Do Epiphytes in Drier Climates Select Host Tree Substrates between Rough and Smooth Bole Textures and Crown and Stem, Vertical and Upright Stems? What Are the Implications for Water Catchment and Forest Management?

Chansa Chomba

School of Agriculture and Natural Resources, Disaster Management Training Centre, Mulungushi University, Kabwe, Zambia.

DOI: 10.4236/oje.2014.410054                

Abstract

Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures; crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transects were located at random in woody vegetation using quadrats 20 m × 20 m which were located every 100 m along 1 km long transects. For every host tree substrate sampled, tree species was identified and bark texture was determined. Presence and location of epiphytes were determined through direct observation. Epiphytes were collected, dried and weighed, so as to apportion biomass between rough and smooth bole textures, crown and trunk as well as stem inclination. Rough bole textured stems had more epiphytes of 1967 kg (89%) than smooth bole substrates of 313.48 kg (11%) and also inclined stems had higher biomass of 85% than vertical stems of 14.64% (χ² = P < 0.005). Trunk had less biomass of 32% and crown had higher biomass of 68% (Mann Whitney U test 0.002 < P < 0.05). It was concluded that epiphytes were more abundant on rough bole textured substrates and in crown than stem. It would appear that rough bole textured substrates provided better physical anchorage and stability against dislodging forces of wind and rain water, hence being suitable for epiphyte establishment and survival. Inclined substrates on the other hand provided a suitable habitat for accumulation of debris and moisture retention, seed settling, germination, and maximum exposure to sunlight all of which support germination and growth of epiphytes. Further research is required to determine successional colonization, incidences of host species specificity, rain water interception and retention and impact of fire on epiphyte biomass as these are important water catchment attributes.

Keywords

Epiphyte, Humid, Bark Texture, Rough Bole, Smooth Bole, Horizontal

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Chomba, C., Senzota, R., Chabwela, H. and Nyirenda, V. (2011) The Influence of Host Tree Morphology and Stem Size on Epiphyte Biomass Distribution in Lusenga Plains National Park, Zambia. Journal of Ecology and the Natural Environment, 3, 370-380.
[2]	Encyclopaedia Britannica (2010) Spanish Moss. Encyclopaedia Britannica Ultimate Reference Suite, Chicago.
[3]	Kelly, D.L. (1985) Epiphytes and Climbers of Jamaican Rainforest; Vertical Distribution, Life Forms and Life Histories. Journal of Biogeography, 12, 223-241. http://dx.doi.org/10.2307/2844997
[4]	Cornelissen, J.H.C. and Ter-Steege, H. (1989) Distribution and Ecology of Epiphytic Bryophytes and Lichens in Dry Evergreen Forest in Guyana. Journal of Tropical Ecology, 5, 131-150. http://dx.doi.org/10.1017/S0266467400003400
[5]	Yeaton, R.I. and Gladdstone, D.E. (1982) The Patterns of Colonization of Epiphytes on Calabash Trees (Crescentia alata) in Guanacaste Province. Costa Rica. Biotropica, 14, 137-140. http://dx.doi.org/10.2307/2387743
[6]	Catling, P.M., Brownwell, V.R. and Lefkovitch, L.P. (1986) Epiphytic Orchids in Belizean Grape Fruit Orchids; Distribution, Colonization and Association. Lindleyan, 1, 194-202.
[7]	Catling, P.M. and Lefkovitch, L.P. (1989) Associations of Vascular Epiphytes in Guatemalan Cloud Forest. Biotropica, 21, 35-40. http://dx.doi.org/10.2307/2388439
[8]	Tucker, G.F. and Powell, J.R. (1991) An Improved Canopy Access Technique. Journal of Applied Forestry, 8, 29-32.
[9]	Gentry, A.H. and Dobson, C.H. (1987) Contribution of Non-Tree Species Richness of a Tropical Rain Forest. Biotropica, 19, 149-156. http://dx.doi.org/10.2307/2388737
[10]	Nadkarni, N.M. (1984) Epiphyte Biomass and Nutrient Capital of a Neotropical Elfin Forest. Biotropica, 16, 249-256. http://dx.doi.org/10.2307/2387932
[11]	Tucker, G.F. and Powell, J.R. (1991) An Improved Canopy Access Technique. Journal of Applied Forestry, 8, 29-32.
[12]	Benzing, D.H. (1981) Bark Surface and the Origin and Maintenance of Diversity among Angiosperm Epiphytes: A Hypothesis. Selbyana, 5, 248-255.
[13]	Benzing, D.H. (1990) Vascular Epiphytes. Cambridge University Press, Cambridge. http://dx.doi.org/10.1017/CBO9780511525438
[14]	Todzia, C. (1986) Growth Habits, Host Tree Species and Density of Hemi Epiphytes on Barro Colorado Island, Panama. Biotropica, 18, 22-27. http://dx.doi.org/10.2307/2388357
[15]	Barkman, J.J. (1995) Phytosociology and Ecology of Cryptogamic Epiphytes. Van Gorcucm and Company, Assen.
[16]	Gentry, A.H. and Dobson, C.H. (1987) Contribution of Non-Tree Species Richness of a Tropical Rain Forest. Biotropica, 19, 149-156. http://dx.doi.org/10.2307/2388737
[17]	P’ocs, T. (1991) The Significance of Lower Plants in the Conservation of Mount Kilimanjaro. In: The Conservation of Mount Kilimanjaro, World Conservation Union, Gland.