There is a growing recognition that accurate predictions of plant and ecosystem responses to global change require
a better understanding of the mechanisms that control acquisition of growth-limiting resources. One such key
mechanism is root physiological capacity to acquire nutrients. Changes in kinetics of root nitrogen (N) uptake
might influence the extent to which terrestrial ecosystems will be able to sequester excesses in carbon (C) and N
loads. Despite its significant role in determining plant and ecosystem cycling of C and N, there is little information
on whether, or how, root nutrient uptake responds to global change. In this review various components of global
change, namely increased CO2 concentration, increased soil temperature and increased atmospheric N deposition
and their effects on kinetics of root nutrient uptake are examined. The response of root nutrient uptake kinetics
to high CO2 is highly variable. Most of this variability might be attributable to differences in experimental
protocols, but more recent evidence suggests that kinetic responses to high CO2 are also species-specific. This
raises the possibility that elevated CO2 might alter community composition by shifting the competitive interaction
of co-occurring species. Uptake of NH4+ and NO3− seem to be differentially sensitive to high CO2, which could
influence ecosystem trajectory toward N saturation. Increased soil temperature might increase N and P uptake
capacity to a greater extent in species from warm and fluctuating soil habitats than in species from cold and stable
soil environments. The few available data also indicate that increased soil temperature elicits a differential effect
on uptake of NH4+ versus NO3−. Root uptake kinetics are generally down-regulated in response to long-term
exposure to atmospheric N deposition. The extent of this down-regulation might, however, vary among species,
stages of succession, land-use history and plant demand. Nonetheless, it is suggested that root N uptake kinetics
might be an accurate biological indicator of the ecosystem capacity to retain N. The results reviewed here clearly
highlight the scanty nature of the literature in the area of root nutrient absorption responses to global change. It
is also clear that effects of one component of global change on root nutrient absorption capacity might be
counterbalanced by another. Therefore, the generalizations offered here must be viewed with caution and more
effort should be directed to rigorously test these initial observations in future research.