Ecological adaptation of root architecture to grassland degradation in <I>Potentilla acaulis</I>

Abstract

Aims Our objectives were to 1) examine the ecological adaptability of Potentilla acaulis to grassland degrada- tion from the perspective of root architecture, 2) reveal why it can be a dominant species in extremely degraded grassland and 3) discuss its important roles in vegetation restoration or succession and preventing grassland from desertification. Methods We collected relatively complete P. acaulis roots by trenching. The numbers of first vertical roots, length of horizontal root tillering and number of plant tillers were recorded in the field. The root analysis system of WinRHIZO was used to determine total root length, root surface area, total root volume, root average diameter, number of furcations, average branching angle, number of root axes, length of root axes, number of root tips, number of first lateral roots, length of first lateral roots, number of secondary lateral roots, length of secondary lateral roots, root diameters along root length, root surface area and root volume. The data were analyzed by one-way ANOVA and principal component analysis. Important findings In degraded grassland typified by Stipa grandis, the function of P. acaulis became more important in the community and its root range, root depth, the number of first vertical roots, the number of plant tillers and the length of horizontal root tillering increased significantly. The parameters of root surface area, length of secondary lateral roots, total root length and the number of furcations explained the adaptability of P. acaulis to grassland degradation. Roots with a diameter <2 mm had a significant effect on root surface area and total root length of single plants of P. acaulis. The three-dimensional root architecture of a broad-waist-inverted centrum was an advantageous configuration for P. acaulis to adapt for grassland degradation and can explain P. acaulis as a