Determining safe yield and mapping water level zoning in groundwater resources of the Neishabour Plain

Groundwater is a crucial sources of water supply,especially in arid and semi-arid areas around the world.With uncontrolled withdrawals and limited availability of these resources,it is essential to determine the safe yield of these valuable resources.The Hill method approach was used in this study to determine the safe yield the Neishabour aquifer in Khorasan Razvi province in Iran.The results showed that the safe yield in the Neishabour aquifer is 60%lower than the current pumping amounts during the study period,indicating that further overdrafts could result in the destruction of this aquifer.This highlights the importance of using the Hill method to estimate the permitted exploitation from other aquifers,thus preventing problems caused by over-extraction and maintaining stability of global groundwater levels.

Soil anti-scourability enhanced by herbaceous species roots in a reservoir water level fluctuation zone

Revegetation is one of the successful approaches to soil consolidation and streambank protection in reservoir water level fluctuation zones(WLFZs).However,little research has been conducted to explore the impact of herbaceous species roots on soil anti-scourability during different growth stages and under different degrees of inundation in this zone.This study sampled two typical grasslands(Hemarthria compressa grassland and Xanthium sibiricum grassland)at two elevations(172 and 165 m a.s.l.)in the water level fluctuation zone(WLFZ)in the Three Gorges Reservoir(TGR)of China to quantify the changes in soil and root properties and their effects on soil anti-scourability.A simulated scouring experiment was conducted to test the soil anti-scourability in April and August of 2018.The results showed that the discrepancy in inundation duration and predominant herbaceous species was associated with a difference in root biomass between the two grasslands.The root weight density(RWD)values in the topsoil(0-10 cm)ranged from 7.31 to 13 mg cm^(-3) for the Hemarthria compressa grassland,while smaller values ranging from 0.48 to 8.61 mg cm^(-3) were observed for the Xanthium sibiricum grassland.In addition,the root biomass of the two herbs was significantly greater at 172 m a.s.l.than that at 165 m a.s.l.in the early recovery growth period(April).Both herbs can effectively improve the soil properties;the organic matter contents of the grasslands were 128.06%to 191.99%higher than that in the bare land(CK),while the increase in the water-stable aggregate ranged from 8.21%to 18.56%.Similarly,the topsoil antiscourability indices in both the herbaceous grasslands were larger than those in the CK.The correlation coefficients between the root length density(RLD),root surface area density(RSAD)and root volume density(RVD)of fine roots and the soil antiscourability index were 0.501,0.776 and 0.936,respectively.Moreover,the change in the soil antiscourability index was more sensitive to alternations in the RLD with diameters less than 0.5 mm.Overall,the present study showed that the perennial herbaceous(H.compressa)has great potential as a countermeasure to reduce or mitigate the impact of erosion in the WLFZ of the Three Gorges Reservoir.

Fractal characterization of sediment particle-size distribution in the water-level fluctuation zone of the Three Gorges Reservoir, China

The combined effect of periodic water impoundment and seasonal natural flood events has created a 30 m high water-level fluctuation zone(WLFZ) around the Three Gorges Reservoir(TGR), China, forming a unique eco-landscape. Siltation, eutrophication, enrichment of heavy metals, and methane emissions in the WLFZ have been widely associated with sediment and soil particles generated from the upstream catchment or upland slopes. However, little attention has been paid to the complexity of sediment particle-size distributions in the WLFZ. In the present study, core samples(from a 345 cm thick sediment core from the base of the WLFZ), slope transect surface samples(across/up a WLFZ slope), and along-river/longitudinal surface samples(from the reservoir reaches) were collected. Laser granulometry and a volume-based fractal model were used to reveal the characteristics of sediment particle-size distributions. Results indicate that the alternation of coarse and fine particles in the sedimentary core profile is represented as a fluctuation of low and high values of fractal dimension(D), ranging from 2.59 to 2.77. On the WLFZ slope transect, surface sediment particles coarsen with increasing elevation, sand content increases from 3.3% to 78.5%, and D decreases from 2.76 to 2.53. Longitudinally, surface sediments demonstrate a downstream-fining trend, and D increases gradually downstream. D is significantly positively correlated with the fine particle content. We conclude that D is a useful measure for evaluating sediment particle-size distribution.

Protection and Ecological Restoration of Water Level Fluctuation Zone in the Three Gorges Reservoir

Water level fluctuation zone(hereinafter referred to as "WLFZ") is a transitional ecosystem between terrestrial ecosystem and aquatic ecosystem,and also a key area to control its neighboring terrestrial and aquatic ecosystem. After the Three Gorges Reservoir was put into use,ecological environment of its WLFZ has aroused wide concern from domestic and foreign experts. On the basis of introducing characteristics of WLFZ of the Three Gorges Reservoir,current ecological environment and main problems of this area were analyzed,plant selection and configuration was elaborated as well as the implementation effect of many WLFZ protection and ecological restoration modes. In view of the actual conditions,pertinent suggestions were proposed for WLFZ of the Three Gorges Reservoir,namely classified protection and ecological restoration,enhancing monitoring and assessment of current situation and change tendency,carrying out technical researches and demonstration of WLFZ wetland ecological restoration.

Influence of the Repeated Flooding on Growth and Development of Acorus calamus Vegetation in Water-level-fluctuation Zone of the Three Gorges Reservoir

[ Objective] The research aimed to study influence of the repeated flooding on growth and development of A. calamus in water-level-fluc- tuation zone of the Three Gorges Reservoir. [ Method] A. calamus plants were exposed to water under the dark conditions respectively in Septem- ber 2009 and September 2010. Then, they were taken away from the water, and grew in natural conditions in the following March and April respec- tively （ marked as S1, S2, S1 and S2）. The plant number was conducted statistics respectively. On May 7, the leaf number was made statistics. Length, width and rapid light responding curve of the leaf were determined. [ Result] Repeated flooding restrained significantly plant germination un- der the dark condition. Plant number in S1 and S2 groups decreased by 38.9% and 33.3% respectively compared with the control. It also reduced survival rate of the plant. Plant number in S2 group decreased by 16.7% （P 〈 0.05） compared with that of S2 group when they were taken away from the water. Both of flooding promoted elongation of the leaves, restrained leaves to grow wider, and also restrained leaf formation of the plants except for S1 and S1 groups. Total leaf length of a plant decreased markedly after the second flooding which in S1 and S2 groups were 50.6% and 36.9% respectively less than that after the first flooding. Total leaf number of the plant in S1and S2 groups reduced significantly, and they were only 63.1% and 38.5% respectively of the control. Compared with the first flooding, total leaf length of a plant in the control increased signifi- cantly and decreased remarkably in S2 group after the second flooding. Furthermore, light response ability of the relative electronic transfer rate （rETR） in S1 group wasn＇t significantly different from the control, and rETRmax, in S2 group was significantly less than the control. Moreover, non- photochemical quenching （NPQ） decreased remarkably in S1 and S2 groups. It indicated that A. calamus had good restore ability of the light re- sponse, but restoring of its heat dissipation capacity was slower. [ Conclusion] Repeated flooding inhibited plant growth and population recovery of A. calamus under the dark condition.

双酚A在消落带土壤中的吸附/解吸及降解行为

为探究双酚A(BPA)在消落带的环境行为,于涪陵清溪消落带采集不同高程土壤样品(S_(L):155m,S_(M):160m,S_(H):165m),开展批量吸附/解吸和模拟降解实验,研究了BPA在消落带土壤中的吸附、解吸及降解行为.15℃、25℃、35℃条件下,各高程土壤对BPA的吸附等温线符合Freundlich模型,吸附能力均随温度升高而降低,并表现出一定吸附非线性.各实验温度下,消落带土壤对BPA的吸附能力均与土壤有机质含量趋势一致,随采样高程降低而增加(S_(L)>S_(M)>S_(H)).吸附热力学参数ΔG、ΔH和ΔS均小于0,BPA在消落带土壤中的吸附为自发、放热的熵减过程,受物理吸附主导.解吸迟滞系数HI(0.853-0.981)接近1,BPA在消落带土壤中的解吸迟滞性不明显,易于解吸释放.25℃实验条件下,BPA在消落带土壤中的降解半衰期为S_(L)(4.88d)<S_(M)(6.68d)<S_(H)(10.07d),落干期较长区域的土壤中BPA降解速率更低.10℃条件下,BPA在土壤S_(H)中的降解半衰期延长至12.01d,分别为25℃的1.19倍和35℃的1.20倍,低温条件抑制BPA的降解.

周期性水位波动对三峡水库消落带土壤有机碳含量和密度的影响

为探究水位波动对三峡水库消落带土壤有机碳的影响,在三峡水库消落带采集和测定了受不同水淹强度影响的石灰土、紫色土、黄壤及其植物样品,并运用Kruskal-Wallis非参数检验和基于冗余分析的典范分析等方法进行了研究。结果表明:周期性水淹增加了石灰土和紫色土的有机碳含量和密度,但降低了黄壤的有机碳含量和密度。此外,石灰土的有机碳分布还受地上生物量、土壤pH和土层深度的影响,紫色土的有机碳分布还受土层深度和地上生物量的影响,而黄壤的有机碳含量和密度则与地上生物量、土层深度和地下生物量有关。总之,周期性水位波动对消落带土壤有机碳影响深刻,但土壤类型分异了有机碳对水位波动的响应。

南四湖消落带底泥中磷及微生物群落结构研究

研究不同频率干湿交替条件下,南四湖消落带底泥磷形态变化及其与生物群落结构的关联性,可为维持南四湖消落带水生态系统健康及保障南四湖水质提供技术支持。文章模拟了南四湖消落带底泥不同频率干湿交替过程,通过高通量测序技术分析了底泥生物群落的变化特征。结果表明:在干湿交替过程中,底泥总磷、无机磷呈降低趋势,而有机磷基本保持不变;不同干湿交替过程中消落带底泥微生物群落结构比较稳定,但群落丰度变化显著;频繁干湿交替不利于消落带底泥保持微生物多样性;消落带底泥中蓝藻门(Cyanobacteria)和疣微菌门(Verrucomicrobiota)与底泥中NaOH-P呈显著负相关,变形菌门(Proteobacteria)与总磷则呈正相关。

南昌市象湖湿地公园消落带植物景观生态修复策略

为减轻城市湿地公园的消落带生态退化问题(环境污染、水土流失、土壤侵蚀、功能退化等),探求高效的生态修复策略。以南昌市象湖湿地公园为研究对象,在系统分析消落带的共性生态环境问题及现状基础上,提出了相应的景观生态修复策略:1)在广泛调查地域性消落带植物种类及其群落组成的基础上,筛选出适合公园环境的湿生植物种类;2)适度调整消落带的护坡和护岸结构,以自然式护岸为主;3)以乡土的湿生植物为主,建议配植适生植物群落,修复受损的消落带生境,形成特色护岸景观。研究城市湿地公园消落带的植物景观生态修复,有利于实现消落带生境修复、景观游憩、水体净化、减污增汇等生态效益,以构建生态环境友好型的消落带景观。

三峡水库消落带生境特征与植被恢复模式

[目的]三峡水库蓄水运行后消落带生境破碎斑块化加剧,极端生境胁迫严重损害植被的结构和功能。厘清三峡水库消落带生境状况,提出适宜性植被恢复对策,重建河流受损廊道综合生态功能,对构建区域生态安全格局和保障长江流域水资源安全具有重要意义。[方法]针对三峡水库消落带植被退化与生态功能受损的突出问题,系统解析了消落带生境特征及其对植被生长的影响,围绕水库河岸受损廊道生态修复重大需求,探讨面向消落带微生境构建与植被格局功能优化的三峡水库消落带植被恢复模式。[结果]三峡水库消落带生境状况受水库运行形成的独特水位节律、出露期植被生长季气候条件、土壤侵蚀与泥沙沉积过程、土壤环境等多生境因子协同影响,呈现高度空间异质性特征。水位变动形成的淹没时长、出露时令、淹水强度是影响植株繁衍、生长的首要因素;土壤侵蚀、泥沙掩埋、土壤水养条件等影响植被生长状况。[结论]三峡水库消落带植被恢复需综合考虑水位节律、立地条件与物种形态-功能性状,选育优质抗逆物种,注重土壤基质保育,突出植被格局的分区优化配置。重建消落带综合生态功能,为水库消落带生态治理提供理论支撑和科学依据。

农业耕作和外来植物入侵对金沙江下游库区新生消落带土壤养分和酶活性的影响

金沙江下游梯级水电站新生消落带上农业耕作较为普遍,同时广泛存在外来植物入侵,这可能会对其土壤养分状况产生潜在影响。基于此,以乌东德电站库区新生消落带为研究区域,以淹水后自然形成的狗牙根(Cynodon dactylon)群落为对照,选择典型农作物玉米(Zea mays)与入侵植物银胶菊(Parthenium hysterophorus)为研究对象,通过比较不同群落下0~10 cm和10~20 cm深度土壤养分含量及酶活性差异,探讨农业耕作和外来植物入侵对消落带土壤养分状况的影响。结果表明:①玉米和银胶菊群落下0~10 cm土层有机质、全氮、全磷、速效钾含量显著高于狗牙根群落(P<0.05),增幅为24.58%~136.98%;10~20 cm土层的有机质、氮磷钾养分全量和速效养分含量也较狗牙根群落显著高出16.67%~141.68%(P<0.05)。②相较狗牙根群落,玉米和银胶菊群落下0~10 cm和10~20 cm土层的脲酶、蔗糖酶、碱性磷酸酶、硝酸还原酶活性均显著增加(P<0.05),增幅为5.60%~378.65%。3个群落中,银胶菊群落土壤酶指数最高,较狗牙根群落显著高出23.49%(P<0.05)。③消落带土壤有机质、全氮、全磷、碱解氮、有效磷、速效钾含量均与脲酶、蔗糖酶、硝酸还原酶、碱性磷酸酶活性之间呈显著正相关(P<0.05),表明上述酶活性可作为消落带土壤养分状况变化的有效表征。总的来看,农耕活动和银胶菊入侵促进了落干期金沙江下游新生消落带土壤养分的积累和有效性的增加。因此,应加强消落带农业耕作的管控并尽快开展入侵植物防治,以减少淹水期消落带土壤养分流失风险。

三峡水库消落带土壤反硝化及DOM的影响

在重庆主城与涪陵选取了3个典型点位采集土壤样品,并对土壤的理化性质、原位反硝化速率、溶解性有机质(DOM)驱动的反硝化以及库区土壤的微生物进行了考察与分析.结果显示在海拔145~155m区间,淹水期镇安镇、涪陵区和鱼嘴镇最高氨氮(NH_(4)^(+)-N)平均浓度分别为31.32,28.63和19.23mg/kg,均高于落干期.在淹水期,与高海拔区域土壤中硝酸盐氮(NO_(3)^(-)-N)平均浓度相比,低海拔土壤中NO_(3)^(-)-N平均浓度分别增大了46.91%(镇安镇)、37.89%(涪陵区)和29.69%(鱼嘴镇).在淹水期,土壤有机质(SOM)平均浓度随着海拔高程的降低而降低,镇安镇、涪陵区和鱼嘴镇分别从109.16,80.93和82.61mg/kg降至65.63,64.53,53.41mg/kg.土壤中NH_(4)^(+)-N和NO_(3)^(-)-N的含量与现场反硝化速率呈显著正相关(P<0.05),在提供充足的碳(C)和氮(N)营养元素后,土壤潜在反硝化速率表现出较大的时间和空间差异性.在由DOM驱动的反硝化实验中,DOM降解符合一级动力学模型(R^(2)>0.93),N2O累积量符合Logistic模型(R^(2)>0.97).在三峡水库消落带土壤中,反硝化功能微生物主要是Bacillus和Comamonadaceae,其丰度变化与土壤潜在反硝化速率呈现显著的正相关性(P<0.05).

消落区沉积物落干期氮磷形态分析——以碧流河水库为例

水库水位变动致使消落区沉积物经历着频繁的干湿交替,为探讨落干过程对沉积物氮、磷的影响,以碧流河水库为例采集了消落区不同高程下的沉积物样品,并基于现场条件设计落干模拟试验,探讨持续落干条件下消落区沉积物氮、磷的多形态变化特征,为水库内源污染治理提供参考。研究发现:在沉积物干化过程中,受反硝化作用的影响,落干期TN的含量减少了2.99%,但随着水分蒸发反硝化作用易于发生的条件被破坏,TN的含量逐渐稳定;受矿化作用的影响存在有机磷(OP)向无机磷(IP)的形态转化,该转化提高了磷的生物有效性,且干化过程中会出现氮、磷向表层富集的现象。因此,持续的落干作用有利于沉积物中过量氮素的去除,有助于消落区植物生长和初级生产力的提升。

多开发主体梯级电站实时负荷控制模型研究

由于多开发主体下梯级水电站间不能共享实时负荷数据,上一级电站发电负荷变动常导致本级电站非正常弃水或低水位运行问题。为解决这个问题,提出了基于预测控制的多开发主体梯级电站实时负荷控制模型来控制水位。模型分为实时跟踪、预测控制和厂内负荷分配3部分。实时跟踪每1 h进行一次入库流量反推计算来推算预测入库流量序列;预测控制根据标准差选择不同流量递推模型推算入库流量;厂内负荷分配以耗水量最小进行负荷分配优化,实现上游电站负荷及发电流量未知情况下的梯级电站实时负荷分配并保持水位稳定。所提出的实时负荷控制模型应用于木里河梯级电站实时负荷分配,对多开发主体下流域梯级水电站实时负荷分配,维持水位稳定具有一定的指导意义。

黑龙滩水库消落带植被恢复模式对土壤水稳性团聚体组成及其稳定性的影响

[目的]为阐明水库消落带不同植被恢复模式对土壤水稳性团聚体组成及其稳定性的影响。[方法]以川中丘陵区黑龙滩水库消落带人工恢复与自然恢复植被下的土壤为研究对象,利用湿筛法测定分析土壤水稳性团聚体组成特征及其稳定性指标。[结果]消落带土壤>0.25 mm水稳性大团聚体含量与未淹水对照相比降低4.21%,其中,自然恢复植被下土壤水稳性大团聚体含量较对照下降12.27%,人工恢复植被下大团聚体含量较对照增加3.84%;不同植被恢复模式下土壤水稳性团聚体组成差异显著(p<0.05),人工恢复植被下土壤大团聚体含量(69.48%)显著高于自然恢复模式(43.20%);消落带土壤水稳性团聚体稳定性随水位高程增加而升高,团聚体稳定性指标>0.25 mm水稳性团聚体含量(R_(0.25))、平均重量直径(MWD)、几何平均直径(GMD)人工恢复模式下均大于自然恢复模式,团聚体分形维数(D)、土壤可蚀性因子(K)与团聚体破坏率(PAD)人工恢复模式小于自然恢复模式,表明人工恢复模式下土壤水稳性团聚体稳定性、土壤抗蚀性高于自然恢复模式。[结论]黑龙滩水库消落带在淹水后土壤团聚体稳定性下降,但人工恢复模式能有效改善土壤团粒结构,研究结果可为黑龙滩水库消落带土壤结构稳定性评价及植被恢复提供科学依据。

水位变动区硫酸根侵蚀对混凝土氯离子传输影响试验研究

海洋环境水位变动区是氯离子和硫酸根离子侵蚀最严重的区域,氯离子主要破坏钢筋钝化膜引起钢筋锈蚀,硫酸根离子侵蚀除导致混凝土物理力学性能劣化外,还对氯离子在混凝土中的传输产生影响。目前针对硫酸根离子对氯离子传输影响的研究主要采用将试件浸泡在侵蚀溶液中的方式,不能反应耐久性问题更为严重的海洋水位变动区混凝土内离子传输规律。文章采用自主研制的潮汐循环模拟系统,开展了海洋环境水位变动区单一氯离子和氯离子-硫酸根离子耦合环境下氯离子传输特性物理试验,研究了硫酸根离子侵蚀对混凝土中氯离子传输规律的影响,给出了混凝土表面氯离子浓度和表观氯离子扩散系数的时变公式,建立了海洋环境水位变动区考虑硫酸根离子侵蚀效应的氯离子扩散模型。结果表明,早期由于硫酸根离子侵蚀在混凝土中生成石膏和钙矾石的填充作用,阻碍了氯离子在混凝土中的传输,使混凝土中氯离子浓度降低。

三峡库区消落带植物群落及其功能性状对水淹强度的响应

植物功能性状能表征其对资源的利用能力和对外界环境的响应,而水淹强度的不同使得三峡库区消落带不同高程的生境存在较大差异,因此开展不同水淹梯度下消落带植物群落生态策略及功能性状差异的研究,对全面理解植物对消落带不同生境的适应机理具有重要意义。研究选取受三峡水库水位变化影响的澎溪河流域,沿高程梯度对不同水淹强度下的植物群落及其功能性状指标进行分析。结果表明:(1)消落带植物群落处于演替的初级阶段,不同水淹梯度下的植物群落存在显著分化;(2)环境胁迫是决定消落带植物生态策略的主要因素,总体呈现较为集中的耐压策略,随着高程升高有逐渐向杂草策略转移的趋势;(3)随着高程升高,植物的高度、主茎干物质量、比根长及叶组织密度都有增大的趋势,比叶面积则相反。(4)各功能性状之间存在显著相关性,并通过形成不同的性状组合以适应不同强度水淹干扰的生境。消落带下部更倾向于投资于叶片使植物在出露期能快速获取资源和完成生活史,而消落带上部则更倾向于投资防御组织及根系以抵御干旱,研究结果可为消落带生物多样性保护及其生态系统修复提供理论依据。

濒危物种疏花水柏枝残存种群有性繁殖的时空变化

本文以分布于枝江关洲岛的濒危物种疏花水柏枝(Myricaria laxiflora(Franch.)P.Y.Zhang et Y.J.Zhang)为研究对象,调查其种群开花和结果性状沿高程的变化,分析该残存种群有性繁殖的时空变化规律;同时结合三峡大坝-葛洲坝水利水电工程修建所引起生境地水位消涨节律的变化,分析其对残存种群有性繁殖的影响。结果显示,残存疏花水柏枝种群的有性繁殖在不同高程之间存在显著差异。消涨带上部植株的每株花枝数、每枝花朵数、每株花朵数分别比消涨带中部植株高66.09%、50.14%和98.63%,比消涨带下部植株高79.50%、283.33%和461.05%。消涨带上部植株的每株果枝数、每枝结果数、每株结果数、每果种子数和种子发芽率分别比消涨带中部高60.17%、25.26%、88.05%、6.96%和30.69%,比消涨带下部高97.39%、82.45%、208.31%、19.12%和45.91%。相关性分析结果表明,植株的开花结果特性与高程、出露时期、土壤含水量以及温度变化极显著相关。环境因子对有性繁殖的影响强度依次为出露时间>高程>日均温度>土壤含水量。上游水利水电工程对疏花水柏枝残存种群的有性繁殖具有一定的影响。

三峡水库消落带狗牙根根系对紫色土抗剪性能的影响

植物根系对提高土壤抗侵蚀能力起着最主要的作用。为探究根系对三峡水库消落带土壤抗剪性能的影响,以典型草本植物狗牙根及其根土复合体为研究对象,利用原状土和重塑土、采用直剪试验和三轴试验2种方法,揭示根系形态特征、含根量以及布根方式对土壤抗剪性能的影响。结果表明:1)内摩擦角、黏聚力与根系形态特征呈对数正相关;各形态指标对土壤抗剪性能的影响程度依次为:根表面积密度>根体积密度>根长密度>根质量密度>根径。2)根系含量与土壤抗剪性能呈正相关。含根量分别为0.9、0.6和0.3 mg/cm^(3)的根土复合体抗剪强度依次比素土提高14.54%~49.56%、9.09%~35.82%和3.80%~17.58%;内摩擦角依次提高13.95%、13.07%和1.98%;黏聚力依次提高29.37%、24.48%和15.34%。3)交叉布根下土壤抗剪性能最强,与垂直布根、水平布根相比,交叉布根的抗剪强度依次提高4.22%~16.95%和11.45%~32.61%;黏聚力依次提高15.61%和16.09%;最大应力值依次提高3.78%~34.18%和36.86%~41.44%。研究结果可为三峡水库消落带固土护岸的物种筛选、水土保持生态建设以及水库岸线管理等提供参考。

金沙江观音岩水库消落带绝对优势植物的表型可塑性与适应策略

金沙江是长江上游梯级大库富集之地,在金沙江地区选择典型水库开展植物表型可塑性和适应策略研究对该区一众水库生态治理具有重要的参考价值。本文以金沙江观音岩水库消落带为研究区,定量比较了经多年周期性水淹干扰后,绝对优势植物根茎叶性状的表型可塑性,分析了绝对优势植物应对主导因子的关键性状及其协同响应特征和权衡策略。结果表明:1)调查共记录了植物种类11科21属21种,优势度大于0.1的仅有狗牙根和苍耳,为绝对优势种。2)淹水对狗牙根和苍耳功能性状具有极显著影响,是二者功能性状变异的主导因子。3)狗牙根的株高、主茎长、分茎数量、主茎宽、叶片数量和叶面积,以及苍耳的分茎数量、叶片数量、根冠比和比叶面积的表型可塑性指数均超过0.6,是应对淹水的敏感性状。但是,狗牙根的叶片数量、叶面积以及苍耳的比叶面积对淹水的可塑性响应表现出短期时效性,为非适应性可塑性。4)淹水深度调控狗牙根在“逃避”策略和“静默”策略之间的权衡选择,并通过不同的性状组合以及地上和地下部分资源分配以协同响应。5)淹水导致狗牙根和苍耳的生态对策趋同,均采取S/SR策略。此外,相比于狗牙根为水库消落带的普遍推荐种,苍耳因其存在水质污染风险而褒贬不一,但苍耳具有重要的药用价值,能否在每次淹水来临前进行刈割值得进一步探讨。