Plant Diversity and Distribution Pattern in Tropical Dry …
211
Anthropogenic perturbation in tropical dry deciduous forests of Sathanur Reserve
forests creates niche space for ruderal weeds and alien invasive species to colonize
and establish. Ruderal weeds and alien invasive species were the dominant understory
community in all the study plots. Herbaceous community population in the study plots
were dominated by native ruderal species like Sida cordifolia, Sida cordata and Sida
acuta. Generally, these native ruderal species occur abundantly in the first year of
the fallow-land of agroecosystems, wastelands subjected to frequent disturbances,
adjacent to roads and rivulet, and moderately shaded and open areas of forests. The
greater density of these ruderal weeds implied that these study plots are still under
a certain level of disturbance. Alien invasive plants, Lantana camara and Ageratum
conyzoides were observed in 100% and 93% of plots respectively. In addition to
that, another exotic invasive species Prosopis juliflora was also registered in 43% of
plots. This successful colonization and establishment of alien invasion revealed that
these study plots are either under disturbance or have canopy opening. Many studies
have confirmed that the natural or anthropogenic perturbations pave way for a conducive environment for the establishment of invasive plants (Whitmore and Burslem
1996; Sundarapandian 1997; Sundarapandian and Karoor 2013). In shrub community, 32.18% of the population is contributed by exotic invasive species. Similarly,
in the herbaceous community, exotic invasive species contribution is 13.33%. The
present study reveals that the understory vegetation of tropical dry deciduous forest
at Sathanur Reserve forest is dominated by ruderal weeds and exotics. It indicates
that this forest is under the threat of anthropogenic pressure even though it has been
declared as a reserve forest. However, this forest ecosystem restores rich flora similar
to other tropical dry forests of the Eastern Ghats and central India. To impede the
plant invasion, timely measures are to be adopted to eliminate invasive species in
order to retain and conserve the native diversity.
Acknowledgements DSG thankfully acknowledges the fellowship provided by University Grants
Commission (UGC), Government of India. We thank the Tamil Nadu Forest Department for permission and help to complete the field work. We are also thankful to Prof. N. Parthasarathy, Department
of Ecology and Environmental Sciences, Pondicherry University, India for his help in identification of plants. We express our profound thanks to Mr. Pragash, Department of Earth Sciences,
Pondicherry University for helping me in the preparation of study area map.
References
Addo-Fordjour P, Anning AK, Larbi JA, Akyeampong S (2009) Liana species richness, abundance
and relationship with trees in the Bobiri forest reserve, Ghana: impact of management systems.
For Ecol Manag 157:1822–1828
Annaselvam J, Parthasarathy N (1999) Inventories of understory plants in a tropical evergreen forest
in the Anamalais, Western Ghats, India. Ecotropica 5:197–211
Bahuguna VK (1999) Forest fire prevention and control strategies in India. Int For Fire News 20:5–9
Behera SK, Misra MK (2006) Floristic and structure of the herbaceous vegetation of four recovering
forest stands in the Eastern Ghats of India. Biodivers Conserv 15:2263–2285
211
Anthropogenic perturbation in tropical dry deciduous forests of Sathanur Reserve
forests creates niche space for ruderal weeds and alien invasive species to colonize
and establish. Ruderal weeds and alien invasive species were the dominant understory
community in all the study plots. Herbaceous community population in the study plots
were dominated by native ruderal species like Sida cordifolia, Sida cordata and Sida
acuta. Generally, these native ruderal species occur abundantly in the first year of
the fallow-land of agroecosystems, wastelands subjected to frequent disturbances,
adjacent to roads and rivulet, and moderately shaded and open areas of forests. The
greater density of these ruderal weeds implied that these study plots are still under
a certain level of disturbance. Alien invasive plants, Lantana camara and Ageratum
conyzoides were observed in 100% and 93% of plots respectively. In addition to
that, another exotic invasive species Prosopis juliflora was also registered in 43% of
plots. This successful colonization and establishment of alien invasion revealed that
these study plots are either under disturbance or have canopy opening. Many studies
have confirmed that the natural or anthropogenic perturbations pave way for a conducive environment for the establishment of invasive plants (Whitmore and Burslem
1996; Sundarapandian 1997; Sundarapandian and Karoor 2013). In shrub community, 32.18% of the population is contributed by exotic invasive species. Similarly,
in the herbaceous community, exotic invasive species contribution is 13.33%. The
present study reveals that the understory vegetation of tropical dry deciduous forest
at Sathanur Reserve forest is dominated by ruderal weeds and exotics. It indicates
that this forest is under the threat of anthropogenic pressure even though it has been
declared as a reserve forest. However, this forest ecosystem restores rich flora similar
to other tropical dry forests of the Eastern Ghats and central India. To impede the
plant invasion, timely measures are to be adopted to eliminate invasive species in
order to retain and conserve the native diversity.
Acknowledgements DSG thankfully acknowledges the fellowship provided by University Grants
Commission (UGC), Government of India. We thank the Tamil Nadu Forest Department for permission and help to complete the field work. We are also thankful to Prof. N. Parthasarathy, Department
of Ecology and Environmental Sciences, Pondicherry University, India for his help in identification of plants. We express our profound thanks to Mr. Pragash, Department of Earth Sciences,
Pondicherry University for helping me in the preparation of study area map.
References
Addo-Fordjour P, Anning AK, Larbi JA, Akyeampong S (2009) Liana species richness, abundance
and relationship with trees in the Bobiri forest reserve, Ghana: impact of management systems.
For Ecol Manag 157:1822–1828
Annaselvam J, Parthasarathy N (1999) Inventories of understory plants in a tropical evergreen forest
in the Anamalais, Western Ghats, India. Ecotropica 5:197–211
Bahuguna VK (1999) Forest fire prevention and control strategies in India. Int For Fire News 20:5–9
Behera SK, Misra MK (2006) Floristic and structure of the herbaceous vegetation of four recovering
forest stands in the Eastern Ghats of India. Biodivers Conserv 15:2263–2285