黄河三角洲滨海湿地是我国暖温带地区最年轻、最广阔的湿地生态系统。由于其特殊的地理位置，已成为东北亚内陆和环西太平洋鸟类迁徙重要的“中转站”及越冬、栖息和繁殖地。近年来，由于受到环境变化和人类活动的干扰，黄河三角洲的芦苇湿地退化严重，鸟类栖息环境受到威胁。因此实施退化滨海湿地生态修复对于保护区域湿地生态环境及维持生态平衡具有重要意义。

本文通过实地调查和室内控制实验对黄河三角洲退化滨海芦苇湿地的恢复进行了研究。通过野外调查，掌握了黄河三角洲退化滨海芦苇湿地淡水恢复过程中植被生长、组成结构以及土壤理化性状的变化规律。通过室内不同的淡水补水期和补水深度控制实验，研究补水期和补水深度对植物生长、土壤理化性状的影响，探讨黄河三角洲湿地恢复过程中的适宜补水期和补水深度；研究不同水、盐梯度对芦苇种子萌发率和萌发速度的影响，探讨黄河三角洲湿地恢复过程中芦苇种子繁殖的可能性。研究结果表明：1）随着恢复时间的增加，芦苇群落的生态特征逐渐接近于自然芦苇湿地的生态特征，部分恢复湿地植物的生态特征甚至优于自然芦苇湿地。植物群落的植物种类先增加后减少，植物种类以禾本科和菊科为主，芦苇在各群落中始终占据着重要地位。随着湿地的恢复，植物从适宜较干旱少水或者是较高盐度的植物逐渐演变为适应湿水生环境或者低盐环境的物种。恢复湿地的物种丰富度和Shannon-Wiener多样性较之退化湿地有了明显改善，与自然湿地植物群落的相似性逐渐提高。2）黄河三角洲退化滨海芦苇湿地的人工淡水修复技术对土壤盐度的降低具有明显效果。随着淡水恢复时间的增加，恢复湿地的土壤含盐量逐渐降低，土壤pH值则逐渐升高，土壤有机质逐渐增加，有机质和土壤养分含量逐渐趋近于自然芦苇湿地的有机质和养分含量。3）芦苇根芽的成活率随着补水深度的增加逐渐降低，饱和水位（0 cm）对于芦苇根芽的萌发最为有利。在芦苇生长的中后期，10-15 cm水深对于调高芦苇的高度、生物量具有重要意义。植物高度、密度以及生物量等生态特征的峰指出现在10-15 cm，深度超过15cm，芦苇种群的生态特征逐渐降低。这说明10-15 cm水位最适宜芦苇种群的恢复。4）芦苇种子的萌芽率和萌芽速度随着盐度的升高而逐渐降低，芦苇种子在0.5%盐度具有最高的萌发率和萌发速度，而3%盐度时，芦苇种子的萌发速度和萌发率降至2%，芦苇种子在0 cm水深时萌发率最高，随着水深的增加，芦苇种子的萌发率逐渐降低，2 cm水深的芦苇种子萌发率和萌发速度也较高。低盐、浅水位有利于促进芦苇种子的萌发，而高盐、深水位则抑制芦苇种子的萌发。这说明利用种子繁殖技术加速黄河三角洲退化芦苇湿地的修复具有一定的可行性。

根据野外调查和室内试验结果，提出适宜黄河三角洲退化芦苇湿地修复的配套措施：利用现有的水利工程设施，在黄河三角洲地区的秋汛时节，存储淡水以供使用。每年的4月中上旬芦苇返青及萌芽时节，补入并保持0-10 cm深度的淡水，以刺激芦苇的返青和萌芽；6月下旬，芦苇植株已具有一定的承受能力，可以将补水深度提高到15 cm左右，同时，该地区也进入降水较多的时节，可以利用已有工程设施，将退化湿地中过多的水排出，保持恢复湿地水位在一定高度。在利用淡水恢复的同时，于每年的4月中下旬，选择良好天气在湿润区域进行芦苇种子撒播以加速湿地的恢复。本文的研究结果能够为充分利用黄河三角洲地区的淡水资源，加速退化湿地的恢复进程提供基础数据和科学依据，同时也可以为区域湿地的恢复提供模板，为其他地区相似湿地的恢复提供参考。

The Yellow River Delta (YRD) is the fastest growing delta and one of the most representative coastal wetland ecosystems in the world. The Yellow River Delta has become an important over-wintering and breeding site for migrating birds in Northeast Asian Inland and Western Pacific Rim. In recent years, suffering the impacts of interference of human activities and natural environmental changes, wetlands in the YRD have been deteriorated and lost considerably. Therefore, wetland restoration and reconstruction in the YRD play an important role in improving regional wetland ecological environment and maintaining ecological balance.

Varity of growth, composition structure of plant and changes of physical and chemical characteristics during process of wetland restoration in the YRD were studied by field research. Impacts of water irrigation time and water depth on plant and soil were studied by interior experiment to find the suitable irrigation time and depth to accelerate wetland restoration. At the same time, Laboratory experiments were carried out to assess the effects of salinity and water on seed of P. australis germination and to discuss the feasibility of sexual propagation. Results indicated: 1) Ecological characteristic of P. australis communities became similar to that of natural wetland, some one was even higher. Plant species increased first and then decreased, species belong to Gramineae and Compositae were dominate in community and P. australis was the most important in each community. Plant changed from species favored condition which was drought, less water and higher salinity to species favored condition which was aquatic or lower salinity. Compared with degraded wetland, species richness and Shannon-Wiener index of restored wetland increased first and then decreased: while natural P.australis wetland had the lowest ones. Similarity indexes between restored wetlands and natural wetland increased with the restoration time. 2) Inputting freshwater to degraded wetland can decrease soil salinity obviously in the YRD. Salinity of restored wetlands decreases gradually along restoration time and soil pH of restored wetlands increases. Soil organic matter of restored wetlands in the YRD increased with restoration time. Soil nutrient of restored wetlands was fluctuant without obvious rules, its content was decreased. As time increasing, content of SOM and other nutrient in restored wetlands get similar to that in natural wetland. 3) Survival rate of reed decreased with water depth increasing. At the early growth phase of reed, lower water depth is suitable for reed germination; it was the highest at 0cm water depth. At intermediate and final growth phase, 10cm to 15 cm water depth has great significant on increasing reed height and biomass. In this paper, ecological characteristic such as height, density, biomass got apex value at 10-15cm depth. This indicates that 10-15cm water depth was the suitable depth to recovery reed wetland. 4) Germination percentage and speed decreased with salinity increasing. Germination percentage and speed was the highest at 0.5% salinity treatment, while seed germination nearly inhibited completely at high salinity (3%) treatment. P. australis percent germination was decreased with water depth increasing except 2 cm water depth treatment. Lower salinity and water depth could stimulate germination of seed; however, higher salinity and water depth could inhibit seed germination. The results indicate that it is possible to accelerate the degraded coastal wetland restoration process of P. australis population by sexual ways in the YRD.

In this paper, support measures to restored degraded reed wetland were proposed according to results of field survey and laboratory experiments. Lay in fresh water in the season of autumn flood with existing Water Conservancy Facilities. In mid and late April, Supply fresh water to restored wetland and keep water depth at 0-10cm to stimulate reed germination and improve its survival. At late June, increase water depth to 15cm, because reed at this period grows strong enough to endure higher water depth. At the same time, there was too much rainfall to be discharged to keep water depth steady. Besides fresh water supplement to restore wetland, reed seed was also sown at moisture area and with good weather condition in mid and late April. This paper can provide basic data and scientific references to make good use of fresh water to accelerate wetland restoration in the YRD. It also can provide restoration experiences for the similar degraded wetlands.