasses. Prosopis trees facilitate establishment of Juniperus on deep or shallow soils, but Prosopis presence is probably not necessary for Juniperus establishment on either soil.References
Ansley RJ, Pinchak WE, Ueckert DN. 1995. Changes in redberry juniper distribution in Northwest Texas (1948 to1982). Rangelands 17:49-53.
Ansley RJ, Pinchak WE, Teague WR, Kramp BA, Jones DL, Jacoby PW. 2004. Long-term grass yields following chemical control of honey mesquite. J Range Manage 57:49-57.
Besag J, Gleaves JT. 1973. On the detection of spatial pattern in plant communities. Bull Int Stat Inst 45:153-158.
Brown JR, Archer S. 1991. Ecosystem level processes. In: Heitschmidt RK, Stuth JW (EDS). Grazing Management: An ecological perspective. pp 108-140.Timber Press, Portland, Oregon.
Chavez-Ramirez F, Slack RD. 1993. Carnivore fruit use and seed dispersal of two selected plants of the Edwards Plateau, Texas. Southwest Nat 38:141-145.
Clarke KR, Green RH. 1988. Statistical design and analysis for a ‘biological effects’ study. Mar Ecol Prog Ser 46:213-226.
Clarke KR, Ainsworth M (1993) A method of linking multivariate community structure to environmental variables. Mar Ecol Prog Ser 92:205-219.
Clarke KR, Warwick RM. 2001. Changes in marine communities: an approach to statistical analysis and interpretation. 2nd edition. PRIMER-E: Plymouth, England
Correll DS, Johnston MC. 1970. Manual of the vascular plants of Texas. Texas Research Foundation, Renner, Texas.
Daubenmire R. 1968. Plant Communities: A textbook of Plant Synecology. Harper and Row Publishing, New York
Diggle PJ. 1983. Statistical Analysis of Spatial Point Patterns. Academic Press, London.
Diggs GM, Lipscomb BL, O’Kennon RJ (1999) Illustrated Flora of North Central Texas. Botanical Research Institute of Texas, Fort Worth, US.
Dowhower SL, Teague WR, Ansley RJ, Pinchak WE. 2001. Dry-weight-rank method assessment in heterogeneous communities. J Range Manage 54:71-76.
Dye KL, Ueckert DN, Whisenant SG. 1995. Redberry juniper – herbaceous understory interactions. J Range Manage 48:100-107.
Ellis D, Schuster JL. 1968. Juniper age distribution on an isolated butte in Garza County. Southwest Nat 13:343-348.
Fowler NL. 1986. The role of competition in plant communities in arid and semiarid regions. Ann Rev Ecol Syst 17:89-110.
Fuhlendorf SD, Smeins FE, Grant WE. 1996. Simulation of a fire-sensitive ecological threshold: A case study of Ashe juniper on the Edwards Plateau of Texas, USA. Ecol Mod 90:245-255.
Grubb PJ. 1977. The maintenance of species-richness in plant communities: the importance of the regeneration niche. Biol Rev 52:107-145.
Grundy IM, Campbell BM, Frost PGH. 1994. Spatial pattern, regeneration and growth rates of Brachystegia spiciformis and Julbernardia globiflora. Vegetatio 115:101-107.
Haas RH, Meyer RE, Scifres CJ, Brock JH. 1973. Growth and development of mesquite. Research Monographs 1, Texas Agricultural Experiment Station, College Station, US.
Heitschmidt RK, Ansley RJ, Dowhower SL, Jacoby PW, Price DL. 1988.Some observations from the excavation of honey mesquite root systems. J Range Manage 41:227-231.
Heitschmidt RK, Dowhower SL. 1991. Herbage response following control of honey mesquite within single tree lysimeters. J Range Manage 44:144-149.
Hines WGS, Hines RJO. 1979. The Eberhardt index and the detection of non-randomness of spatial point distributions. Biometrika 66:73-80.
Jackson JT, van Auken OW. 1997.). Seedling survival, growth and mortality of Juniperus ashei (Cupressacae) in the Edwards plateau region of central Texas. Texas J Sci 49:267-278.
Johnson PA, Gerbolini D, Ethridge D, Britton C, Ueckert D. 1999. Economics of redberry juniper control in the Texas Rolling Plains. J Range Manage 52:569-574.
Krebs CJ (1989) Ecological Methodology. Harper Collins, New York.
Laxson JD, Schacht WH, Owens MK. 1997. Above-ground biomass yields at different densities of honey mesquite. J Range Manage 50:550-554.
McPherson GR, Wright HA, Wester DB. 1988. Patterns of shrub invasion in semiarid Texas grasslands. Am Midl Nat 120:391-397.
McPherson GR, Wright HA. 1987. Factors affecting reproductive maturity of redberry juniper (Juniperus pinchotii). For Ecol Manage 21:191-196.
McPherson GR, Wright HA. 1989. Direct effects of competition on individual juniper plants: a field study. J Appl Ecol 26:979-988.
McPherson GR, Wright HA. 1990. Effects of cattle grazing and Juniperus pinchotii cover on herb cover and production in western Texas. Am Midl Nat 123:144-151.
McPherson GR, Rasmussen GA, Wester DB, Masters RA. 1991. Vegetation and soil zonation associated with Juniperus pinchotii Sudw. trees. Great Basin Nat 51:316-324.
Parajulee MN, Slosser JE, Montadon R, Dowhower SL, Pinchak WE. 1997. Rangeland grasshopper (Orthoptera: Acrididae) associated with mesquite and juniper habitats in the Texas Rolling Plains. Environ Entomol 26: 528-536.
Phillips D.L, McMahon, JA. 1981. Competition and spacing patterns in desert shrubs. J Ecol 69:97-115.
Prentice IC, Werger MJA. 1985. Clump spacing in a desert shrub community. Vegetatio 63:133-139.
Ruthven DC, Fulbright TE, Beasom S.L, Hellgren EC. 1993. Long-term effects of root plowing on vegetation in the eastern south Texas plains. J Range Manage 46:351-354.
Scifres CJ. 1980. Brush management principles and practices for Texas and the southwest. Texas. A&M Univ. Press, College Station, Texas, US.
Skarpe C (1991) Spatial patterns and dynamics of woody vegetation in an arid savanna. J Veg Sci 2:565-572.
Smith MA, Wright HA, Schuster JL. 1975. Reproductive characteristics of redberry juniper. J Range Manage 28:126-128.
Smith TM, Goodman PS. 1987. Successional dynamics in an Acacia nilotica – Euclea divinorum savannah in southern Africa. J Ecol 75:603-610.
Smith TM, Walker BH. 1983. The role of competition in the spacing of savanna trees. Proc Grassl Soc South Afr 18:159-164.
Sprugel DG. 1976. Dynamic structure of wave-regenerated Abies balsamea forests in the north-eastern United States. J Ecol 64:889-912.
Szwagrzyk J, Czerwczak M. 1993. Spatial patterns of trees in natural forest of East-Central Europe. J Veg Sci 4:469-476.
Teague WR, Dowhower SL, Whisenant SG, Flores-Ancira E. 2001. Mesquite and grass interference with establishing juniper seedlings. J Range Manage 54:680-684.
Thurow TL. 1991. Hydrology and erosion. In: Heitschmidt RK, Stuth JW (EDS). Grazing management: An ecological perspective. pp. 141-160. Timber Press, Portland, Oregon, US.
Whittaker RH, Gilbert LE, Connell JH. 1979. Analysis of two-phase pattern in a mesquite grassland. Texas J Ecol 67:935-952.
Wright HA, Bailey AW. 1982. Fire Ecology. United States and Canada. John Wiley and Sons, New York, US.
