Multiple risk factors in root survivorship: a 4‐year study in Concord grape

Abstract

Summary• Minirhizotron techniques were used to examine root lifespan in Vitis labruscana (Concord grape) for roots born in four different years that varied in rainfall.• Experimental vines were given irrigation (irrigated or not) and canopy pruning treatments (minimal or balanced). Root survival was assessed from 1997 through 2000 and analysed using Cox proportional hazards regression. Model covariates included pruning, irrigation, vine yield, soil depth, root diameter, time of root birth, and numbers of neighboring roots.• Soil depth, root diameter and time of birth consistently influenced root lifespan in all years ( P < 0.05). Deeper and coarser roots had longer lifespans. Roots born near bloom were shorter-lived than roots born later in the season. Pruning and irrigation influenced root lifespan in some years but their effects seemed to vary with growingseason environmental conditions.• These data underscore the value of long-term studies in distinguishing factors that consistently affect root lifespan from those that change annually with environmental conditions, and emphasize the diversity in life histories of fine roots within a species.

Response of the fine root production, phenology, and turnover rate of six shrub species from a subtropical forest to a soil moisture gradient and shading

“…Our results support the suggestions that the effects of soil moisture on root turnover appear to be species specific (Anderson et al 2003). In the present study, high-soil-moisture habitat was found to significantly inhibit the turnover rate of V. bracteatum, whereas the soil moisture did not affect the turnover rate of the other five species.…”

Considerations in the study of tree fine-root turnover with minirhizotrons

“…Our findings do not conflict with the expectation of a lower decomposition rate in the deeper soil. Furthermore, in some cases fine-root longevity has been shown to be greater in deeper soil than at the soil surface (Arnone et al, 2000;Anderson et al, 2003), which is also compatible with our results. Subdividing fine roots into several categories according to micro-size root diameter revealed that fine roots in the deeper soil tended to be coarser than at the soil surface, and coarser 'fine roots' tended to have longer life spans , suggesting that qualitative variations within fine roots (see below for related material) could also be closely related to the variation in fine-root turnover among soil depths.…”

Root Dynamics of Peach Replant Tolerant and Susceptible Rootstocks in Soilswith Different Cropping History

“…Tree root browning (or pigmentation) is linked to significant changes in root anatomical structures [18,44] and physiological function [31,45,46], and can be elicited by external factors such as soil moisture, temperature, fertility, and pathogens or herbivory [10,[47][48][49]. Studies comparing white and brown roots have reported lower respiration rates and reduced metabolic activity of brown versus white roots [31,45], suggesting a decline in nutrient and water absorption capacity following pigmentation [50,51].…”