Study on water level ecological amplitude of Typha orientalis seedlings

Figures & data

Figure 1. Seedlings of T. orientalis.

Table 1. Average water quality index of test water (mg/L).

Index	TN	TP	NH4^+-N	NO3^--N	NO2^--N	CODMn
Numerical	0.546	0.033	0.314	0.1189	0.013	5.241

Figure 2. Schematic diagram of testing setup design.

Figure 3. Effect of water level on growth characteristics of T. orientalis seedlings.

Figure 4. Effect of water level on physiological characteristics of T. orientalis seedlings.

Table 2. Quadratic fitting equations of physiological characteristics of T. orientalis seedling growth under different environmental water levels.

Indices	Unit	Fitting equations	R^2
Plant height	cm	y = −0.0343x^2 + 0.6073x + 198.11	0.8309
Basal diameter	mm	y = −0.0011x^2 + 0.0556x + 13.153	0.7407
Leaf length	cm	y = −0.0267x^2 + 0.5153x + 160.49	0.8600
Leaf width	mm	y = −0.0004x^2 + 0.015x + 7.2881	0.7874
Leaf area	cm^2	y = −0.0192x^2 + 0.4426x + 96.725	0.8277
Biomass	g	y = −0.0038x^2 + 0.095x + 15.216	0.7210
Dead leaves rate	%	y = 0.0115x^2 − 0.0307x + 35.133	0.8334
Leaf moisture content	%	y = −0.0008x^2 + 0.1542x + 81.343	0.9574
Chl.a	mg·g^-1	y = −0.0002x^2 + 0.0027x + 1.5387	0.7145
Chl.b	mg·g^-1	y = −4E-05x^2 +0.0024x + 0.4749	0.7777
Car.	mg·g^-1	y = −7E-05x^2 + 0.0021x + 0.344	0.8998
Activity of SOD	U·g^-1	y = −0.0159x^2 + 0.8317x + 240.99	0.7827
Activity of POD	U·g^-1·min^-1	y = 0.0113x^2 + 0.2408x + 109.22	0.7086
Activity of CAT	U·g^-1·min^-1	y = −0.0244x^2 + 0.5334x + 97.027	0.6890
Soluble protein content	mg·g^-1	y=−0.0015x^2 + 0.011x + 15.998	0.6907
MDA content	µmol·g^-1	y = 3E-06x^2 + 8E-05x + 0.0206	0.7550
Root activity	mg·g^-1·h^-1	y = −0.0002x^2 + 0.0034x + 0.9129	0.9236

Table 3. Evaluation of ecological threshold value of T. orientalis seedlings.

Ecological threshold of water level	Unit	Maximum	Optimum （u）	Limit（t）	Optimum range [u-t, u + t]	Ecological amplitude [u-2t, u + 2t]
Plant height	cm	200.80	8.85	38.26	[-29.41, 47.11]	[-67.66, 85.36]
Basal diameter	mm	13.86	25.27	56.12	[-30.85, 81.39]	[-86.96, 137.50]
Leaf length	cm	162.98	9.65	39.07	[-29.42, 48.72]	[-68.48, 87.78]
Leaf width	mm	7.56	18.75	68.14	[-49.39, 86.89]	[-117.53, 155.03]
Leaf area	cm^2	99.28	11.53	35.95	[-24.42, 47.48]	[-60.38, 83.43]
Biomass	g	15.81	12.5	32.25	[-19.75, 44.75]	[-52.00, 77.00]
Chl.a	mg·g^-1	1.55	6.75	43.99	[-37.24, 50.72]	[-81.22, 94.72]
Chl.b	mg·g^-1	0.51	30.00	56.51	[-26.51, 86.51]	[-83.02, 143.02]
Car.	mg·g^-1	0.36	15.00	35.85	[-20.84, 50.84]	[-56.69, 86.69]
Activity of SOD	U·g^-1	251.87	26.15	62.93	[-37.05, 66.63]	[-99.71, 152.01]
Activity of CAT	U·g^-1·min^-1	99.94	10.93	32.00	[-20.62, 43.19]	[-53.07, 74.93]
Soluble protein content	mg·g^-1	16.02	3.67	51.67	[-48.00, 55.33]	[-99.67, 107.00]
Root activity	mg·g^-1·h^-1	0.93	8.50	34.05	[-25.55, 42.55]	[-59.59, 76.59]
Overall results			14.43		[-19.75, 42.55]	[-52.00, 74.93]