184 



Trees and 



Grasses. 



Trees and 



Strobil- 



anthes, 



Climbers 



prevents the establishment of any Teak reproduction beneath 

 them. Even when such seedlings have become established 

 during the gregarious seeding and dying back of the bamboos 

 the young trees may still be caught up and suppressed by 

 the young bamboos resulting from the general seeding. 



In areas which have been cleared for cultivation in our 

 forests and then abandoned, the dense growth of grasses 

 which quickly takes possession of the ground often prevents 

 for many years the re- establishment of tree-species. The 

 mass of grass to some extent prevents the tree seeds from 

 reaching the ground, the dense network of grass roots in- 

 tersecting the superficial layers of soil in all directions have got 

 the start in the competition for water and mineral salts 

 and compete with the delicate roots of the few seedling trees 

 which may have germinated, while the heavy growth of grass 

 above the ground effectually prevents the struggling plants from 

 obtaining the light and air indispensable for their development. 



Similar in many respects, with regard to their effect on the 

 development of other plants, are some species of Strobilanthes. 

 The stems of the gregarious S. Wallichii in the Western Himala- 

 yas, for instance, " form a dense matted covering to the soil, and 

 prevent the seeds of the forest trees, chiefly oaks like Quercus 

 dilatata and semecarpifolia, and firs like Picea Morinda and Abies 

 Pindrow, from reaching the ground, or if they do reach the 

 ground, obtaining sufficient light fojr germination and growth."* 



163. Climbing plants again are 



often very injurious competitors of which our forests 

 contain many examples, the most striking perhaps being 

 the well-known Bauhinia Vahlii. The damage done by such 

 plants consists chiefly in the injurious competition for 

 light between their foliage and the crowns of the trees on which 

 they climb. The species mentioned, for instance, climbing to the 

 tops of the highest trees, eventually envelops them with its 

 mantle of enormous leaves which sometimes measure as much as 

 18 inches across. The dense curtains of its foliage effectually 

 prevent the access of light to the tree branches covered by them, 

 and the leaves on the latter being unable to manufacture food, 

 the tree is ultimately starved. The roots of such climbers also 

 *ire more or less injurious by competing in the soil with the 

 roots of the plants on which they climb for water and mineral 

 salts. Moreover, the pressure exerted by the coils of woody 

 climbers on the thickening stems and branches of the plants 



Manual of Indian Timbers by J. S. Gamble, 1902, p. 519. 



