Effects of Soil Heterogeneity and Species on Plant Interactions

Abstract

Plant interactions are central in driving the composition and structure of plant populations and communities. Soil heterogeneity and species identity can modulate such interactions, yet require more studies. Thus, a manipulative experiment was done where three soil heterogeneity levels were developed by mixing local soil and sand in three different ratios (i.e., soil:sand ratio = 2:8, 5:5, and 8:2), and three typical species (i.e., Festuca elata, Bromus inermis, and Elymus breviaristatus) were used in different combinations. Soil heterogeneity was assumed to affect plant interactions, which were in turn modified by species. Plant height was applied as an indicator for plant interactions. Relative competition intensity (RCI) was used to quantify plant interactions, where RCI was applied as a ratio of monoculture and mixture performance. Results showed that soil heterogeneity and soil heterogeneity × species significantly affected the RCI in mixtures compared with plant individuals growing alone (i.e., RCI1). However, species as a single factor did not affect RCI1. Moreover, species and soil heterogeneity × species significantly affected the RCI in mixtures compared with two individuals growing together (i.e., RCI2), and the difference between RCI1 and RCI2 (i.e., RCIdiff). Soil heterogeneity significantly affected RCI2 of F. elata. This study suggests that soil heterogeneity could buffer the stability of plant populations by modifying plant interactions, which would subsequently drive plant establishment. To explore the underlying mechanisms of such patterns, further studies considering more species and plant traits are needed.

Effect of Spraying Process on Physicochemical Properties and Vegetation Restoration of Vegetative Cement-Soil

“…The results of this study showed that soil bulk density increased at first and then decreased with age, and soil porosity decreased at first and increased at last with age, the reason was that the seed germination changed the permeability of the soil, this conclusion was consistent with the findings of Li Songyang et al [17] . The value of capacity was: process G > process S&G > process S and the porosity value was: process S > process S&G > process G. The reason is that the process G relies on wind pressure to spray the material onto the slope at a high speed, therefore the density and capacity are large, the porosity is small; while in process S, the material is scattered onto the slope and relatively loose, so the capacity is small and the porosity is large; the S&G process is the conjunction of process G after process S, so that the dry sprayed material has a high pressure pounding on the Wet spraying materials, the wet spraying material is compacted to a certain extent, therefore, the capacity of the vegetation cement soil in process S&G is greater than that of the process S.The compactness showed an overall increasing trend with age and showed the lowest porosity in process G and the highest in process S. Some scholars' research have shown that vegetation restoration has an increasing effect on total soil porosity [18] , which is consistent with the results of this study. The soil compactness can directly affects the physical, chemical and biological properties of soil [19] , specifically , the compact soil causing an increase in capacity and penetration resistance, a decrease in total porosity (mainly macropores), limiting soil air exchange, reducing soil water, available nutrients, forming soil hardened, reducing Soil biodiversity, enzyme activity, soil microbial biomass and soil fauna, etc.…”

Chromosome groups 5, 6 and 7 harbor major quantitative trait loci controlling root traits in bread wheat (Triticum aestivum L.)

“…Roots are pivotal for supplying water and nutrient to crops ( Lynch, 2007 ) and for anchorage ( Fitter, 2002 ), and thus directly affect grain yield ( Lynch, 2007 ). However, due to the heterogeneous nature of soil environments—variations in soil texture, pH, water and nutrient ( Li et al., 2021 ), root traits change according to environmental variations to capture edaphic resources ( Grossman and Rice, 2012 ; Rogers and Benfey, 2015 ). For example, under well-watered and low moisture conditions, the shallow root system of durum wheat contributed more to yield than the deep root system while under water-limited conditions, deeper roots contributed to higher grain yields ( El Hassouni et al., 2018 ).…”

Assessment of the effect of optimised field plot size on the crop yield

“…The different soil types also influence interactions of plants and the drawing of nutrients from the soil and hence also their capability of plant biomass formation (Li et al 2021). The entire plot (PZ A + PZ B) is made up of light or medium-heavy soils; these soil types are more susceptible to the transport of nutrients from the upper soil by the action of water.…”