Effects of different soil water potentials on seedling growth rhythm and seedling quality of Populus tomentosa
-
摘要:目的 探讨苗圃育苗过程中不同土壤水势条件下毛白杨苗木的生长节律、形态及生理响应规律,为制定合理灌溉方案提供参考。方法 以毛白杨1年生苗为材料,设置3个土壤水势阈值(−20、−40、−60 kPa,即灌溉起始阈值),并以生产上常规灌溉作为对照(灌溉起始阈值 < −80 kPa),通过Logistic方程拟合苗木生长模型并划分生长阶段,研究不同土壤水势下毛白杨苗木生长节律、苗高地径生长、生物量分配和养分含量的变化。结果 (1)与常规灌溉(CK)相比,以−20 kPa作为灌溉起始阈值能够显著促进苗木生长,苗高、地径平均提高了29.33%和24.12%,生物量显著增加了176.17%,且茎根比优于−40和−60 kPa处理。(2)不同土壤水势处理下,毛白杨苗高、地径苗期生长均呈现“S”型曲线,且Logistic方程拟合效果较好,可以用来进行苗高和地径生长的预测和分析;同时苗木苗高与茎生物量、地径和根生物量显著正相关,可以通过苗高、地径的测量值估算苗木生物量。(3)根据毛白杨1年生苗木的苗高生长规律可将生长期划分为4个阶段:成活期,移苗至移苗后15 d;生长初期,移苗后16 ~ 53 d;速生期,移苗后54 ~ 138 d;木质化期,移苗后139 ~ 220 d。(4)毛白杨苗木茎养分质量分数无明显变化规律,根养分质量分数随土壤水势升高总体呈降低趋势,常规灌溉下苗木茎、根养分质量分数最大,显著高于各处理15.14% ~ 46.43%;养分单株质量规律与质量分数规律相反,−20 kPa处理下苗木各养分单株质量最大,高于常规灌溉处理 100.08% ~ 237.51%。(5)以−20 kPa作为灌溉起始阈值时,苗木质量指数综合评定结果最优,苗木质量最佳。结论 土壤水势对毛白杨苗木的生长和生物量积累有显著影响,距地表10 cm处以−20 kPa作为速生期灌溉起始阈值时,苗木的苗高、地径、生物量和养分单株质量最大。Abstract:Objective This research was carried out to study the effect of different soil water potentials on seedling growth rhythm, morphology and physiology of Populus tomentosa seedlings, so as to provide a scientific basis for precision irrigation strategy and parameters.Method One-year-old Populus tomentosa seedlings were used as materials and treated with three water potential conditions (−20, −40, −60 kPa of soil water potential threshold) and conventional irrigation was used as control (initial irrigation threshold < −80 kPa), then Logistic equation was adopted to establish seedling growth model and divide the growth stage, and the changes of seedling growth rhythm, biomass allocation and nutrient accumulation under different soil water potentials were studied.Result (1) Compared with CK, seedling height and ground diameter increased by 29.33% and 24.12% on average, while biomass was significantly increased by 176.17% under −20 kPa treatment, shoot to root ratio of seedlings under −20 kPa treatment was superior to −40 and −60 kPa treatments. (2) Under different soil water potential treatments, seedling height and ground diameter presented a curve changed like “S” and significantly fitted with Logistic equation, which can therefore be used to predict the seedling growth. Stem and root biomass were significantly correlated with seedling height and ground diameter, respectively, so seedling biomass can be predicted referring to seedling height and ground diameter. (3) The growth phase according to one-year-old P. tomentosa seedling height growth can be divided into 4 stages: establishment phase, from transplanting to 15 d after transplanting; early growth phase, 16 to 53 d; rapid growth phase, 54 to 138 d; and hardening phase: 139 to 220 d. (4) Nutrient concentration of P. tomentosa seedling shoot showed no significant trend, but root concentration showed a tendency of dropping with the increase of soil water potential. The highest stem and root nutrient concentration was found in CK, which was 15.14%−46.43% higher than other treatments; while nutrient content had the opposite pattern, that is, under −20 kPa treatment, the nutrient content was the highest, 100.08%−237.51% higher than CK. (5) P. tomentosa seedlings had the best seedling integrated evaluation results and seedling quality under −20 kPa treatment.Conclusion Soil water potential has significant effects on seedling growth and biomass allocation of Populus tomentosa seedlings. The seedlings have the highest height, ground diameter, biomass and nutrient content when −20 kPa is chosen as irrigation threshold of 10 cm from the surface, the seedling height, ground diameter, biomass and nutrient mass per plant are the largest.
-
Keywords:
- soil water potential /
- Populus tomentosa /
- growth rhythm /
- seedling quality /
- directive breeding
-
根据造林地条件,采取相应栽培措施定向培育苗木,能提高困难立地条件下的造林成功率[1-4]。基于目标苗木概念进行苗圃生产更易获得高质量苗木,但许多造林者经常忽视苗圃育苗措施的重要作用[5]。灌溉是苗圃育苗过程中控制苗木质量的关键措施之一[6],根据苗木生长节律制定合适的灌溉策略,能有效提高苗木质量和造林成活率[7]。目前国内外关于容器苗培育的灌溉参数已有许多研究,山杨(Populus tremuloides)苗木在70%容器重量时灌溉至饱和最利于苗木高生长[8],桃金娘(Luehea divaricata)苗木则需要保持16 mm/d的灌溉量来维持生长[9],而75%基质饱和含水量最利于底部渗灌条件下栓皮栎(Quercus variabilis)容器苗的形态生长和养分积累[10]。但传统裸根苗大田灌溉多凭经验,缺乏量化指标,不易实现标准化生产。通过监控土壤水势制定灌溉策略,不仅能确定合适的灌溉阈值,减少土壤蒸发和渗漏[11-13],还能有效规避工人经验的局限。因而,探究苗木生长期水分需求信息,确定苗木生长的适宜土壤水势范围,对提高灌溉效果和苗木质量有重要意义。
国内外学者在土壤水势与植物生长方面进行了大量研究。对水曲柳(Fraxinus mandshurica)苗木研究[14]发现:随着土壤水势逐渐降低,土壤水分有效性迅速下降,苗木生长速度减缓。在管理毛白杨(Populus tomentosa)人工林时,以−25 kPa作为灌溉起始阈值可以显著提高表层土壤的水分有效性和林地生产力[15]。对苹果(Malus pumila)[16]和柑橘(Citrus reticulata)[17]的研究发现:在不同生长发育阶段采取不同灌溉策略,能显著影响其生长过程和果实质量。生长过程中灌溉策略的调整,会影响苗木生长节律和出圃苗木的质量[2,18],因此培育苗木时,应当结合造林地条件选择相应水势范围,在降低成本的同时生产相应的目标苗木,但相关研究在裸根苗育苗中鲜有报道。
毛白杨作为我国特有的乡土树种,在华北地区广泛栽培[19],土壤水分是其生长主要限制因子[20-21]。现有关于毛白杨苗木的研究,多集中于盆栽苗木的光合[22]、蒸腾耗水[23]、施肥[24]、水肥耦合[25]等方面,而关于水分对其苗木生长节律及苗木质量的影响少见报道,仅裴保华[26]和董雯怡等[25]分别对其幼龄林和当年扦插苗的生长节律进行过一定总结。本试验通过研究不同土壤水势对毛白杨苗木生长节律和苗木质量的影响,寻找最佳灌溉参数,以期为毛白杨苗木定向培育过程中苗木质量的提高和水分管理策略的制定提供参考。
1. 材料与方法
1.1 试验地概况
试验苗圃位于山东省聊城市冠县国有苗圃(115°22′10″E、36°30′56″N),该地区为温带大陆性气候,四季分明,年平均降水540.4 mm,其中70%以上集中在7—9月,秋季气温下降迅速,降水减少,冬季寒冷干燥。年均气温13.1 ℃,全年平均日照总时数2 567 h,无霜期199 ~ 227 d。2018年6—9月苗圃降水达220.7 mm,为往年同时期降水量的43.1%,且60%以上降水集中在8月。
苗圃土壤为粉质黏壤土,土壤全氮含量0.46 g/kg,全磷含量0.79 g/kg,有机质含量10.94 g/kg,密度1.25 g/cm3,pH为8.1,田间持水率42.22%。
1.2 试验材料
试验所用的“北林雄株1号”毛白杨苗木购自冠县国有苗圃,选取长势相近的健壮组培苗(单株苗高(13.57 ± 1.52) cm,地径(2.95 ± 0.33) mm),于2018年春移植至大田,株行距0.3 m × 1.0 m,移植前施底肥900 kg/hm2(N∶P2O5∶K2O = 15∶15∶15,山东联盟磷复肥公司),并在地表铺设微喷管(国产五孔加厚微喷管,喷水高度0.5 m,单个试验小区微喷管流量约21.8 L/min,对照漫灌流量约150 L/min),7月中旬追施尿素1 050 kg/hm2,6月下旬至9月上旬每10 d人工除草一次。苗木移植后大水漫灌3次,每次间隔2 ~ 3 d以确保苗木成活,待苗木长出3 ~ 5片新叶后进行灌溉试验。
1.3 研究方法
1.3.1 试验设计
2018年4月19日进行试验布设,以土壤水势为参试因子,采用单因素完全随机区组设计,设置3个区组,每个区组4个小区,分别对应3个水势处理及对照,相邻小区间隔3 m,并埋设50 cm深塑料布进行隔断,单个小区面积48 m2,内含苗木100株,每个小区内在南北中轴线上等间距布设3个张力计测定土壤水势,结合席本野等[27]研究结果和苗木根系分布的田间实测数据,将陶瓷头布设在距离地表10 cm处。各处理土壤水势分别为−20 kPa(A)、−40 kPa(B)、−60 kPa(C)[27],并以常规灌溉作为对照(CK,水势 < −80 kPa,每7 ~ 10 d视土壤干旱情况漫灌至饱和),共计1 200株苗木。当小区内张力计平均读数降至设定阈值时,打开水泵灌溉至饱和[15],试验于2018年9月20日结束后,恢复苗圃常规管理(约20 d漫灌一次),并于10月上旬停灌,促进苗木木质化。
1.3.2 测定指标
当移植后的苗木长出3 ~ 5片新叶时,每个小区内随机选取长势相近的30株苗木进行挂牌,用卷尺和游标卡尺每15 d分别测量一次苗高和地径。2018年12月上旬苗木完全落叶后进行全株破坏取样,采用对角线法,每个小区内选取5株样苗,将根、茎分别装入纸袋,烘箱内70 ℃下烘干48 h至恒质量,称量二者生物量。随后将烘干的根、茎样品粉碎,过60目筛后,四分法称取样品0.200 g,用浓H2SO4-H2O2法进行消煮,凯氏定氮法测定全氮,钼锑钪比色法测定全磷,火焰光度计法测定全钾[28]。可溶性糖类用乙醇在80 ℃下萃取后用蒽酮硫酸法测定[29];将提取可溶性糖后的残渣用高氯酸水解,用蒽酮硫酸法测定淀粉。
苗木质量指数综合评定[30]采用模糊数学隶属函数公式进行定量转换,随后将各隶属函数取均值再比较排序。具体公式为:
U(Xi)=(Xi−Xmin (1) 式中:U(Xi)为隶属函数值,Xi为某项测量指标,Xmin、Xmax分别为某一测量指标的最小值和最大值。
与综合评判结果呈负相关的指标则采用反隶属函数公式进行定量转换:
U(X_{i})=1-[(X_{i}-X_{\min})/(X_{\max}-X_{\min})] (2) 1.4 数据分析
试验数据采用Microsoft excel 2013记录和计算,origin 2018软件作图,SPSS 25.0对试验数据进行one-way ANOVA方差分析,如果处理间差异显著,则采用Duncan法在0.05水平上进行多重比较。苗木方程拟合和生长阶段的划分参考崔党群[31]的研究,拟合方程为:
y=\dfrac{k}{(1 + {a\mathrm{e}}^{-bt})} ,通过计算得到最大相对生长速率(Vm)、时间(Tm)、苗木速生起始时间(t1)、速生结束时间(t2)、速生期持续时间(T = t2 − t1)、速生期生长速率(Vt)以及速生期生长量(Lg)。2. 结果与分析
2.1 不同土壤水势对毛白杨苗木苗高、地径年生长过程的影响
移植后0 ~ 30 d,由于初期漫灌影响,不同水势处理下苗木苗高无显著差异(P > 0.05)(表1)。自移栽45 d起,不同处理间苗高、地径差异显著(P < 0.05),且随灌溉水平增加而增大,苗木休眠前,A处理苗高、地径显著高于其他处理,且分别较CK高34.33%、40.35%。说明A处理显著促进了苗高和地径的生长,使苗木提前开始快速生长。同时,移植后至45 d,C处理苗高与CK差异不显著(P > 0.05),但休眠前C处理苗高生长显著大于CK12.35%;从地径生长来看,移植后至45 d,CK地径显著高于C处理(P < 0.05),移植后60 ~ 130 d,二者地径差异不显著,但170 d后C处理地径显著高于CK7.66%。说明灌溉的效果在缓苗阶段作用不明显,但会随时间推移逐渐显现。
表 1 不同土壤水势下毛白杨苗木苗高、地径生长过程表现Table 1. Growth process of seedling height and ground diameter of Populus tomentosaseedlings under different soil water potentials移栽后天数
Days after transplanting苗高 Seedling height/cm 地径 Root collar diameter (RCD) /mm A B C CK A B C CK 0 13.57 ± 1.52a 13.57 ± 1.52a 13.57 ± 1.52a 13.57 ± 1.52a 2.95 ± 0.33a 2.95 ± 0.33a 2.95 ± 0.33a 2.95 ± 0.33a 30 26.59 ± 3.95a 26.53 ± 2.58a 26.83 ± 3.78a 26.04 ± 4.10a 4.21 ± 0.57a 4.27 ± 0.37a 3.89 ± 0.35b 4.06 ± 0.46ab 45 60.75 ± 9.17a 56.56 ± 5.71b 55.18 ± 4.18bc 52.82 ± 6.87c 6.78 ± 1.00a 6.75 ± 0.56a 5.66 ± 0.45c 6.07 ± 0.66b 60 118.51 ± 15.10a 101.69 ± 11.50b 88.27 ± 8.44c 78.23 ± 8.48d 9.41 ± 0.96a 8.82 ± 0.74b 7.53 ± 0.64c 7.77 ± 0.91c 75 182.96 ± 20.12a 160.99 ± 14.55b 129.80 ± 11.54c 127.67 ± 15.31c 15.79 ± 2.02a 13.61 ± 1.46b 11.35 ± 1.22c 11.63 ± 1.28c 100 233.31 ± 19.66a 213.63 ± 19.41b 185.11 ± 14.85c 171.12 ± 18.86d 20.09 ± 2.48a 18.06 ± 1.88b 15.05 ± 1.44c 14.91 ± 1.65c 115 289.30 ± 22.00a 268.79 ± 19.33b 235.22 ± 18.09c 219.25 ± 21.59d 23.96 ± 2.53a 21.96 ± 1.95b 18.24 ± 1.80c 18.59 ± 2.18c 130 347.75 ± 24.56a 332.14 ± 22.15b 298.81 ± 23.93c 264.54 ± 24.97d 27.58 ± 2.99a 24.53 ± 2.31b 21.08 ± 2.13c 20.30 ± 2.43c 147 372.43 ± 24.61a 353.15 ± 23.84b 319.31 ± 24.52c 284.39 ± 27.31d 28.23 ± 3.21a 25.41 ± 2.07b 22.16 ± 2.26c 20.96 ± 2.67d 170 399.00 ± 24.77a 370.38 ± 24.97b 337.67 ± 25.38c 297.00 ± 32.11d 29.94 ± 3.57a 26.80 ± 2.40b 23.25 ± 2.38c 21.57 ± 2.87d 195 399.00 ± 24.77a 370.38 ± 24.97b 337.67 ± 25.38c 297.00 ± 32.11d 31.13 ± 3.70a 27.66 ± 1.92b 23.80 ± 2.20c 22.18 ± 2.93d 220 399.00 ± 24.77a 370.38 ± 24.97b 337.67 ± 25.38c 297.00 ± 32.11d 31.13 ± 3.70a 27.66 ± 1.92b 23.80 ± 2.20c 22.18 ± 2.93d 注:A、B、C分别代表3种不同灌溉起始阈值,CK为对照。小写字母为Duncan多重比较结果,同行相同字母表示不同处理间差异不显著,不同字母表示差异显著(P < 0.05)。下同。Notes: A, B and C represent three different irrigation threshold values, respectively, CK means control. Lowercase letters are Duncan multiple comparison results, the same letter in the same row indicates that the difference between varied treatments is not significant, and different letters indicate that the difference is significant (P < 0.05). The same below. 从毛白杨苗木苗高和地径净增长量(图1)可以看出,毛白杨苗木生长期较长,约为220 d,且不同灌溉水平处理下,苗木苗高、地径生长峰的出现时间存在差异。除CK外,各处理生长期内苗高均出现2个生长峰。A、B处理与CK第一苗高生长峰出现时间相同,为栽植后75 d,CK的60 ~ 75 d净生长量为49.44 cm,占全年生长量16.62%,A、B处理60 ~ 75 d的净生长量分别为64.45和59.30 cm,占全年生长量的17.28%和16.77%,比CK分别高出30.60%和19.94%。C处理苗高第一生长峰较其他处理延迟了约25 d,75 ~ 101 d净生长量占全年生长量16.88%。相较于常规灌溉处理的CK,各灌溉处理下苗木的第二个苗高生长高峰出现在9月上旬,约移植后130 d,生长量为全年生长量14.54% ~ 18.66%,随后苗高生长逐渐减缓直至停止。
各处理整个生长期内的地径生长只出现一个高峰,且与第一个苗高高峰时间相同,即移苗后第75 d,其中A处理60 ~ 75 d的净生长量最大,较CK高出65.29%,此后地径生长速度逐渐减缓直至停止;116 d时,CK出现地径第二生长峰,101 ~ 116 d的净增长量为3.68 mm,占全年生长量18.87%。整体来看,苗高和地径生长持续时间有一定差异,苗高生长在移植后约197 d后逐渐停止,而地径净增长量则持续至约220 d,说明秋季苗木高生长停止后,地径仍会有一段时间的缓慢增长。
2.2 不同土壤水势下毛白杨苗木年生长模型的建立
根据拟合方程建立苗高、地径的Logistic生长曲线(图2),拟合方程及方差分析结果见表2。如图表所示,所有处理的苗高、地径的增长曲线均为“S”型,呈现明显的“慢—快—慢”的规律。各处理的实际观测值和理论值拟合较好,苗高、地径Logistic方程拟合回归关系达到极显著水平(P < 0.001),R2在0.993 ~ 0.997间。预测苗高生长曲线在移植后175 d趋于平稳,而地径生长则在195 d后逐渐平稳,与实际观测结果基本一致,说明用拟合方程的理论值估测实际值是可行的。
表 2 不同灌溉水平下毛白杨苗木苗高、地径Logistic方程及回归假设检验Table 2. Logistic equations of P. tomentosa seedling height, RCD underdifferent water conditions and the regression test指标
Index处理
Treatment回归方程
Regression equationR2 P 苗高
Seedling heightA y = 409.178/(1 + 30.569exp(−0.038x)) 0.993 < 0.001 B y = 380.379/(1 + 30.022exp(−0.039x)) 0.994 < 0.001 C y = 349.519/(1 + 30.081exp(−0.037x)) 0.994 < 0.001 CK y = 305.991/(1 + 28.810exp(−0.038x)) 0.995 < 0.001 地径
Root coolar diameterA y = 31.683/(1 + 17.074exp(−0.035x)) 0.995 < 0.001 B y = 28.212/(1 + 14.903exp(−0.034x)) 0.997 < 0.001 C y = 24.539/(1 + 13.899exp(−0.032x)) 0.995 < 0.001 CK y = 22.694/(1 + 12.412exp(−0.034x)) 0.993 < 0.001 2.3 不同土壤水势对毛白杨苗木生长节律的影响
参考郭欢欢等[32]对黄连木(Pistacia chinensis)一年生实生苗生长节律的研究方法,根据新叶生长时间,确定苗木的成活期为移植后至15 d,并结合Logistic回归方程计算出生长拐点t1、t2以及速生期持续时间T(表3),t1之前为生长初期,t2之后为木质化期,二者之间为速生期,因而可以在理论上根据苗高生长将毛白杨苗木生长期划分为4个生长阶段。第1阶段为成活期:从移苗至移苗后15 d(苗木长出3 ~ 5片新叶);第2阶段为生长初期:移苗后16 ~ 53 d;第3阶段为速生期:为移苗后53 ~ 138 d;第4阶段为木质化期:为移苗后139 ~ 220 d。
表 3 不同灌溉水平下毛白杨苗木苗高、地径生长节律参数Table 3. Growth rhythm parameters of seedling height and RCD of P. tomentosa处理
Treatment苗高生长节律
Seedling height growth rhythm地径生长节律
RCD growth rhythmt1/d t2/d T/d Tm/d Vm/(cm·d−1) Vt/(cm·d−1) Lg/cm t1/d t2/d T/d Tm/d Vm/(mm·d−1) Vt/(mm·d−1) Lg/mm A 52 149 92 86 3.77 3.31 253.38 43 140 97 81 0.28 0.24 21.38 B 54 148 94 87 3.60 3.16 239.15 41 139 98 82 0.23 0.21 19.63 C 55 147 92 92 3.22 2.83 221.38 41 134 93 82 0.20 0.17 17.96 CK 53 138 85 88 2.82 2.47 198.65 35 128 93 76 0.19 0.16 14.63 注:t1、t2分别为速生期开始和结束时间,T为速生期持续时间,Tm为速生期最大生长速率出现时间;Vm、Vt分别为速生期最大生长速率和速生期平均生长速率,Lg为速生期增长量。Notes: t1, t2, T and Tm represent start time, end time, length of fast growing phase and the maximum growth rate appear time, respectively. Vm, Vt, Lg mean the maximum growth rate, average growth rate and increment at fast growing phase, respectively. 速生期灌溉对毛白杨苗木速生期开始时间的影响不显著(P > 0.05),各处理苗木速生期均开始于移植后约53 d。常规漫灌下苗木的苗高速生期持续时间约85 d,较地径速生期的持续时间短约8 d,其中高灌溉水平的A处理苗高、地径速生期持续时间比CK长7和4 d。速生期灌溉同样显著影响着苗木在速生期的最大生长速率、平均生长速率和生长量(P < 0.05),三者均随灌溉水平的升高而增大,其中A处理苗高和地径的最大生长速率最大,分别高于CK下苗木33.70%、47.59%。说明速生期灌溉对毛白杨苗木生长的促进效果,主要表现在提高速生期生长速率的同时延长了速生期的持续时间,从而使生长量显著增加。
2.4 不同土壤水势对毛白杨苗木形态特征与生物量分配的影响
不同土壤水势条件下苗高、地径差异显著(P < 0.05)(表4),随灌溉起始阈值升高,二者显著增大,其中A处理的苗高、地径、茎生物量和根生物量最大,较CK分别高出34.34%、40.35%、176.17%和157.17%。从苗木的生物量分配来看,苗高与茎生物量、地径与根生物量有着显著的正相关关系(P < 0.05)。CK生物量最小,B、C处理的茎根比显著高于A处理和CK(P < 0.05),分别比CK高出30.34%和35.86%,说明灌溉显著提高了苗木的生长量并影响着生物量的分配。总体来看,随灌溉起始阈值升高,苗木会分配更多生物量给茎,但达到一定阈值时,会重新倾向于分配给根系,这可能是由于CK的苗木处于低水分的胁迫状态,从而使根系生物量增加。
表 4 毛白杨苗木形态特征和生物量分配Table 4. Seedling morphology parameters and biomass allocation of P. tomentosa seedlings处理
Treatment苗高 Seedling height/cm 地径
RCD/mm苗高/地径
Seedling height/ RCD茎生物量
Stem biomass/g根生物量
Root biomass/g茎根比
Shoot/root苗高−茎生物量
相关系数
Seedling height-stem
biomass correlation
coefficient地径−根生物量
相关系数
RCD- root
biomass correlation
coefficientA 399.00 ± 24.77a 31.13 ± 3.70a 12.92 ± 0.97c 456.89 ± 59.36a 302.33 ± 88.36a 1.57 ± 0.22b 0.852** 0.709* B 370.38 ± 24.97b 27.66 ± 1.92b 13.41 ± 0.68b 313.67 ± 77.29b 160.88 ± 37.12b 1.97 ± 0.38a 0.927** 0.941** C 337.67 ± 25.38c 23.80 ± 2.20c 14.23 ± 0.77a 244.33 ± 55.43c 132.67 ± 39.56b 1.89 ± 0.23a 0.892* 0.918** CK 297.00 ± 32.11d 22.18 ± 2.93d 13.45 ± 0.78b 165.44 ± 45.19d 117.56 ± 38.58b 1.61 ± 0.28b 0.889* 0.767* 注:*表示相关性显著(P < 0.05),**表示相关性极显著(P < 0.01)。Notes: * means significant correlation (P < 0.05), ** means extremely significant correlation( P < 0.01). 2.5 不同土壤水势对毛白杨苗木养分质量分数的影响
不同土壤水势对苗木茎中氮(N)及根中N、磷(P)、钾(K)养分的质量分数影响显著(P < 0.05)。多重比较结果表明(表5),A处理茎中N和可溶性糖质量分数最低,分别显著低于其他处理约12.39% ~ 14.36%、43.22% ~ 51.64%。各处理根系中各养分质量分数差异显著(P < 0.05),其中CK最大,显著高于各处理15.14% ~ 44.29%。根中N质量分数随土壤水势升高逐渐降低,其中A处理最小,较CK低9.86%;P、K、淀粉及可溶性糖变化规律相似,均随灌溉起始阈值的升高呈现先降低后升高的趋势。
表 5 不同土壤水势下毛白杨苗木各器官矿质养分和非结构性碳质量分数Table 5. Seedling mineral nutrients and non-structural carbohydrate concentration of P. tomentosa seedlings under different soil water potentials% 组织
Tissue养分
Nutrient处理 Treatment A B C CK 茎 Stem N 1.428 ± 0.047b 1.631 ± 0.084a 1.605 ± 0.045a 1.633 ± 0.09a P 0.099 ± 0.002a 0.102 ± 0.013a 0.097 ± 0.021a 0.109 ± 0.003a K 0.253 ± 0.056a 0.270 ± 0.014a 0.283 ± 0.025a 0.273 ± 0.023a 淀粉 Starch 2.449 ± 0.391a 2.582 ± 0.338a 2.407 ± 0.264a 2.515 ± 0.366a 可溶性糖 Soluble sugar 4.239 ± 0.162b 6.428 ± 0.411a 6.071 ± 1.122a 6.124 ± 1.628a 根 Root N 1.745 ± 0.055b 1.762 ± 0.094b 1.771 ± 0.076b 1.917 ± 0.086a P 0.175 ± 0.005ab 0.156 ± 0.023b 0.157 ± 0.007b 0.204 ± 0.022a K 0.452 ± 0.021b 0.508 ± 0.071ab 0.469 ± 0.062b 0.604 ± 0.041a 淀粉 Starch 6.645 ± 0.698b 5.607 ± 0.271c 6.280 ± 0.272b 8.274 ± 0.526a 可溶性糖 Soluble sugar 17.172 ± 2.212ab 16.412 ± 2.412bc 13.703 ± 2.187c 19.772 ± 2.329a 2.6 不同土壤水势对毛白杨苗木养分单株质量的影响
土壤水势显著影响毛白杨苗木养分单株质量(P < 0.05),随土壤水势阈值降低,苗木各养分单株质量呈下降趋势,其中−20 kPa处理单株养分质量最大,显著高于其他处理43.83% ~ 130.21%。多重比较结果显示(图3),苗木根、茎中矿质元素养分单株质量差异显著(P < 0.05),各处理茎中N、P、K单株质量随土壤水势升高而升高,−20 kPa处理茎中矿质养分单株质量最大,分别高于CK100.08%、211.11%、160.00%。根中矿质养分单株质量变化规律不明显,除−20 kPa处理外,其余各处理与CK差异不显著,但均显著低于−20 kPa处理85.71% ~ 90.00%。
图 3 不同水势下毛白杨苗木矿质养分和非结构性碳单株质量大写字母与小写字母为Duncan多重比较结果,不同字母表示差异显著(P < 0.05)。Capital letters and lowercase letters are Duncan’s multiple comparison results, and different letters indicate significant differences (P < 0.05).Figure 3. Seedling mineral nutrients and non-structural carbohydrate mass of P. tomentosa seedlings under different soil water potentials−20 kPa处理和−40 kPa处理茎中可溶性糖单株质量最大,显著高于CK237.51%;茎中淀粉单株质量随水势降低显著减少(P < 0.05),CK最小,显著低于各处理20.03% ~ 133.33%。−20 kPa处理根中淀粉和可溶性糖单株质量最大,显著高于其他处理60.06% ~ 79.64%,其余各处理与CK差异不显著。
2.7 苗木质量指数综合评定
苗木质量是一个综合的概念,单独用一个或孤立的几个指标很难真实反映。因此采用模糊数学隶属度公式对各项指标进行转换,用每个水势处理下各指标隶属度均值作为苗木质量综合评定标准。如表6所示:A处理苗木质量最佳,隶属度均值在0.6以上;C处理和CK苗木质量中等,隶属度均值在0.5以上。除茎根比,N、K、可溶性糖质量分数及可溶性糖单株质量外,各项指标的隶属度与综合值相关系数均在0.7以上,有着较好的相关性,因此可将这些指标用于毛白杨苗木质量的综合评定。
表 6 苗木质量指数综合评价Table 6. Comprehensive evaluation of seedling quality index处理
Treatment苗高
Seedling height地径
RCD生物量
Biomass茎根比
Shoot/
root养分质量分数 Nutrient mass fraction 养分单株质量 Nutrient mass per plant 综合结果
Comprehensive
result位次
RankingN P K 淀粉 Starch 可溶性糖
Soluble
sugarN P K 淀粉 Starch 可溶性糖
Soluble
sugarA 0.485 0.475 0.718 0.622 0.601 0.500 0.530 0.573 0.497 0.719 0.720 0.720 0.721 0.722 0.615 1 B 0.501 0.503 0.575 0.587 0.498 0.378 0.450 0.522 0.394 0.378 0.403 0.418 0.429 0.449 0.463 4 C 0.533 0.461 0.628 0.441 0.357 0.423 0.500 0.450 0.214 0.628 0.629 0.628 0.629 0.629 0.511 2 CK 0.541 0.595 0.492 0.385 0.388 0.568 0.620 0.474 0.480 0.512 0.517 0.519 0.522 0.522 0.510 3 相关系数Correlation coefficient 0.944 0.963 0.732 0.494 0.568 0.995 0.585 0.806 0.503 0.773 0.704 0.757 0.646 0.770 0.731 3. 讨 论
3.1 不同土壤水势对毛白杨苗木生长节律的影响
通过Logistic方程拟合植物生长节律并估算相关参数[33],可以研究栽培措施对苗木生长的影响。本试验与前人对米老排(Mytilaria laosensis)[34]、文冠果(Xanthoceras sorbifolium)[35]、浙江樟(Cinnamomum chekiangense)[36]等树种的研究结果相似,苗木生长的Logistic方程拟合效果较好,回归关系均高于0.993,达到极显著水平,且与实际观测值接近。此外,所有处理下苗木苗高与茎生物量、地径与根生物量间存在显著的正相关关系,这与郭欢欢[32]对黄连木苗木、纪晓婷[37]对夏蜡梅(Sinocalycanthus chinensis)苗木的研究结果相似。这表明今后可采用Logistic生长模型对毛白杨苗木生长过程进行精准预测和分析,并测量苗木的苗高和地径,估算苗木各部分生物量,为苗期科学管理提供参考。
进行苗木生长节律拟合后通过计算可以划分相应的生长阶段,这有利于对苗木进行精准灌溉[4]。本试验中,根据对毛白杨苗木高生长的实际观测和Logistic方程拟合结果,可以将毛白杨1年生苗木的生长阶段划分为4个时期:成活期,移苗至移苗后第15 d;生长初期,移苗后16 ~ 53 d;速生期,移苗后54 ~ 138 d;木质化期,移苗后139 ~ 220 d。成活期和生长初期苗木较为幼嫩,应当注意进行保护,而苗木的速生期持续时间仅为整个生长期的37.37%,但生长量占总生长量65.72%以上,是苗木生长的关键阶段,应当加强田间管理,配合施肥等促进苗木生长。而在木质化期则应适度控水以促进苗木木质化,提高其抗寒能力[4]。
具体来看,水分对毛白杨苗木生长的影响是一个动态的过程[7],影响了生长峰的持续时间和生长量。速生期前−20 kPa处理的形态指标显著高于常规灌溉31.82%,木质化期前则可达34.33%。生长季内所有处理下苗木的苗高均会出现两个生长峰,但−60 kPa处理下的第一生长峰比其他处理晚25 d,常规灌溉处理的第二生长峰则会提前约16 d;各水势处理下苗木的地径在生长季内只有一个生长峰,但常规灌溉在116 d时会出现地径第二生长峰,这与韩立新等[38]对梨枣(Ziziphus jujuba)的研究结果相似,表明苗木在不同生长阶段对土壤水势的响应是不同的,生长峰出现次数和时间可能存在差异。此外,各处理下苗木的苗高速生期开始时间、持续时间没有显著差异,但常规漫灌处理下的地径速生期开始时间和持续时间显著短于其他处理约5 d,由此可见,土壤水势的变化并不会影响苗木在速生期高生长的持续时间[39]。
此外,本试验中土壤水势的变化显著影响着苗木在速生期的生长速率,随土壤水势的增加,苗木在速生期的苗高、地径生长速率显著增加,这与对扁桃树(Amygdalus communis)[40]和山杨[41]的研究结果相似。而前人对落叶松(Larix gmelinii)[42]研究发现,落叶松苗木速生期土壤最佳水势为−10 ~ −20 kPa,葡萄(Vitis vinifera)生长期土壤灌溉起始阈值则在−10 ~ −30 kPa间[43]。本研究结果与之相似,毛白杨苗木在土壤水势为−20 kPa时生长最佳,苗木在速生期的苗高、地径生长速率最大,显著高于常规灌溉30.51% ~ 47.6%,这可能是因为灌溉影响了土壤水分有效性,进而影响了苗木的光合速率、水分利用效率和生长速率[44-45],从而促进了苗木的生长。因此从苗木生长速率和形态指标来考虑,育苗时以−20 kPa作为灌溉起始阈值最佳。
3.2 不同土壤水势对毛白杨苗木质量的影响
水分是影响毛白杨生长的最主要因素,直接影响着苗木的生长代谢[46]。与Shock[47]、Xi[48]、He[13]等对杨树人工林的研究结果相似,土壤水势的增加显著促进了毛白杨苗木苗高、地径的生长,其中最高水势阈值处理(−20 kPa)对应的苗高、地径较其他处理显著提高了12.55% ~ 34.33%和7.73% ~ 18.16%。本试验中随水势增加,苗木茎根比先增大后减小,−20 kPa处理培育出的苗木根茎比优于−40 kPa和−60 kPa处理,对山杨的研究中发现,茎根比的减小意味着相对更为发达的根系和更强的逆境适应能力[49],因此−20 kPa培育出的苗木可能在造林后的水分吸收和地上部分的养分供给更好,能有效的提高困难立地下的造林成功率。此外,各灌溉处理下的苗木的生物量随土壤水势升高显著增大,其中−20 kPa处理最大,较CK显著提高165.68%,这与黄国伟等[50]对楸树(Catalpa bungei)苗木、董雯怡等[25]对毛白杨‘S86’苗木研究结果相似,高水分处理下的苗木有着更大的生物量。作为植物光合产物积累的结果,生物量的大小影响着造林后苗木成活和生长发育状况[51-52],因此−20 kPa处理下苗木的更大生物量可能意味着更好的造林表现。
从苗木养分状况来看,本试验中−20 kPa处理下苗木茎中的N和可溶性糖质量分数显著低于其他各处理,这可能是快速生长引起的养分稀释作用导致的[8]。与陈闯等[10]对栓皮栎苗木研究结果不同,本试验中随土壤水势升高,地上部分生长加快,根系各养分质量分数反而逐渐降低,其中常规灌溉下苗木各养分质量分数显著高于各水势处理15.14% ~ 46.43%,这与对美洲山杨[36]的研究结果相似。但Sloan等[8]发现,在山杨苗木移苗后的早期便开始控水,低水势处理下苗木茎中可溶性糖和淀粉质量分数显著低于高水分处理,这与本试验结果存在差异,因此后期可以针对不同灌溉时间进行试验设计。常规灌溉相较于各水势处理有着更高的可溶性糖和K质量分数,这可能意味着常规灌溉下苗木具有更好的抗性[53-54]。可见苗圃培育措施能够增加苗木的可溶性糖质量分数,这可能有利于苗木造林后的表现[49],但仍然需要进一步的造林试验对苗木质量及适用范围进行检验[55]。
从苗木质量综合评定结果来看,−20 kPa处理培育的苗木评定结果最好,苗木质量最佳,可以作为条件相似地区育苗时的灌溉参考阈值。此外,可将除茎根比和N、K、可溶性糖质量分数及可溶性糖单株质量外的指标用于毛白杨苗木质量的评定。但毛白杨分布范围较广,本次试验仅开展于黄河中下游平原地区,因而需要进一步的育苗试验和造林试验验证后方可在其他适生区进行推广。
4. 结 论
(1)根据苗高生长可以将1年生毛白杨苗木的生长期划分为4个阶段:成活期,移苗至移苗后第15 d;生长初期,移苗后16 ~ 53 d;速生期,移苗后54 ~ 138 d;木质化期,移苗后139 ~ 220 d。
(2)采用Logistic方程可以较好的拟合毛白杨苗木苗高和地径的生长,R2在0.993 ~ 0.997间,回归关系达到极显著水平,且与实测数据相差不大,因此可以采用Logistic模型对毛白杨苗木的生长进行预测。同时毛白杨苗木的苗高与茎生物量、地径与根生物量之间存在显著正相关关系,可以通过苗高和地径的测量值对苗木茎和根的生物量进行估算。
(3)土壤水势的增加显著促进了毛白杨苗木苗高、地径的生长,以−20 kPa作为灌溉起始阈值时苗木各形态指标最佳,苗木的苗高、地径、茎生物量和根生物量较常规灌溉提高了34.33%、40.35%、176.17%和157.17%,且较−40 kPa和−60 kPa处理下的苗木有着更佳的茎根比。
(4)土壤水势的增加显著提高了毛白杨苗木的养分单株质量,−20 kPa处理下苗木各养分单株质量最大,其中矿质养分单株质量高于常规灌溉100.08% ~ 211.11%,非结构性碳单株质量高于常规灌溉133.33% ~ 237.51%。
(5)从苗木质量指数综合评定结果来看,以−20 kPa作为速生期灌溉起始阈值时苗木质量最佳,可以在与育苗地环境条件相似的地区进行推广。
-
图 3 不同水势下毛白杨苗木矿质养分和非结构性碳单株质量
大写字母与小写字母为Duncan多重比较结果,不同字母表示差异显著(P < 0.05)。Capital letters and lowercase letters are Duncan’s multiple comparison results, and different letters indicate significant differences (P < 0.05).
Figure 3. Seedling mineral nutrients and non-structural carbohydrate mass of P. tomentosa seedlings under different soil water potentials
表 1 不同土壤水势下毛白杨苗木苗高、地径生长过程表现
Table 1 Growth process of seedling height and ground diameter of Populus tomentosaseedlings under different soil water potentials
移栽后天数
Days after transplanting苗高 Seedling height/cm 地径 Root collar diameter (RCD) /mm A B C CK A B C CK 0 13.57 ± 1.52a 13.57 ± 1.52a 13.57 ± 1.52a 13.57 ± 1.52a 2.95 ± 0.33a 2.95 ± 0.33a 2.95 ± 0.33a 2.95 ± 0.33a 30 26.59 ± 3.95a 26.53 ± 2.58a 26.83 ± 3.78a 26.04 ± 4.10a 4.21 ± 0.57a 4.27 ± 0.37a 3.89 ± 0.35b 4.06 ± 0.46ab 45 60.75 ± 9.17a 56.56 ± 5.71b 55.18 ± 4.18bc 52.82 ± 6.87c 6.78 ± 1.00a 6.75 ± 0.56a 5.66 ± 0.45c 6.07 ± 0.66b 60 118.51 ± 15.10a 101.69 ± 11.50b 88.27 ± 8.44c 78.23 ± 8.48d 9.41 ± 0.96a 8.82 ± 0.74b 7.53 ± 0.64c 7.77 ± 0.91c 75 182.96 ± 20.12a 160.99 ± 14.55b 129.80 ± 11.54c 127.67 ± 15.31c 15.79 ± 2.02a 13.61 ± 1.46b 11.35 ± 1.22c 11.63 ± 1.28c 100 233.31 ± 19.66a 213.63 ± 19.41b 185.11 ± 14.85c 171.12 ± 18.86d 20.09 ± 2.48a 18.06 ± 1.88b 15.05 ± 1.44c 14.91 ± 1.65c 115 289.30 ± 22.00a 268.79 ± 19.33b 235.22 ± 18.09c 219.25 ± 21.59d 23.96 ± 2.53a 21.96 ± 1.95b 18.24 ± 1.80c 18.59 ± 2.18c 130 347.75 ± 24.56a 332.14 ± 22.15b 298.81 ± 23.93c 264.54 ± 24.97d 27.58 ± 2.99a 24.53 ± 2.31b 21.08 ± 2.13c 20.30 ± 2.43c 147 372.43 ± 24.61a 353.15 ± 23.84b 319.31 ± 24.52c 284.39 ± 27.31d 28.23 ± 3.21a 25.41 ± 2.07b 22.16 ± 2.26c 20.96 ± 2.67d 170 399.00 ± 24.77a 370.38 ± 24.97b 337.67 ± 25.38c 297.00 ± 32.11d 29.94 ± 3.57a 26.80 ± 2.40b 23.25 ± 2.38c 21.57 ± 2.87d 195 399.00 ± 24.77a 370.38 ± 24.97b 337.67 ± 25.38c 297.00 ± 32.11d 31.13 ± 3.70a 27.66 ± 1.92b 23.80 ± 2.20c 22.18 ± 2.93d 220 399.00 ± 24.77a 370.38 ± 24.97b 337.67 ± 25.38c 297.00 ± 32.11d 31.13 ± 3.70a 27.66 ± 1.92b 23.80 ± 2.20c 22.18 ± 2.93d 注:A、B、C分别代表3种不同灌溉起始阈值,CK为对照。小写字母为Duncan多重比较结果,同行相同字母表示不同处理间差异不显著,不同字母表示差异显著(P < 0.05)。下同。Notes: A, B and C represent three different irrigation threshold values, respectively, CK means control. Lowercase letters are Duncan multiple comparison results, the same letter in the same row indicates that the difference between varied treatments is not significant, and different letters indicate that the difference is significant (P < 0.05). The same below. 表 2 不同灌溉水平下毛白杨苗木苗高、地径Logistic方程及回归假设检验
Table 2 Logistic equations of P. tomentosa seedling height, RCD underdifferent water conditions and the regression test
指标
Index处理
Treatment回归方程
Regression equationR2 P 苗高
Seedling heightA y = 409.178/(1 + 30.569exp(−0.038x)) 0.993 < 0.001 B y = 380.379/(1 + 30.022exp(−0.039x)) 0.994 < 0.001 C y = 349.519/(1 + 30.081exp(−0.037x)) 0.994 < 0.001 CK y = 305.991/(1 + 28.810exp(−0.038x)) 0.995 < 0.001 地径
Root coolar diameterA y = 31.683/(1 + 17.074exp(−0.035x)) 0.995 < 0.001 B y = 28.212/(1 + 14.903exp(−0.034x)) 0.997 < 0.001 C y = 24.539/(1 + 13.899exp(−0.032x)) 0.995 < 0.001 CK y = 22.694/(1 + 12.412exp(−0.034x)) 0.993 < 0.001 表 3 不同灌溉水平下毛白杨苗木苗高、地径生长节律参数
Table 3 Growth rhythm parameters of seedling height and RCD of P. tomentosa
处理
Treatment苗高生长节律
Seedling height growth rhythm地径生长节律
RCD growth rhythmt1/d t2/d T/d Tm/d Vm/(cm·d−1) Vt/(cm·d−1) Lg/cm t1/d t2/d T/d Tm/d Vm/(mm·d−1) Vt/(mm·d−1) Lg/mm A 52 149 92 86 3.77 3.31 253.38 43 140 97 81 0.28 0.24 21.38 B 54 148 94 87 3.60 3.16 239.15 41 139 98 82 0.23 0.21 19.63 C 55 147 92 92 3.22 2.83 221.38 41 134 93 82 0.20 0.17 17.96 CK 53 138 85 88 2.82 2.47 198.65 35 128 93 76 0.19 0.16 14.63 注:t1、t2分别为速生期开始和结束时间,T为速生期持续时间,Tm为速生期最大生长速率出现时间;Vm、Vt分别为速生期最大生长速率和速生期平均生长速率,Lg为速生期增长量。Notes: t1, t2, T and Tm represent start time, end time, length of fast growing phase and the maximum growth rate appear time, respectively. Vm, Vt, Lg mean the maximum growth rate, average growth rate and increment at fast growing phase, respectively. 表 4 毛白杨苗木形态特征和生物量分配
Table 4 Seedling morphology parameters and biomass allocation of P. tomentosa seedlings
处理
Treatment苗高 Seedling height/cm 地径
RCD/mm苗高/地径
Seedling height/ RCD茎生物量
Stem biomass/g根生物量
Root biomass/g茎根比
Shoot/root苗高−茎生物量
相关系数
Seedling height-stem
biomass correlation
coefficient地径−根生物量
相关系数
RCD- root
biomass correlation
coefficientA 399.00 ± 24.77a 31.13 ± 3.70a 12.92 ± 0.97c 456.89 ± 59.36a 302.33 ± 88.36a 1.57 ± 0.22b 0.852** 0.709* B 370.38 ± 24.97b 27.66 ± 1.92b 13.41 ± 0.68b 313.67 ± 77.29b 160.88 ± 37.12b 1.97 ± 0.38a 0.927** 0.941** C 337.67 ± 25.38c 23.80 ± 2.20c 14.23 ± 0.77a 244.33 ± 55.43c 132.67 ± 39.56b 1.89 ± 0.23a 0.892* 0.918** CK 297.00 ± 32.11d 22.18 ± 2.93d 13.45 ± 0.78b 165.44 ± 45.19d 117.56 ± 38.58b 1.61 ± 0.28b 0.889* 0.767* 注:*表示相关性显著(P < 0.05),**表示相关性极显著(P < 0.01)。Notes: * means significant correlation (P < 0.05), ** means extremely significant correlation( P < 0.01). 表 5 不同土壤水势下毛白杨苗木各器官矿质养分和非结构性碳质量分数
Table 5 Seedling mineral nutrients and non-structural carbohydrate concentration of P. tomentosa seedlings under different soil water potentials
% 组织
Tissue养分
Nutrient处理 Treatment A B C CK 茎 Stem N 1.428 ± 0.047b 1.631 ± 0.084a 1.605 ± 0.045a 1.633 ± 0.09a P 0.099 ± 0.002a 0.102 ± 0.013a 0.097 ± 0.021a 0.109 ± 0.003a K 0.253 ± 0.056a 0.270 ± 0.014a 0.283 ± 0.025a 0.273 ± 0.023a 淀粉 Starch 2.449 ± 0.391a 2.582 ± 0.338a 2.407 ± 0.264a 2.515 ± 0.366a 可溶性糖 Soluble sugar 4.239 ± 0.162b 6.428 ± 0.411a 6.071 ± 1.122a 6.124 ± 1.628a 根 Root N 1.745 ± 0.055b 1.762 ± 0.094b 1.771 ± 0.076b 1.917 ± 0.086a P 0.175 ± 0.005ab 0.156 ± 0.023b 0.157 ± 0.007b 0.204 ± 0.022a K 0.452 ± 0.021b 0.508 ± 0.071ab 0.469 ± 0.062b 0.604 ± 0.041a 淀粉 Starch 6.645 ± 0.698b 5.607 ± 0.271c 6.280 ± 0.272b 8.274 ± 0.526a 可溶性糖 Soluble sugar 17.172 ± 2.212ab 16.412 ± 2.412bc 13.703 ± 2.187c 19.772 ± 2.329a 表 6 苗木质量指数综合评价
Table 6 Comprehensive evaluation of seedling quality index
处理
Treatment苗高
Seedling height地径
RCD生物量
Biomass茎根比
Shoot/
root养分质量分数 Nutrient mass fraction 养分单株质量 Nutrient mass per plant 综合结果
Comprehensive
result位次
RankingN P K 淀粉 Starch 可溶性糖
Soluble
sugarN P K 淀粉 Starch 可溶性糖
Soluble
sugarA 0.485 0.475 0.718 0.622 0.601 0.500 0.530 0.573 0.497 0.719 0.720 0.720 0.721 0.722 0.615 1 B 0.501 0.503 0.575 0.587 0.498 0.378 0.450 0.522 0.394 0.378 0.403 0.418 0.429 0.449 0.463 4 C 0.533 0.461 0.628 0.441 0.357 0.423 0.500 0.450 0.214 0.628 0.629 0.628 0.629 0.629 0.511 2 CK 0.541 0.595 0.492 0.385 0.388 0.568 0.620 0.474 0.480 0.512 0.517 0.519 0.522 0.522 0.510 3 相关系数Correlation coefficient 0.944 0.963 0.732 0.494 0.568 0.995 0.585 0.806 0.503 0.773 0.704 0.757 0.646 0.770 0.731 -
[1] 乌丽雅斯, 刘勇. 造林树种苗木定向培育理论探讨[J]. 北京林业大学学报, 2004, 26(4): 85−90. doi: 10.3321/j.issn:1000-1522.2004.04.018 Wuliyasi, Liu Y. Theories of directed seedling cultivation for reforestation varieties[J]. Journal of Beijing Forestry University, 2004, 26(4): 85−90. doi: 10.3321/j.issn:1000-1522.2004.04.018
[2] Grossnickle S C, MacDonald J E. Why seedlings grow: influence of plant attributes[J]. New Forests, 2018, 49(1): 1−34. doi: 10.1007/s11056-017-9606-4
[3] 李国雷, 刘勇, 祝燕, 等. 国外容器苗质量调控技术研究进展[J]. 林业科学, 2012, 48(8): 135−142. doi: 10.11707/j.1001-7488.20120822 Li G L, Liu Y, Zhu Y. A review on the abroad studies of techniques in regulating quality of container seedling[J]. Scientia Silvae Science, 2012, 48(8): 135−142. doi: 10.11707/j.1001-7488.20120822
[4] Dumroese R K, Landis T D, Pinto J R, et al. Meeting forest restoration challenges: using the target plant concept[J]. Reforesta, 2016, 1(1): 37−52.
[5] Haase D, Davis A. Developing and supporting quality nursery facilities and staff are necessary to meet global forest and landscape restoration needs[J]. Reforesta, 2017, 1(4): 69−93.
[6] Shi W H, Grossnickle S C, Li G L, et al. Fertilization and irrigation regimes influence on seedling attributes and field performance of Pinus tabuliformis Carr.[J]. Forestry, 2019, 92(1): 97−107. doi: 10.1093/forestry/cpy035
[7] Dumroese R K, Luna T, Landis T D. Nursery manual for native plants: a guide for tribal nurseries (Volume 1): nursery management[M]. Washington: Department of Agriculture, Forest Service, 2009.
[8] Sloan J L, Burney O T, Pinto J R. Drought-conditioning of quaking aspen (Populus tremuloides Michx.) seedlings during nursery production modifies seedling anatomy and physiology[J]. Frontiers in Plant Science, 2020, 11(4): 1−11.
[9] Dutra A F, Araujo M M, Tabaldi L A, et al. Optimization of water use in seedling production of arboreal species[J]. Cerne, 2018, 24(3): 201−208. doi: 10.1590/01047760201824032516
[10] 陈闯, 刘勇, 李国雷, 等. 底部渗灌灌水梯度对栓皮栎容器苗生长和养分状况的影响[J]. 林业科学, 2015, 51(7): 21−27. Chen C, Liu Y, Li G L, et al. Effects of sub-irrigation gradients on growth and nutrient status of containerized seedling of Quercus variabilis[J]. Scientia Silvae Science, 2015, 51(7): 21−27.
[11] Hansen E A. Irrigating short rotation intensive culture hybrid poplars[J]. Biomass, 1988, 16(4): 237−250. doi: 10.1016/0144-4565(88)90029-7
[12] Li D D, Fernández J E, Li X, et al. Tree growth patterns and diagnosis of water status based on trunk diameter fluctuations in fast-growing Populus tomentosa plantations[J/OL]. Agricultural Water Management, 2020, 241: 106348[2020−06−01]. https://doi.org/10.1016/j.agwat.2020.106348.
[13] He Y L, Xi B Y, Bloomberg M, et al. Effects of drip irrigation and nitrogen fertigation on stand growth and biomass allocation in young triploid Populus tomentosa plantations[J/OL]. Forest Ecology and Management, 2020. 461: 117937[2020−06−13]. https://doi.org/10.1016/j.foreco.2020.117937.
[14] 崔晓阳, 宋金凤, 张艳华. 不同土壤水势条件下水曲柳幼苗的光合作用特征[J]. 植物生态学报, 2004, 11(6): 794−802. doi: 10.3321/j.issn:1005-264X.2004.06.008 Cui X Y, Song J F, Zhang Y H. Some photosynthetic characteristics of Fraxinus mandshurica seedlings grown under different soil water potentials[J]. Acta Phytoecologica Sinica, 2004, 11(6): 794−802. doi: 10.3321/j.issn:1005-264X.2004.06.008
[15] 席本野, 王烨, 邸楠, 等. 地下滴灌下土壤水势对毛白杨纸浆林生长及生理特性的影响[J]. 生态学报, 2012, 32(17): 5318−5329. doi: 10.5846/stxb201203160352 Xi B Y, Wang Y, Di N, et al. Effects of soil water potential on the growth and physiological characteristics of Populus tomentosa pulpwood plantation under subsurface drip irrigation[J]. Acta Ecological Sinica, 2012, 32(17): 5318−5329. doi: 10.5846/stxb201203160352
[16] Lo B R, Francaviglia D. Comparative responses of ‘Gala’ and ‘Fuji’ apple trees to deficit irrigation: placement versus volume effects[J]. Plant and Soil, 2012, 357(1-2): 41−58. doi: 10.1007/s11104-012-1149-z
[17] Ballester C, Castel J, Intrigliolo D S, et al. Response of navel lane late citrus trees to regulated deficit irrigation: yield components and fruit composition[J]. Irrigation Science, 2013, 31(3): 333−341. doi: 10.1007/s00271-011-0311-3
[18] Grossnickle S C. Why seedlings survive: influence of plant attributes[J]. New Forests, 2012, 43(5−6): 711−738. doi: 10.1007/s11056-012-9336-6
[19] 康向阳. 新一轮毛白杨遗传改良策略的思考和实践[J]. 北京林业大学学报, 2016, 38(7): 1−8. Kang X Y. Thinking and practices for strategy on a new round genetic improvement of Populus tomentosa[J]. Journal of Beijing Forestry University, 2016, 38(7): 1−8.
[20] Dong W Y, Qin J, Li J Y, et al. Interactions between soil water content and fertilizer on growth characteristics and biomass yield of Chinese white poplar (Populus tomentosa Carr.) seedlings[J]. Soil Science and Plant Nutrition, 2011, 57(2): 303−312. doi: 10.1080/00380768.2010.549445
[21] 贺曰林, 王烨, 张宏锦, 等. 地表滴灌水氮耦合对毛白杨幼林生长及土壤水氮分布的影响[J]. 农业工程学报, 2018, 34(20): 90−98. doi: 10.11975/j.issn.1002-6819.2018.20.012 He Y L, Wang Y, Zhang H J, et al. Coupling effects of water and nitrogen on tree growth and soil water-nitrogen distribution in young populus tomentosa plantations under surface drip irrigation[J]. Transactions of the Chinese Society of Agricultural Engineering, 2018, 34(20): 90−98. doi: 10.11975/j.issn.1002-6819.2018.20.012
[22] 赵燕, 董雯怡, 张志毅, 等. 施肥对毛白杨杂种无性系幼苗生长和光合的影响[J]. 林业科学, 2010, 46(4): 70−77. doi: 10.11707/j.1001-7488.20100411 Zhao Y, Dong W Y, Zhang Z Y, et al. Effects of fertilization on seedling growth and photosynthesis of hybrid clone seedlings of Populus tomentosa[J]. Scientia Silvae Science, 2010, 46(4): 70−77. doi: 10.11707/j.1001-7488.20100411
[23] 何茜, 李吉跃, 陈晓阳, 等. 毛白杨不同无性系苗木耗水量及其昼夜分配[J]. 华南农业大学学报, 2010, 31(1): 47−50, 54. doi: 10.3969/j.issn.1001-411X.2010.01.012 He Q, Li J Y, Chen X Y, et al. Water utilization and its distribution in day and night in different Populus tomentosa clones[J]. Journal of South China Agricultural University, 2010, 31(1): 47−50, 54. doi: 10.3969/j.issn.1001-411X.2010.01.012
[24] 赵燕, 李彦娇, 李吉跃, 等. 氮、磷、钾对毛白杨无性系生长的影响[J]. 湖北农业科学, 2015, 54(5): 1130−1134. Zhao Y, Li Y J, Li J Y, et al. Effects of nitrogen, phosphorus and potassium on the growth of Populus tomentosa clone[J]. Hubei Agricultural Sciences, 2015, 54(5): 1130−1134.
[25] 董雯怡, 赵燕, 张志毅, 等. 水肥耦合效应对毛白杨苗木生物量的影响[J]. 应用生态学报, 2010, 21(9): 2194−2200. Dong W Y, Zhao Y, Zhang Z Y, et al. Coupling effects of water and fertilizer on the biomass of Populus tomentosa seedlings[J]. Chinese Journal of Applied Ecology, 2010, 21(9): 2194−2200.
[26] 裴保华. 毛白杨年生育规律的研究[J]. 林业科学, 1962, 2(4): 293−297. Pei B H. Study on annual growth rhythm of Populus tomentosa[J]. Scientia Silvae Science, 1962, 2(4): 293−297.
[27] Xi B Y, Li G D, Bloomberg M, et al. The effects of subsurface irrigation at different soil water potential thresholds on the growth and transpiration of Populus tomentosa in the North China Plain[J]. Australian Forestry, 2014, 77(3−4): 159−167. doi: 10.1080/00049158.2014.920552
[28] 鲍士旦. 土壤农化分析[M]. 北京: 农业出版社, 2005. Bao S D. Soil agrochemical analysis[M]. Beijing: Agricultural Publishing House, 2005.
[29] Spiro R G. Methods in enzymology [M]. New York: Academic Press, 1966.
[30] 刘勇, 陈艳, 张志毅, 等. 不同施肥处理对三倍体毛白杨苗木生长及抗寒性的影响[J]. 北京林业大学学报, 2000, 22(1): 38−44. doi: 10.3321/j.issn:1000-1522.2000.01.009 Liu Y, Chen Y, Zhang Z Y, et al. Effects of fertilizer treatments on seedling growth and cold resistance of triploid Populus tomentosa[J]. Journal of Beijing Forestry University, 2000, 22(1): 38−44. doi: 10.3321/j.issn:1000-1522.2000.01.009
[31] 崔党群. Logistic曲线方程的解析与拟合优度测验[J]. 数理统计与管理, 2005, 24(1): 112−115. doi: 10.3969/j.issn.1002-1566.2005.01.021 Cui D Q. Analysis and making good fitting degree test for Logistic curve regression equation[J]. Mathematical Statistics and Management, 2005, 24(1): 112−115. doi: 10.3969/j.issn.1002-1566.2005.01.021
[32] 郭欢欢, 刘勇, 姚飞, 等. 黄连木苗期年生长节律、生物量分配及养分积累[J]. 中南林业科技大学学报, 2018, 38(7): 71−75. Guo H H, Liu Y, Yao F, et al. Seedling growth rhythm, biomass allocation and nutrient accumulation of Pistacia chinensis[J]. Journal of Central South University of Forestry & Technology, 2018, 38(7): 71−75.
[33] 李峰卿, 姚甲宝, 曾平生. 光照强度和容器规格对纳塔栎1年生容器苗生长的影响[J]. 华南农业大学学报, 2017, 38(3): 87−92. doi: 10.7671/j.issn.1001-411X.2017.03.014 Li F Q, Yao J B, Zeng P S. Effects of light intensity and container size on growth of one-year-old seedlings of Quercus nuttallii[J]. Journal of South China Agricultural University, 2017, 38(3): 87−92. doi: 10.7671/j.issn.1001-411X.2017.03.014
[34] 覃敏, 尹天光, 杨锦昌, 等. 米老排不同种源苗期生长规律研究[J]. 中南林业科技大学学报, 2017, 37(1): 53−57. Qin M, Yin T G, Yang J C, et al. Growth pattern of Mytilaria laosensis seedlings from different provennaces[J]. Journal of Central South University of Forestry & Technology, 2017, 37(1): 53−57.
[35] 敖妍, 刘觉非, 陈浩, 等. 不同种源文冠果1年生苗生长节律及性状相关性研究[J]. 西北林学院学报, 2019, 34(3): 91−97. doi: 10.3969/j.issn.1001-7461.2019.03.14 Ao Y, Liu J F, Chen H, et al. Annual growth rhythm and character correlation analysis of 1-year-old Xanthoceras sorbifolium seedlings from different provenances[J]. Journal of Northwest Forestry University, 2019, 34(3): 91−97. doi: 10.3969/j.issn.1001-7461.2019.03.14
[36] 李峰卿, 王秀花, 楚秀丽, 等. 缓释肥N/P养分配比及加载量对3种珍贵树种大规格容器苗生长的影响[J]. 林业科学研究, 2017, 30(5): 743−750. Li F Q, Wang X H, Chu X L, et al. Effects of N/P ratio and loading on the growth of container seedling of three precious tree species[J]. Forest Research, 2017, 30(5): 743−750.
[37] 纪凯婷, 芦建国, 郭聪聪. 夏蜡梅1年生实生苗的生长节律[J]. 西北农林科技大学学报(自然科学版), 2015, 43(9): 165−170. Ji K T, Lu J G, Guo C C. Annual growth of one year old Sinocalycanthus chinensis seedling[J]. Journal of Northwest A&F University (Natural Science Edition), 2015, 43(9): 165−170.
[38] 韩立新, 汪有科, 张琳琳. 梨枣在果实生长期对土壤水势的响应[J]. 生态学报, 2012, 32(7): 2004−2011. doi: 10.5846/stxb201111181760 Han L X, Wang Y K, Zhang L L. Response of pear jujube trees on fruit development period to different soil water potential levels[J]. Acta Ecologica Sinica, 2012, 32(7): 2004−2011. doi: 10.5846/stxb201111181760
[39] 欧建德, 康永武. 容器规格对乳源木莲移植容器苗生长与生长节律的影响[J]. 西南林业大学学报(自然科学), 2020, 40(6): 1−7. Ou J D, Kang Y W. Effect of container size on growth rrocess and rhythm of Manglietia yuyuanensis containeried transplanting[J]. Journal of Southwest Forestry University (Natural Sciences), 2020, 40(6): 1−7.
[40] Egea G, Nortes P A, González M M, et al. Agronomic response and water productivity of almond trees under contrasted deficit irrigation regimes[J]. Agricultural Water Management, 2010, 97(1): 171−181. doi: 10.1016/j.agwat.2009.09.006
[41] Galvez D A, Landhausser S M, Tyree M T. Root carbon reserve dynamics in aspen seedlings: does simulated drought induce reserve limitation?[J]. Tree Physiology, 2011, 31(3): 250−257. doi: 10.1093/treephys/tpr012
[42] 刘亚清, 刘翠华, 宋景和. 兴安落叶松播种苗优化育苗模式研究[J]. 林业科技, 2010, 35(5): 18−21. doi: 10.3969/j.issn.1001-9499.2010.05.007 Liu Y Q, Liu C H, Song J H. Study on optimal seedling producing mode of Xingan larch seedlings[J]. Forestry Science & Tecnology, 2010, 35(5): 18−21. doi: 10.3969/j.issn.1001-9499.2010.05.007
[43] 娄玉穗, 王世平, 苗玉彬, 等. 不同灌溉阈值对‘巨峰’葡萄树体生长与果实品质的影响[J]. 果树学报, 2018, 35(1): 46−55. Lou Y S, Wang S P, Miao Y B, et al. Effect of different irrigation thresholds on tree growth and fruit quality in ‘Kyoho’ grape[J]. Journal of Fruit Science, 2018, 35(1): 46−55.
[44] 徐学欣, 王东. 微喷补灌对冬小麦旗叶衰老和光合特性及产量和水分利用效率的影响[J]. 中国农业科学, 2016, 49(14): 2675−2686. doi: 10.3864/j.issn.0578-1752.2016.14.003 Xu X X, Wang D. Effects of supplemental irrigation with micro-sprinkling hoses on flag leaves senescence and photosynthetic characteristics, grain yield and water use efficiency in winter wheat[J]. Scientia Agricultura Sinica, 2016, 49(14): 2675−2686. doi: 10.3864/j.issn.0578-1752.2016.14.003
[45] Liu H, Yu L P, Luo Y, et al. Responses of winter wheat (Triticum aestivum L.) evapotranspiration and yield to sprinkler irrigation regimes[J]. Agricultural Water Management, 2011, 98(4): 483−492. doi: 10.1016/j.agwat.2010.09.006
[46] Huang D F, Fang P, Li W H, et al. Effects of water and fertilizer managements on yield, nutrition uptake of rice and of nitrogen and phosphorus loss of runoff from paddy field[J]. Advanced Materials Research, 2012, 10(13): 1527−1532.
[47] Shock C C, Feibert E B G, Seddigh M, et al. Water requirements and growth of irrigated hybrid poplar in a semi-arid environment in eastern oregon[J]. Western Journal of Applied Forestry, 2002, 17(1): 46−53. doi: 10.1093/wjaf/17.1.46
[48] Xi B Y, Wang Y, Jia L M, et al. Characteristics of fine root system and water uptake in a triploid Populus tomentosa plantation in the North China Plain: implications for irrigation water management[J]. Agricultural Water Management, 2013, 117(3): 83−92.
[49] Landhäusser S M, Rodriguez A J, Marenholtz E H, et al. Effect of stock type characteristics and time of planting on field performance of aspen (Populus tremuloides Michx.) seedlings on boreal reclamation sites[J]. New Forests, 2012, 43(5−6): 679−693. doi: 10.1007/s11056-012-9346-4
[50] 黄国伟, 杨杉, 李振芳, 等. 不同水分梯度下楸树苗期生长及光合特征比较[J]. 生态科学, 2019, 38(1): 130−136. Huang G W, Yang S, Li Z F, et al. Comparative analysis of the growth and photosynthetic characteristics of the Catalpa bungei seedlings in different water gradients[J]. Ecological Science, 2019, 38(1): 130−136.
[51] Cuesta B, Villar S P, Puertolas J, et al. Why do large, nitrogen rich seedlings better resist stressful transplanting conditions? A physiological analysis in two functionally contrasting Mediterranean forest species[J]. Forest Ecology and Management, 2010, 260(1): 71−78. doi: 10.1016/j.foreco.2010.04.002
[52] 李国雷, 刘勇, 祝燕, 等. 国外苗木质量研究进展[J]. 世界林业研究, 2011, 24(2): 27−35. Li G L, Liu Y, Zhu Y, et al. A review of oversea studies of seedling quality[J]. World Forestry Research, 2011, 24(2): 27−35.
[53] 刘英, 曾琪瑶, 曾炳山, 等. 南洋楹无性系抗寒性研究[J]. 中南林业科技大学学报, 2020, 40(5): 7−12. Liu Y, Zeng Q Y, Zeng B S, et al. Physiological analysis on cold resistance of Albizia falcataria clones[J]. Journal of Central South University of Forestry & Technology, 2020, 40(5): 7−12.
[54] 李晓宇, 杨成超, 彭建东, 等. 杨树苗期抗寒性综合评价体系的构建[J]. 林业科学, 2014, 50(7): 44−51. Li X Y, Yang C C, Peng J D, et al. Evaluation system construction for cold resistance of poplar seedlings[J]. Scientia Silvae Science, 2014, 50(7): 44−51.
[55] Villar-Salvador P, Puértolas J, Cuesta B, et al. Increase in size and nitrogen concentration enhances seedling survival in mediterranean plantations: insights from an ecophysiological conceptual model of plant survival[J]. New Forests, 2012, 43(5−6): 755−770. doi: 10.1007/s11056-012-9328-6
-
期刊类型引用(8)
1. 赵海文,周长品,刘一贞,樊小丽,汤道平,李发根. 粗皮桉早期生长模型拟合以及生长节律研究. 华南农业大学学报. 2025(02): 212-221 . 百度学术
2. 吕坤,班以琛,坝仕宏,刘洋,文剑. 基于抚育整枝目标的毛白杨枝条冲击切割性能适应性分析. 北京林业大学学报. 2024(04): 158-166 . 本站查看
3. 欧建德,康永武. 不同坡位乳源木莲幼树的年生长动态和生长节律. 东北林业大学学报. 2024(09): 8-12+18 . 百度学术
4. 彭远航,冯嘉仪,龙凤玲,曾曙才. 三种园林植物幼苗生长节律对城市污泥的响应. 生态学杂志. 2024(10): 3055-3065 . 百度学术
5. 武海霞,李先耀,冀雅珍,郭爱科,任瑞瑞,康佳腾. 煤矸石粒径与矸土比对土壤理化特性及小白菜萌发的影响. 北方园艺. 2023(11): 1-8 . 百度学术
6. 王改萍,丁延朋,曹福亮,章雷,陈慧,赵群. 金叶银杏杂交F_1代苗木生长和叶色变化分析. 植物资源与环境学报. 2023(04): 1-11 . 百度学术
7. 丰伟,陈诗,单昌丹,张慧,姚增玉. 施肥对华山松容器苗根系形态及针叶生理特性的调控作用. 植物科学学报. 2023(04): 521-530 . 百度学术
8. 马惠英. 新时代背景下林业育苗与移植造林技术研究. 造纸装备及材料. 2022(09): 165-167 . 百度学术
其他类型引用(2)