关键词: 囊果草, 生物学特性, 种子传播, 点格局分析, 生态适应

Abstract: This study aimed to document the ecological adaptability of biological traits and the population distribution pattern of the ephemeral desert plant Leontice incerta in the northern Xinjiang region. Data gathered included biological characteristics, seed production traits, dispersal mechanisms and population distribution patterns in the natural habitat. L. incerta has membranous fruits that form bladders around the seeds and are dispersed by wind rolling, and a swollen irregular underground tuber. Flowers of L. incerta temporarily close in response to cool overnight temperatures in their desert environment. The number of fruits per plant was, on average, 8.29. Fruit have reticulate venation at the sides and base, with the bottom veins thicker and not easy broken, and the apex of the fruit is without veins and thin and paper-like with blue-purple spots. This fruit apex is easily punctured when the fruit matures. Each fruit on average had 2.82 spherical seeds. Long-distance dispersal is achieved through release of seeds from the fruits as they roll in the wind. Average plant height was 18.9 cm, and average tuber diameter was 3.5 cm, but tuber size increased with plant age. To understand seed dispersal characteristics in this species, laboratory simulation studies of capsule movement with variables capsule size, air speed, and surface roughness were carried out, and plant and seedling distribution in the field was studied and analyzed. In the laboratory study, the distance travelled by capsules increased with increasing capsule size and decreased with increasing surface roughness. Seeds were released as capsules travelled, so that total seeds dispersed per capsule increased with distance, while seeds dispersed per unit area of ground decreased with increasing distance. Increased surface roughness increased capsule puncture and seed release from capsules. In the field, correlation between position of adult plants and position of seedlings increased up to 18 m distance from the adult plant and decreased at greater distances, while plant distribution was uniform on a 0-2 m scale, aggregated on a 2.5-14.0 m scale, and random on sampling scales greater than 14 m.

Key words: Leontice incerta, biological characteristics, seed dispersal, point pattern analysis, ecological adaptability