A comparison of the root growth, root morphology and root response to defoliation of Aristida ramosa R.Br. and Danthonia linkii Kunth

Abstract

Establishing plants of Aristida ramosa R.Br. and Danthonia linkii Kunth grown in root observation tubes differed markedly in their root growth and root morphology. Radicle extension of A. ramosa proceeded far more rapidly than that of D. linkii, and root branching occurred earlier and to a much greater extent in D. linkii. From 2 months after germination onwards, the maximum rooting depth of A. vamosa was greater than that of D. linkii, although total root dry weights for the two species were not significantly different. At 25 weeks from germination, 48 % of the root dry weight of D. linkii was present in the 0-10 cm level of the soil profile, while the corresponding figure for A. ramosa was 33 %. Root weight and rooting depth of both species were severely reduced by foliage clipping at weekly or monthly intervals, with roots being more sensitive to clipping than shoots. Clipping led to a concentration of root mass in the 0-10 cm level. The rapidly establishing seedling root system of A. vamosa would give it a competitive advantage over D. linkii in the environment of the north-western slopes of New South Wales. The results of the clipping trial suggest that grazing management may be manipulated to alter the relative abundance of A. ramosa and D. linkii in native pastures.

Fine Root Biomass and Its Relationship to Evapotranspiration in Woody and Grassy Vegetation Covers for Ecological Restoration of Waste Storage and Mining Landscapes

“…Information is limited on comparative root biomass production by grass and woody species in the same environment, but grasses are reported to produce as little as about a quarter of roots produced by trees (Mordelet andothers 1997, Schenk andJackson 2002). Reductions in root production in the grass was expected due to mowing, as found in an earlier study (Harradine and Whalley 1981), and would have been further exacerbated by the winter dormancy, when photosynthetic rates are low and assimilates are preferentially allocated to the shoots to facilitate reestablishment (Richards 1984). Root biomass produced by the three woody vegetation covers (Figure 2) consisting of the two plantations and the remnant woodland were consistent with their ages and did not show any correlations with carbon, nitrogen or phosphorus contents in the soil or in the foliage; we found only a marginal correlation between root biomass and C:N in soil and foliage (r = 0.90).…”

Regrowth capacity in relation to defence strategy in Stipa clarazii and Stipa trichotoma, native to semiarid Argentina

“…Our results did not support the hypothesis that regrowth capacity after defoliation is higher in palatable than in unpalatable grasses (Noy‐Meir & Walker 1986). In contrast, the hypothesis was supported in a comparison between the unpalatable grass Aristida ramosa and the palatable grass Danthonia linkii in Australia (Harradine & Whalley 1981; Lodge & Whalley 1985).…”

Effects of Summer Grazing Strategies on Organic Reserves and Root Characteristics of Big Bluestem

“…(Arredondo and Johnson, 1998), and Danthonia linkii Kunth (Harradine and Whalley, 1981). Root length also was reported to be sensitive to defoliation and likely is the principal factor affecting root volume of grasses (Harradine and Whalley, 1981, Arredondo and Johnson, 1998, Engel et al, 1998). In general, root diameter is reduced by repeated defoliation (Evans, 1971; Chapin and Slack, 1979; Chapin, 1980).…”