Dynamics of phytoproductive functioning of low-mountain steppe landscapes of the Southern Urals

Abstract

We tested the hypothesis that landscape spatial pattern controlled the range of possible dynamic states. We used NDVI values in 1984-2019 in the low-mountain-steppe landscape in the Southern Urals and calculated Getis-Ord statistic to detect hot and cold spots of high and low green phytomass, respectively. We assessed the stability of hot and cold spots before and after establishment of protective regime and evaluated the contribution of the matter circulation in a catchment geosystem to the stability of phytoproductive functioning. The dynamics of the areas of spots of increased and decreased phytomass in the steppe landscape has a clearly pronounced seasonal variation, determined by the time of increased or decreased evaporation. The frequency of spots of high phytomass increases in the larger catchments. The mode of phytoproductive functioning in small catchments can be more holistic without the persistent areas with a meadow type of functioning. Sub-vertical and inclined bedding of sedimentary rock layers distorts the dependence of hot spots on catchment area. The protective regime in the zonal steppe phytocoenoses stabilizes the dynamics of green phytomass.