Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms

Abstract

Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

Nutrient remobilization in tree foliage as affected by soil nutrients and leaf life span

“…Calcium and Mg transport is thus controlled by exchange reactions and depends to a great extent on the flux of cations able to exchange with Ca and Mg (Augusto et al. , Funk and Amatangelo ). Moreover, Ca and Mg uptake in plant roots is mainly a passive process that depends on the mass flow (Marschner ).…”

“…In addition, because calcium (Ca) is not easily remobilized from foliage and because actual evapotranspiration drives foliage Ca content (Augusto et al. , Marschner , Funk and Amatangelo , Kumar et al. ), we hypothesize that climate can indirectly influence the Ca remobilization rate.…”

Effect of deprivation of selected single nutrients on biometric parameters of cedar seedlings (Acrocarpus fraxinifolius) grown in nutritive solution

“…Ca is also an essential macronutrient (Funk et al, 2013) found in association with the stabilization of the cell wall (White and Broadley, 2003). Plants growing under deficiency of Ca show a reduced number of leaves, early fall of folioles, and dying of the apical bud.…”

Macronutrients Omission in the Growth of Cotton, BRS Topázio Cultivar Grown in Nutritious Solution

“…Calcium is an essential macronutrient for plants [25], playing the important function of cell wall stabilization [26]. In addition, calcium ions and indoleacetic acid influence cell elongation and differentiation [27], and deficiency of this element may retard growth and cause meristem death [22].…”