Heritage trees have important historical, landscape, and ecological value. Exploring the spatial distribution pattern of heritage trees is of great importance to the construction of ecological civilization and the connotation of regional history and culture. This paper took 5,216 heritage trees in Luoyang, an ancient capital of China, as the research object and used geospatial analysis methods and a geographically weighted regression model to analyze the differences and driving forces of the spatial distribution of heritage trees. Results show that 1) the heritage trees in Luoyang were primarily Gleditsia sinensis, Sophora japonica, and Platycladus orientalis, and more than half of these trees were under 300 years old; 2) the high-density area formed a distribution pattern of “three cores, one ring, and two belts,” and the distribution of heritage trees had a positive spatial autocorrelation; 3) different driving factors in different regions had complex influences on the spatial distribution of heritage trees, and the order of influence was as follows: area of forest and orchard land > elevation > number of POIs (points of interest) > distance to the nearest river > slope > number of immovable relics. The results could provide a comprehensive understanding of the spatial distribution of heritage trees to protect the ecological function of heritage trees and mine the cultural value of heritage trees.
For animal-pollinated hermaphrodite plants, the factors that affect floral allocation were usually assigned to extrinsic (environment) and intrinsic ones (resources status). Few studies focused on the effect of rewarding type of plants (pollen vs. nectar and pollen). In this study, we investigated the variation in floral allocation per flower with respect to two distinct rewarding types for pollinators in 12 Pedicularis species in alpine regions, testing for the effects of species, plant size, and elevation simultaneously. The result showed that the rewarding type affected floral allocation significantly, and there was a female-biased floral allocation pattern in nectarless rewarding species relative to nectar and pollen rewarding ones and provided a new insight into variation in floral allocation. It was discussed with respect to activities and foraging behavior of pollinators on the basis of sex allocation theory. Moreover, environmental conditions (elevation) may also play a relatively important role in determining patterns of variation in floral allocation per flower, whereas plant size may not.
Light is a fundamental heterogeneous environmental factor for plants and often varies at both spatial and temporal scales. In the present study, we carried out a shading experiment to investigate the effect of variable light availability at the rosette stage of the first year in the strict biennial species Pedicularis torta (an endemic species of the QinghaiTibet Plateau) on reproductive traits (i.e. total number of flowers per plant, total number of fruits per plant/total number of flowers per plant, the number of seeds per fruit, mean individual seed mass and estimation of the total number of seeds per plant, plant size at maturity in the second year and on the relationships between reproductive traits and plant size at this stage). We found that light availability affected most of the reproductive traits (except for mean individual seed mass), plant size at maturity in the second year, and the relationship between the total number of flowers per plant and plant size at this stage. Our results indicate that reproductive traits respond to changes in light availability during the rosette plant stage.
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