Invasive Effects of Lantana camara in the Forests of Southern Garhwal Himalaya

摘要

Many invasive species such as Lantana camara, Parthenium hysterophorus, Eupatorium glandulosum, etc. are replacing many other herbaceous and woody plants of the Himalayan rangelands causing changes in forests and rangelands in the sub-Himalayan region of Garhwal. These species are usually early secondary successional species and replace other species by their allelopathic effects. Lantana camara L., an early successional shrub and native of South America, is prominent invasive species which is replacing other species and affecting regeneration of woody species in the forests of the Southern Garhwal Himalaya and is also causing changes in the soil nutrient status of these ecosystems. The study area included forests of the southern part of the District Tehri Garhwal. This species has invaded degraded slopes and roadsides, and abandoned agricultural areas. The altitudinal range of this species is upto 1800 m elevation, above which other invasive species are found on degraded lands. The degradation of forests, soil erosion, nutrient loss in the soil, adaptability of this species to degraded and eroded land conditions, and its growth in the cleared areas are accelerating the invasion activity by this species. The total net primary productivity of L. camara was 20.8 t ha-1 yr-1 in these shrublands. Nutrient status of the soil of L. camara shrubland was reported lower that of the forest soils. This invasive species has been a major ecological problem in these ecosystems and there is an urgent need to check its further spread.