Sand and clay mineralogy of soils of Garhwal Himalaya, Uttarakhand

Abstract

Fine sand and clay mineralogy of selected horizons of forest soils representing various landforms of Maldeota, Satengal and Dhanaulti areas of Raipur and Jaunpur ranges of Mussoorie forest division of Garhwal Himalaya were investigated. Light minerals constituted more than 80 percent of total fine sand fractions and consisted of quartz, feldspar and mica in order of their abundance. Heavy minerals occurred in minute amounts and constitute 20 percent of the minerals and were dominated by opaque minerals followed by biotite, chlorite, chloritized mica, zircon, garnet, hornblende, tourmaline, rutile etc. Quartz is the dominant mineral in Maldeota and Satengal sites followed by Dhanaulti while feldspar and mica are abundant in Dhanaulti followed by Maldeota and Satengal. Among the heavy minerals opaque minerals, biotite and calcite are present in appreciable quantity in all the three sites viz. Maldeoata, Satengal and Dhanaulti. The other heavy minerals are present in small quantities at all the three sites. The clay fractions from the soils of Maldeota are characterized by illite as the dominant clay mineral associated with kaolinite, chlorite, vermiculite and quartz. The clays from Satengal contained mixture of illite as dominant mineral followed by mica, mixed layer minerals, vermiculite, chlorite and quartz. The soil clays from Dhanaulti indicates the presence of illite, muscovite, kaolinite, mixed layer minerals, chlorite and small traces of vermiculite, calcite and quartz. Differences in mineralogical make up were mostly associated with nature and composition of parent material and degree of weathering. The study, therefore, suggests that soils of the study area contained low to moderate amount of weatherable minerals indicating their podzolic nature.

Impact of forest degradation on streamflow regime and runoff response to rainfall in the Garhwal Himalaya, Northwest India

“…These stormflow fractions are amongst the lowest recorded for forested tropical steeplands (Bonell 2005) and have typically been reported for volcanic headwater catchments underlain by deep and permeable soils of high retention capacity (Dagg and Pratt 1962, Bruijnzeel 1983, Tobón et al 2010. Generally speaking, the soils of the oak forest at Arnigad are not exceptionally deep (occasionally up to 155 cm, often <80 cm), but they are characterized by very high organic matter contents in the upper 20-30 cm as well as by high porosity (52-58%; Sharma et al 2006, Raina andGupta 2009). The few available surface infiltration tests (Qazi et al 2012) suggest very high values for the undisturbed forest soil (303-323 mm h -1 ).…”

“…Indeed, comparing volumetric soil moisture contents at field capacity (-33 kPa) at Arnigad (Tyagi et al 2013) with porosity values (i.e. soil saturation) for the corresponding layers reported by Raina and Gupta (2009) yielded approximate drainable pore space (DPS) values of ~23% for the top 25 cm vs 11-12% for the subsoil down to a depth of 80 cm, together representing a total DPS of ~120 mm. Repeating the exercise for the much wetter conditions that may be considered more representative of soil moisture values at the height of the monsoon (-1 kPa) gave a much lower but still appreciable DPS of ~60 mm.…”

“…The oaks are about 20 m tall (Raina and Gupta 2009) and have a diameter at breast height (DBH) of 30.6 ± 8.2 cm on average at a tree density of 502 ± 207 ha -1 . Forest degradation at Bansigad started around the mid-1990s when the forest was under government administration, but after a change to local private management, lopping and felling of trees came largely to a halt.…”

“…In the degraded forest at Bansigad (Fig. 2(b)), oaks (64%) are both less abundant (392 ± 190 ha -1 ) and smaller in diameter (15.5 ± 6.6 cm), whereas in addition the main co-dominant species is (introduced) Cupressus (17%), with various other species making up the remaining 19% (Raina andGupta 2009, Tyagi et al 2013). Trees in the degraded forest are typically much shorter (4-5 m) due to repeated lopping in the past, but a discontinuous shrub layer (dominated by Lantana camara L.) is usually present.…”

Recovery of soil microbial biomass, stoichiometry, and herb‐layer diversity with chronosequence of farmland land abandonment in the central Himalayas, India

“…The study area is covered with dissected valleys and hills, fluvial origin young alluvium plain, and glacier origin terrain in landforms. The principal parent material in study sites is phyllite, quartzite, slate, schists, shale, sandstone, limestone, and dolomite (Raina & Gupta 2009).…”