In the present study,the biological characteristics of seed germination were investigated for five typical populations of Juniperus rigida growing in different regions of the Loess Plateau,and their relation with climatic and soil factors were studied. The results showed significant difference in seed size among the five regions,with Wuchuan being the smallest with respect to seed length(6. 83 mm),width(3. 56 mm),and seed weight(25. 89g). Seed length and ratio of length/width decreased as latitude and soil ...