Abstract
Native species may have adaptive traits that are advantageous for overcoming the adverse environmental conditions faced during the early stages of mine land rehabilitation. Here, we examined the nitrogen (N) growth responses of two native perennial grasses (Axonopus longispicus and Paspalum cinerascens) from canga in nutrient-poor iron mining substrates. We carried out vegetative propagation and recovered substantial healthy tillers from field-collected tussocks of both species. These tillers were cultivated in mining substrates at increasing N levels. The tillering rates of both species increased with the N application. Nonetheless, only in P. cinerascens did the N application result in significant biomass increase. Such growth gain was a result of changes in leaf pigment, stomatal morphology, gas exchanges, and nutrients absorption that occurred mainly under the low N additions. Reaching optimum growth at 80 mg N dm−3, these plants showed no differences from those in the field. Our study demonstrates that an input of N as fertilizer can differentially improve the growth of native grasses and that P. cinerascens plants are able to deposit high quantities of carbon and protect soil over the seasons, thus, making them promising candidates for restoring nutrient cycling, accelerating the return of other species and ecosystem services.
Highlights
Environments undergoing intensive landscape transformations and the exposure of large quantities of raw geologic materials with poor soil structure and low organic matter and nutrient availability may receive support in the form of technical measures to improve the rehabilitation processes [1,2]
This open vegetation type can face a series of adverse environmental conditions, in particular, high UV radiation exposure, elevated daily temperatures, nutrient depletion in poorly developed soils, low water retention capacities, and prominent drought periods [10], and possibly carries adaptive traits that could be conducive to successful mine land rehabilitation
After 30 days in controlled conditions, 55% of the A. longispicus tillers remained alive, more than twice the 25% survival rate obtained for the P. cinerascens tillers (Figure 1)
Summary
Environments undergoing intensive landscape transformations and the exposure of large quantities of raw geologic materials (e.g., mining, roads, railways, and dam construction) with poor soil structure and low organic matter and nutrient availability may receive support in the form of technical measures to improve the rehabilitation processes [1,2]. Despite the benefits of replanting and the legal requirements related to offsetting biodiversity loss [11], very little information can be found in regard to the selection, propagation, and establishment of distinct plant communities of canga physiognomies [12,13,14], a rich savannalike vegetation type growing over iron-rich substrates at the tops of mountains [15,16] This open vegetation type can face a series of adverse environmental conditions, in particular, high UV radiation exposure, elevated daily temperatures, nutrient depletion in poorly developed soils, low water retention capacities, and prominent drought periods [10], and possibly carries adaptive traits that could be conducive to successful mine land rehabilitation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
