Leaf photosynthesis of three typical plant species affected by the subsidence cracks of coal mining: a case study in the semiarid region of Western China

Abstract

Increased attention has been paid to effects of coal mining subsidence on the growth of plants. Studying the changes of plants photosynthetic physiology under the disturbance of coal mining subsidence is the basis for understanding dynamic exchanges of plant energy and water at that mining area. The 52302 working face of the Shendong mining area was selected as the experimental site, with Artemisia ordosica, Caragana korshinskii, and Populus spp. as the research targets. Changes in leaf photosynthesis were monitored in plants at a subsidence crack area. We showed collapse cracks decreased soil moisture and caused drought stress. The photosynthetic capacity of leaves was reduced. Compared with plants from the control area, stomatal conductance, photosynthetic CO2 assimilation, and transpiration rate were reduced in all three plant species. The activity of PSII reaction center and electron transport at the donor and acceptor sites significantly decreased.

Disturbance mechanism of coal mining subsidence to typical plants in a semiarid area using O-J-I-P chlorophyll a fluorescence analysis

“…The main soil types are loess and aeolian sandy soil that have a loose structure, poor resistance to erosion, and vulnerability to wind erosion. Human production activities in the mining area have led to the destruction and replacement of the original vegetation with artificial restoration species (Liu et al 2019a). The area was first mined 10 years ago and is currently being subjected to a second mining operation.…”

“…Chl fluorescence measurements were performed using a Handy PEA continuous excitation plant efficiency analyzer (Hansatech Instruments, Ltd., Norfolk, UK) from 8:30 to 12:00 h. The light source was red light with a wavelength of 650 nm, and the intensity of illumination was 3,500 μmol(photon) m -2 s -1 . The fluorescence signal was recorded with a maximum frequency of 10 5 points s -1 (each 10 μs) within 0-0.3 ms (Brestic et al 2012, Liu et al 2019a, after which the frequency of recording gradually decreased, resulting in the collection of 118 points within 1 s. The Chl fluorescence induction curve was measured shortly after the selected leaves were maintained in the dark for 20 min. Chl a fluorescence transient data were used to calculate basic parameters and the parameters required for the JIP-test.…”

“…Recent achievements in this field include the use of remote sensing and mathematical model-based methods to assess coal mining subsidence (Zhang et al 2015, Rošer et al 2018, the changes of soil physicochemical properties (Yang et al 2016, as well as the mitigation of subsidence influences (Luo 2008, Lv 2016 and the restoration of the disturbed land that resulted from mining (Clifford et al 2019, Feng et al 2019, Wang et al 2020. Some studies have focused on the broader changes of vegetation in the Loess Plateau coal mining area, where different scale observations derived from satellite imagery have determined that the vegetation coverage and biomass index is dynamic, and coal mining is one of the factors that drives the change in vegetation (Lei et al 2016, Liu et al 2019a. On a local scale, namely, the area of an above underground mining operation, the mechanism of influence of underground mining on individual vegetation is not well understood.…”

“…This limited the development of practical strategies and approaches used to achieve the goals of environmental protection and sustainable or green mining (Darmody et al 2014). In this regard, more research is needed to reveal and sustainably manage the vegetation at underground mining areas (Liu et al 2019a).…”

“…What are the key soil environmental factors that affect the growth of vegetation in subsidence areas? The damage to individual plants in a subsidence area is closely related to the disturbance of the root environment by collapse, which shows that the growth of the plant is subjected to the stress of environmental disturbance (Liu et al 2019a). As a classical monitoring method of photosynthesis, chlorophyll (Chl) fluorescence induction technology has become one of the most powerful and widely used technologies in the field of plant ecological research (Gray et al 2006, Carstensen et al 2019.…”