青海省东部地区几种野生和引进树种育苗及造林技术研究 英文标题:The Study on Breeding and Afforestation of Several Wild and Introduction Species at the Eastern Part of Qinghai Province

青海省地处青藏高原的东北部，与黄土高原交汇，是长江、黄河、澜沧江的发源地，土地总面积72.12万km~2。该区生态环境的显著特点是干旱少雨、气候寒冷、植被覆盖率低、水土流失严重、生态脆弱、自然灾害频繁。其中海拔1650m～3000m、年降雨量200mm～400mm的浅山是本区水土流失最严重的地区，是青海省荒山造林、退耕还林(草)和治理水土流失的重点地区。该地区造林树种单一，可供选择的适宜树种及其综合配套技术比较缺乏。青藏高原独特的自然条件孕育了许多抗逆性强、经济价值高的野生树种，这些树种更能适合青海东部的立地和气候条件，因此，充分利用当地丰富的野生植物资源，筛选适宜的树种进行驯化栽培，同时根据地域、生态相似性原理引进外来优良树种，开展相关配套技术研究，对加快青海省东部旱区造林步伐，减少水土流失，改善生态环境具有重大的现实意义。论文通过对参试树种育苗、造林等方面的试验研究，得出以下结论:1、在前期研究成果的基础上，通过种子处理、育苗基质、覆土深度、播种季节及管理等育苗技术对霸王、唐古特白刺、沙木蓼、匙叶小蘖、洛基山刺柏、银水牛果等树种进行繁育研究，使霸王容器播种育苗出苗率提高6.9%，唐古特白刺播种出苗率达到91%，匙叶小檗播种出苗率提高18%，生长量提高37%。对沙木蓼、洛基山刺柏等一些有发展前景的引进树种或不易于种子繁殖的树种，采用无性繁殖的方法，采用基质配比、激素处理等技术进行试验研究，使沙木蓼高生长量提高135.9%，洛基山刺柏平均总生根率达到97.4%，银水牛果扦插成活率提高87.8%。极大地缩短育苗周期，并形成较为成熟的育苗技术方案。2、根据青海东部地区造林立地类型及所筛选树种的不同特性，利用容器苗造林技术、营养袋法造林技术、雁翅形集流整地技术以及生长剂和保水剂使用技术，进行干旱浅山造林试验，能有效增加造林成活率。利用雁翅形集流整地方式使土壤含水量提高35.5%，使用50ppmGGR泥浆沾根造林，霸王和唐古特白刺造林成活率分别提高28.7%和33%，用1.5‰吸水剂(根宝)浸根后造林，成活率分别提高27.7%和28%，用营养袋法造林成活率提高0.5～22.2%。3、通过树种引育和区域造林试验，选育出的霸王、沙木蓼、唐古特白刺、银水牛果、匙叶小蘖、鲜黄小蘖、洛基山刺柏、甘蒙锦鸡儿、高山绣线菊、北方枸杞、小果白刺、白柠条、树锦鸡儿等树种可基本满足湟水流域低海拔地区极端立地条件和黄河流域大部分地区干旱荒坡造林。其中霸王、小果白刺、唐古特自刺、北方枸杞具有很强的耐盐碱能力。西宁北山重盐碱化干旱阳坡土壤盐渍化严重，pH值8.0～9.02，全盐量5.21%，以上树种进行配置试验，保存率达到73%以上，实现了极端立地条件下造林技术的突破。

Qinghai Province is situated in the northeastern section of the Qinghai-Tibet Plateau, where it borders the Loess Plateau. It serves as the source region of the Yangtze River, Yellow River and Lancang River, with a total land area of 721,200 km². The prominent ecological features of this region include scarce rainfall and drought, frigid climate, low vegetation coverage, severe soil erosion, fragile ecosystem and frequent natural disasters. The low mountainous areas with an altitude of 1650–3000 m and annual precipitation of 200–400 mm suffer the most severe soil erosion here, and are the key zones for barren hill afforestation, conversion of cropland to forest and grassland, and soil erosion control in Qinghai Province.

The local afforestation is limited by single-species planting and a shortage of suitable tree species and their supporting comprehensive technical systems. The unique natural conditions of the Qinghai-Tibet Plateau have bred numerous wild tree species with strong stress resistance and high economic value, which are better adapted to the site and climatic conditions of eastern Qinghai. Therefore, making full use of local abundant wild plant resources, screening suitable tree species for domestication and cultivation, introducing excellent exotic tree species based on the principle of geographical and ecological similarity, and conducting relevant supporting technical research are of great practical significance for accelerating afforestation progress in the arid regions of eastern Qinghai, reducing soil erosion and improving the ecological environment.

Based on experimental studies on seedling cultivation and afforestation of tested tree species, this paper draws the following conclusions:
1. On the basis of preliminary research findings, breeding experiments were carried out on *Zygophyllum xanthoxylon* (Bawang), *Nitraria tangutorum* Bobr. (Tangut Nitraria), *Atraphaxis bracteata* A. Los. (Sha Mu Liao), *Berberis virgetorum* C. K. Schneid. (Chiye Xiaobo), *Juniperus scopulorum* Sarg. (Rocky Mountain Juniper) and *Shepherdia argentea* Nutt. (Silver Buffaloberry) via seed treatment, seedling substrate optimization, soil covering depth adjustment, sowing season selection and field management. These measures increased the container sowing seedling emergence rate of *Zygophyllum xanthoxylon* by 6.9%, raised the sowing seedling emergence rate of *Nitraria tangutorum* to 91%, improved the sowing seedling emergence rate of *Berberis virgetorum* by 18% and increased its growth by 37%. For promising introduced tree species or those difficult to propagate via seeds such as *Atraphaxis bracteata* and *Juniperus scopulorum*, asexual propagation experiments were conducted using substrate ratio adjustment and hormone treatment. These trials increased the height growth of *Atraphaxis bracteata* by 135.9%, brought the average total rooting rate of *Juniperus scopulorum* to 97.4%, and improved the cutting survival rate of *Shepherdia argentea* by 87.8%, greatly shortening the seedling cultivation cycle and forming a relatively mature technical scheme for seedling raising.
2. Based on the afforestation site types in eastern Qinghai and the distinct characteristics of the screened tree species, afforestation experiments were conducted in arid low mountains using container seedling afforestation, nutrient bag afforestation, wing-shaped runoff-collecting land preparation, and application technologies of growth regulators and water-retaining agents, which effectively improved afforestation survival rate. The wing-shaped runoff-collecting land preparation increased soil moisture content by 35.5%. When applying 50 ppm GGR mud root-dipping for afforestation, the survival rates of *Zygophyllum xanthoxylon* and *Nitraria tangutorum* increased by 28.7% and 33% respectively. After soaking roots with 1.5‰ water-retaining agent (Genbao) before afforestation, their survival rates rose by 27.7% and 28% respectively, and the nutrient bag afforestation method improved survival rate by 0.5–22.2%.
3. Through tree species introduction, breeding and regional afforestation trials, the selected tree species including *Zygophyllum xanthoxylon*, *Atraphaxis bracteata*, *Nitraria tangutorum*, *Shepherdia argentea*, *Berberis virgetorum*, *Berberis viridiflora* C. K. Schneid., *Juniperus scopulorum*, *Caragana davazamcii* Sancz., *Spiraea alpina* Pall., *Lycium chinense* Mill., *Nitraria sibirica* Pall., *Caragana korshinskii* Kom. and *Caragana arborescens* Lam. can basically meet the afforestation requirements for extreme site conditions in low-altitude areas of the Huangshui River Basin and arid barren slopes in most regions of the Yellow River Basin. Among these species, *Zygophyllum xanthoxylon*, *Nitraria sibirica*, *Nitraria tangutorum* and *Lycium chinense* exhibit strong salt and alkali tolerance. The highly salinized arid sunny slope in the North Mountain of Xining has severe soil salinization, with a pH value of 8.0–9.02 and total salt content of 5.21%. When the above tree species were used for configuration experiments, the survival rate reached over 73%, achieving a breakthrough in afforestation technology under extreme site conditions.