封面植物——思茅松

思茅松(Pinus kesiya var.langbianensis)是松科(Pinaceae)松属(Pinus)卡西亚松(Pinus kesiya Royle ex Gordon)的地理变种,常绿大乔木,高达30 m,直径可达1 m,每年生长两轮或多轮枝条,一年生枝条呈淡褐色或淡褐黄色。其针叶呈束状,每束3针,长10~22 cm。球果卵圆形.

多伦县沙地樟子松人工林天然更新苗生长特征

樟子松(Pinus sylvestris var.mongolica),又称海拉尔松,是欧洲赤松(Pinus sylvestris)的地理变种,具有抗寒、抗旱和较速生等优良特性,是我国北方半干旱风沙地区主要造林树种。在原产地呼伦贝尔沙地年平均降水量380毫米的自然条件下,樟子松能够顺利完成天然更新过程。而在多数引种地,樟子松天然更新困难,有些地区即使能天然更新,但更新强度和频率也较低。

Variation, heredity and selection of effective ingredients in Magnolis officinalis of different provenances

Bark samples of Magnolis officinalis were collected from a 7-year-old trial plantation with 13 provenances in Jingning County of Zhejiang Province on June 25, 2000. The contents of magnolol and honokiol of M. officinalis were analyzed by the method of HPLC (High Performance Liquid Chromatogram). The results showed that such qualitative traits as the content of magnolol, content of honokiol, total content of key phenols, and the ratio of magnolo to honokiol differ significantly between the provenances. The provenances with a sharpened leaf tip from the western part of Hubei Province has a highest content of phenols, and that with a concave leaf tip from the Lushan Mountain has a lowest content of phenols. All these four qualitative traits were genetically controlled, with a heritability between 0.8342 and 0.9871 in terms of provenance. In addition, both longitudinal and latitudinal geographical variations could be found, with longitudinal variations being dominant. As a result, 3 superior provenances from Wufeng, Enshi and Hefeng of the western part of Hubei as well as 10 high-quality individuals were selected.

Genetic variations of wood properties and growth characters of Ko-rean pines from different provenances

Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously dif-ference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude.

Interspecific Transition Among Caragana microphylla, C. davazamcii and C. korshinskii Along Geographic Gradient. Ⅰ. Ecological and RAPD Evidence

The former plant population survey has shown that three genetically-related species, Caraganamicrophylla Lam., C. davazamcii Sancz. and C. korshinskii Kom., form a geographical replacement series inNei Mongol Plateau. The present study on population distribution, taxonomy, morphology, development andgenetic structure demonstrated that the geographical distribution of these three species was successiveand in gradual change, thus forming a geographical cline which extended from the east to the west of NeiMongol Plateau. With an analysis of climate change over time, it was considered that the formation of thisgeographical cline was a result of plant adaptation to its natural environment.

Preliminary Study on Geographical Variation of Cytochrome b gene and ITS2-rDNA among Populations of Rhynchophorus ferrugineus

The Red Palm Weevil （RPW）, Rhynchophorus ferrugineus （Olivier）, （Coleoptera, Curculionidae, Rhynchophorinae）, is an invasive species that is originated from Southeast Asia. It has invaded Middle East, several countries of the Mediterranean Basin, Caribbean （Island of Curacao, Netherland Antilles）, Lebanon and United States of America （Laguna Beach, Orange County, California） during the last three decades where it attacks palm trees. This study investigated the geographical variation among geographic populations of RPW collected from twelve invaded countries using cytochrome b （Cytb） and ITS2 partial sequences. The comparison among the Cytb sequences resulted in three different haplotypes designated as HB 1 to HB3. The three haplotypes were subdivided into two phylogenetic groups according to their geographic positions： （1） the ＂Multi-Continent＂ group containing HB 1 haplotype detected in eight populations belonging to three different Continents such as Africa-Egypt, Asia-Kingdom of Saudi Arabia and Turkey and Europe-Spain, Italy, Greece, Cyprus and France, and （2） the ＂Asian＂ group includes four populations from Iran （harboring HB2 haplotype）, Pakistan, UAE, and Oman （harboring HB3 haplotype）. This mitochondrial pattern of genetic diversity suggests that the tested RPW populations subdivided genetically into different sub-populations under the influence of genetic drift. According to these results we concluded that the twelve studied RPW populations are originating from different source populations in the RPW area of origin.

AFLP analysis of genetic variation among three natural populations of horseshoe crab Tachypleus tridentatus along Chinese coast

The AFLP(amplified fragment length polymorphism) technique was used to analyze and compare the genetic diversity of Tachypleus tridentatus from three south-eastern coastal sites of China(Pingtan,Hong Kong and Beihai).Eight pairs of primers generated 361 loci,including 285 polymorphic loci.The ratio of polymorphic loci was 96.97%.Nei's genetic diversity index was 0.420 8 and the Shannon information index was 0.607 5,both of which were higher than that reported for many other arthropods.These results show that the genetic diversity detected was mainly caused by individual differences within a population.Genetic distance showed that the rational division of the three geographic populations of T.tridentatus along the south-eastern coast of China was not significant,in which the genetic distance was not proportional to the geographic distance.All three horseshoe crab populations may belong to a large group,and had a high degree of genetic similarity.The high level of genetic diversity obtained from the present AFLP analysis may be due to the large effective population size of the species in Chinese waters.

The Janus of macrophysiology： stronger effects of evolutionary history, but weaker effects of climate on upper thermal limits are reversed for lower thermal limits in ants

Species may exhibit similar traits via different mechanisms： environmental filtering and local adaptation （geography） and shared evolutionary history （phylogeny） can each contribute to the resemblance of traits among species. Parsing trait variation into geographic and phylogenetic sources is important, as each suggests different constraints on trait evolution. Here, we explore how phylogenetic distance, geographic distance, and geographic variation in climate shape physiological tolerance of high and low temperatures using a global dataset of ant thermal tolerances. We found generally strong roles for evolutionary history and geographic variation in temperature, but essen- tially no detectable effects of spatial proximity per se on either upper or lower thermal tolerance. When we compared the relative importance of the factors shaping upper and lower tolerances, we found a much stronger role for evolutionary history in shaping upper versus lower tolerance, and a moderately weaker role for geographic variation in temperature in shaping upper tolerance when compared with lower tolerance. Our results demonstrate how geographic variation in climate and evolutionary history may have differential effects on the upper and lower endpoints of physiological tolerance. This Janus effect, where the relative contributions of geographic variation in climate and evolutionary history are reversed for lower versus upper physiological tolerances, has gained some support in the literature, and our results for ant physiological tolerances provide further evidence of this pa^ern. As the climate continues to change, the high phylogenetic conservatism of upper tolerance may suggest potential constraints on the evolution of tolerance of high temperatures.

Wind effects on the migration routes of trans-Saharan soaring raptors： geographical, seasonal, and interspecific variation

Wind is among the most important environmental factors shaping birds＇ migration patterns. Birds must deal with the displacement caused by crosswinds and their behavior can vary according to different factors such as flight mode, migratory season, experience, and distance to goal areas. Here we analyze the relationship between wind and migratory movements of three raptor species which migrate by soaring-gliding flight： Egyptian vulture Neophron percnopterus, booted eagle Aquila pennata, and short-toed snake eagle Circaetus gallicus. We analyzed daily migratory segments （i.e., the path joining consecutive roosting locations） using data recorded by GPS satellite telemetry. Daily movements of Egyptian vultures and booted eagles were significantly affected by tailwinds during both autumn and spring migrations. In contrast, daily movements of short-toed eagles were only significantly affected by tailwinds during autumn migration. The effect of crosswinds was signifi- cant in all cases. Interestingly, Egyptian vultures and booted eagles showed latitudinal differences in their behavior： both species compensated more frequently at the onset of autumn migration and, at the end of the season when reaching their wintering areas, the proportion of drift segments was higher. In contrast, there was a higher drift at the onset of spring migration and a higher compensation at the end. Our results highlight the effect of wind patterns on the migratory routes of soaring raptors, with different outcomes in relation to species, season, and latitude, ultimately shaping the loop migration patterns that current tracking techniques are showing to be widespread in many long distance migrants.