干旱区生态环境知识资源中心

We studied the landscape impact of digging and clipping of vegetation by Indian crested porcupine Hystrix indica in an undulating topography in Islamabad. We recorded that the porcupine excavates and consumes subterranean organs of Johnson grass (Sorghum halepense), purple nutsedge (Cyperus rotundus), stumps of shisham (Dalbergia sissoo) and clipping of its saplings. Porcupine fresh digs varied in size according to depth of subsurface plant organs. The mean values of dig’s depth of Johnson grass were 27.71 +/- 6.99 cm with maximum and minimum values of 48.00 and 14.00 cm, respectively. The density of digs was less than one dig(m2), while the maximum number recorded was three (3) digs(m2). In case of purple nutsedge, the mean of depth was 6.49 cm, +/- 2.72 SD, with a maximum of 18 cm; the difference between the depth of digs was highly significant (t = 2.72, P = 0.007). The clipping of shisham saplings was caused at different heights from the ground level. The maximum height recorded was 27.5 cm, while the minimum was 2.00 cm with a mean of 7.98 cm +/- 5.67 SD. The average depth of digs of shisham stumps was 11.15 +/- 2.24 cm. Digs are temporary pocket like structures that trap soil, water, organic matter, and seeds which help in the germination and growth of annual plants including porcupine forage species, e.g., groundnut Arachis hypogeal, guar Cyamopsis tetragonolaba, field bindweed Convolvulus arvensis, and puncture vine Tribulits terrestris. Loose soil dug out by porcupines instantly becomes a part of the runoff thus enhancing ecosystem flows of water, soil, and nutrients.