Abstract. Rangelands of China have for centuries provided forage for livestock but now their role in water, soil, and biodiversity conservation is being recognised by Governments and people. However, much of the rangelands has recently degraded and desertification is now a widespread problem. The cause of the degradation is over-grazing and over-cultivation. Climate change is exacerbating the problem. The Chinese Governments have begun to address these severe problems through policy adjustments and projects. In parallel, some research and development is taking place. There are major impediments to addressing the problem; the importance of rangelands to China and its people are generally underestimated, legislative protection is incomplete and often ineffective, little attention is paid to scientific knowledge for development of management of natural resources, there is insufficient technological support, and Governments are not able to invest sufficiently to effectively restore and develop rangeland natural resources. However, with this background we propose how the problems might be more effectively addressed in the future.

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Although many studies have been done on seeds with physical dormancy, i.e. water-impermeable seed or fruit coat, the primary site of water entry into seeds after dormancy-breaking treatments is still controversial. In this work, the role of the lens in physical dormancy breaking was examined. The present study investigated the primary site of water entry and changes in seed-surface features for seeds of Sophora alopecuroides L. following various periods of scarification with sulfuric acid, hot-water treatments, and exposure to field conditions. Most seed coats first cracked in the hilum when pre-treated with sulfuric acid and after field exposure, but they cracked in both the hilum and extrahilar regions when treated with hot water. After pre-treatment, seeds first became slowly permeable in the hilum or extrahilar region and not in the lens. Acid scarification for 35 or 50 min caused the lens to crack, thus causing seeds to enter a fast imbibition stage. Seeds exposed to field conditions had further damage to the hilum, causing them to enter a fast imbibition stage. Imbibition time is a key point that determines the primary site of water entry into seed, and at least in part explains various results and interpretations about the role of the lens in physical dormancy in previous research.

mance. The critical requirements of a vigor test include (i) it must provide a more sensitive index of seed quality Laboratory and field tests were conducted in 1999 and 2000 in than does SG (McDonald, 1980;Perry, 1984) and (ii) it Gansu Province, China, to investigate the suitability of various laboratory vigor tests, to rank quality of commercial seed lots, and to predict must better predict planting value of high germinating seedling field emergence (FE) of four forage species. Species used seed lots than does SG (Hampton and TeKrony, 1995). included two legumes, purple vetch (Vicia benghalensis L.) and alfalfa Although some vigor test methods have been developed (Medicago sativa L.), and two grasses, sudangrass [Sorghum bicolor and successfully used for several major agronomic crops (L.) Moench subsp. drummondii (Steud.) de Wet ex Davidse] and (AOSA, 1983; Hampton and TeKrony, 1995), these Siberian wild ryegrass (Elymus sibiricus L.). Results showed that methods have not been studied extensively in forage among all tests, the electrical conductivity (EC) test provided the best crops (Wang et al., 2001).estimate of seed vigor for the two legume species, both for ranking Hampton (1989, 1991) reported that CD seed lots quality and predicting FE, but gave the worst indication of and EC tests were more sensitive and accurate for prediseed lot vigor for the two grass species. The EC result was not only cating red clover (Trifolium pratense L.) storability and 2002. *Corresponding author (yrwang66@public.lz.gs.cn).