Root dynamics of artificial grassland for swards of differing ages in the ‘Three-River Source’ region

doi:10.11686/cyxb2020161

Abstract

Abstract:

In artificial grassland， measurement of root dynamic traits can indicate the efficiency of the vegetation in using soil resources and the progress of plant community restoration and ecological succession. In this study， the root dynamics of artificial grassland established 5， 6， 9 and 13 years previously was investigated in the Three-River Source region. Data were collected for two consecutive growing seasons （May-September 2015 and May-September 2016）， utilizing minirhizotron in situ monitoring technology. The results showed that the aboveground biomass and species richness decreased from 5 to 9 years and increased from 9 to 13 years. The soil physiochemical properties similarly changed in a “N” shape over the time series and the differences between different sward establishment years was significant. The majority of root growth and death occurred in the 0-10 cm soil depth， and root longevity， cumulative production and cumulative mortality all fluctuated across the time series of establishment dates. The average root standing crop continued to increase with increase in years established， and numbers of deep roots observed increased between 6 and 9 years after establishment. There were obvious seasonal changes in root production， mortality and standing crop. The growth peak was in June， the standing crop peak was in July， and the death-rate peak was in August， while the seasonal root growth peak of artificial grassland established for 9 years was later than in grassland of other ages. The number of years established and the soil depth directly affected root longevity， and other environmental factors indirectly affected root standing crop by influencing soil available nutrients or aboveground biomass. In summary， planting artificial grassland can promote the soil quality and increase the aboveground biomass， richness and root standing crop. The secondary degradation of planted artificial grassland from 6 to 9 years after establishment is only a temporary transitional stage. Therefore， at this stage， the establishment of suitable artificial management measures can ensure the stability of the soil nutrient status and accelerate the process of plant community succession， thereby improving the vegetation community stability and resilience of artificial grassland.

Key words: artificial grassland, cultivation years, root dynamic traits, plant community characteristics, soil physiochemical properties

Jie LI, Pan PAN, Chang-ting WANG, Lei HU, Ke-yu CHEN, Wen-gao YANG. Root dynamics of artificial grassland for swards of differing ages in the ‘Three-River Source’ region[J]. Acta Prataculturae Sinica, 2021, 30(3): 28-40.

Figures/Tables 9

References 55

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土层Soil layer	因子Factor	pH	SM	SOC	TN	TP	TK	AN	AP	AK
0~10 cm	根系生产量Root production	-0.103	0.292	0.317	0.063	0.695^**	0.249	0.123	0.533^*	0.529^*
	根系死亡量Root mortality	-0.251	0.095	0.148	-0.126	0.601^*	0.342	0.153	0.522^*	0.490
	根系现存量Root standing crop	-0.375	0.156	0.028	-0.286	0.533^*	0.186	0.336	0.535^*	0.476
	根系寿命Root longevity	-0.435	0.330	0.258	0.098	0.633^**	0.019	0.258	0.726^**	0.759^**
10~20 cm	根系生产量Root production	-0.398	0.146	-0.333	-0.248	0.491	0.629^**	0.678^**	0.565^*	0.753^**
	根系死亡量Root mortality	-0.369	-0.228	-0.235	-0.537^*	0.509^*	0.651^**	0.782^**	0.804^**	0.811^**
	根系现存量Root standing crop	0.142	-0.026	-0.217	-0.204	0.311	0.152	0.638^**	-0.026	0.462
	根系寿命Root longevity	0.437	-0.158	-0.308	-0.378	0.030	-0.136	0.395	-0.188	0.220

土层Soil layer	因子Factor	pH	SM	SOC	TN	TP	TK	AN	AP	AK
0~10 cm	根系生产量Root production	-0.103	0.292	0.317	0.063	0.695^**	0.249	0.123	0.533^*	0.529^*
	根系死亡量Root mortality	-0.251	0.095	0.148	-0.126	0.601^*	0.342	0.153	0.522^*	0.490
	根系现存量Root standing crop	-0.375	0.156	0.028	-0.286	0.533^*	0.186	0.336	0.535^*	0.476
	根系寿命Root longevity	-0.435	0.330	0.258	0.098	0.633^**	0.019	0.258	0.726^**	0.759^**
10~20 cm	根系生产量Root production	-0.398	0.146	-0.333	-0.248	0.491	0.629^**	0.678^**	0.565^*	0.753^**
	根系死亡量Root mortality	-0.369	-0.228	-0.235	-0.537^*	0.509^*	0.651^**	0.782^**	0.804^**	0.811^**
	根系现存量Root standing crop	0.142	-0.026	-0.217	-0.204	0.311	0.152	0.638^**	-0.026	0.462
	根系寿命Root longevity	0.437	-0.158	-0.308	-0.378	0.030	-0.136	0.395	-0.188	0.220

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