Scatter hoarding by corvids （crows, jays, magpies, and nutcrackers） provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throu...Scatter hoarding by corvids （crows, jays, magpies, and nutcrackers） provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germin- ation and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns （Quercus spp.） on Santa Cruz Island. We use a large behavioral data set on the birds＇ behavior in combination with seedling surveys and spatial analysis to determine whether 1） island scrub jays disproportionally cache seeds in specific habitat types, and 2） whether the preferred habitat type is suitable for oak regeneration. Our results show that the jays nonrandomly cache acorns across the landscape; they use chaparral and coastal sage scrub disproportionally while avoiding open and grassy areas. The areas used most often for caching were also the areas with the highest oak seedling densities. We discuss the potential role of these findings for the recovery of Santa Cruz Island＇s oak habitat since the 1980s.展开更多
We aimed with this study to assay the allelopathic potential of wheat genotypes in inhibiting germination and initial growth of sourgrass (Digitaria insularis) resistant to the herbicide glyphosate. Two experiments we...We aimed with this study to assay the allelopathic potential of wheat genotypes in inhibiting germination and initial growth of sourgrass (Digitaria insularis) resistant to the herbicide glyphosate. Two experiments were installed under greenhouse conditions: the first one aimed to assay the potential of wheat genotypes in inhibiting emergence and initial growth of two test plants, and the second aimed to evaluate the potential of those wheat genotypes which performed better at the first experiment, inhibiting the emergence and initial growth of sourgrass biotypes resistant to the herbicide glyphosate. Five doses of aqueous cool-extracted extract from 32 wheat genotypes were applied to tomato and cucumber (Experiment 1) aiming to identify the ones with higher inhibitory effect. The five most inhibitory wheat genotypes were selected for Experiment 2, where the same doses of extract were applied on sourgrass. For both experiments, shoot fresh and dry mass, as well as water content, were assessed. Sourgrass germination is affected by wheat extracts, but initial seedling growth seems not to be affected;wheat genotypes differ in terms of their allelopathic potential in inhibiting sourgrass germination;wheat presents little inhibitory effect on sourgrass.展开更多
Electroantennograms(EAGs)were obtained for Holcocerus insularis Staudinger exposed to the female sex pheromone extracts and standard compounds.The male response profiles to the female sex pheromone extracts were raise...Electroantennograms(EAGs)were obtained for Holcocerus insularis Staudinger exposed to the female sex pheromone extracts and standard compounds.The male response profiles to the female sex pheromone extracts were raised with the increasing of glands.Of compounds tested 12 elicited conspicuous EAG responses,mostly as negative deflections about 2～6 mv in amplitude with a time courses of 2.0～2.7 second.Z 9 tetradecenyl acetate(Z9 14:Ac)and Z 5 dodecenyl acetate(Z5 12:Ac) could elicit highest EAG responses,but C 16 ,C 18 acetates lowest.It revealed that sex pheromone components simillar to C 12 , C 14 acetates probably existed in the pheromone of Holcoceris insularis Staudinger.The dosage\|response curve of Z9 14:Ac roughly took a“S” shape.展开更多
报道了桦木科（Betulaceae）鹅耳枥属（Carpinus L.）一新种——香港鹅耳枥（C. insularis N. H. Xia, K. S. Pang ＆ Y. H. Tong）.香港鹅耳枥与太鲁阁鹅耳枥（C. hebestroma Yamamoto）及多脉鹅耳枥（C. polyneura Franch.）相似,但...报道了桦木科（Betulaceae）鹅耳枥属（Carpinus L.）一新种——香港鹅耳枥（C. insularis N. H. Xia, K. S. Pang ＆ Y. H. Tong）.香港鹅耳枥与太鲁阁鹅耳枥（C. hebestroma Yamamoto）及多脉鹅耳枥（C. polyneura Franch.）相似,但习性灌木状,叶具13 ~ 16 对侧脉,先端锐尖,边缘锯齿的芒尖较短,果苞宽半卵形或半卵形,长8 ~ 14 mm,小坚果顶端密被长柔毛且疏具树脂状腺体,与后两者易于区别.展开更多
缺齿鼹属(Mogera)隶属于哺乳纲(Mammalia)劳亚食虫目(Eulipotyphla)鼹科(Talpidae),是一类严格适应地下生活的“真鼹”,常栖息于林间草地或邻近农地中。缺齿鼹外形上与鼹属(Talpa)物种十分相似,其齿式为:3.1.4.3/2.1.4.3=42(Ziegler,197...缺齿鼹属(Mogera)隶属于哺乳纲(Mammalia)劳亚食虫目(Eulipotyphla)鼹科(Talpidae),是一类严格适应地下生活的“真鼹”,常栖息于林间草地或邻近农地中。缺齿鼹外形上与鼹属(Talpa)物种十分相似,其齿式为:3.1.4.3/2.1.4.3=42(Ziegler,1971),下颌比鼹属物种缺少一个门齿,故而得名缺齿鼹。当前分类体系认为缺齿鼹属共包含9个物种,其中5种在中国有分布(魏辅文,2021):大缺齿鼹(M.robusta Nehring,1891)、海岛缺齿鼹(M.insularis Swinhoe,1862)、台湾缺齿鼹(M.kanoana Kawada et al.,2007)、华南缺齿鼹(M.latouchei Thomas,1907)和钓鱼岛鼹(M.uchid‐ai Abe et al.,1991)。华南缺齿鼹和海岛缺齿鼹的分类和分布仍存较大争议。展开更多
文摘Scatter hoarding by corvids （crows, jays, magpies, and nutcrackers） provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germin- ation and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns （Quercus spp.） on Santa Cruz Island. We use a large behavioral data set on the birds＇ behavior in combination with seedling surveys and spatial analysis to determine whether 1） island scrub jays disproportionally cache seeds in specific habitat types, and 2） whether the preferred habitat type is suitable for oak regeneration. Our results show that the jays nonrandomly cache acorns across the landscape; they use chaparral and coastal sage scrub disproportionally while avoiding open and grassy areas. The areas used most often for caching were also the areas with the highest oak seedling densities. We discuss the potential role of these findings for the recovery of Santa Cruz Island＇s oak habitat since the 1980s.
文摘We aimed with this study to assay the allelopathic potential of wheat genotypes in inhibiting germination and initial growth of sourgrass (Digitaria insularis) resistant to the herbicide glyphosate. Two experiments were installed under greenhouse conditions: the first one aimed to assay the potential of wheat genotypes in inhibiting emergence and initial growth of two test plants, and the second aimed to evaluate the potential of those wheat genotypes which performed better at the first experiment, inhibiting the emergence and initial growth of sourgrass biotypes resistant to the herbicide glyphosate. Five doses of aqueous cool-extracted extract from 32 wheat genotypes were applied to tomato and cucumber (Experiment 1) aiming to identify the ones with higher inhibitory effect. The five most inhibitory wheat genotypes were selected for Experiment 2, where the same doses of extract were applied on sourgrass. For both experiments, shoot fresh and dry mass, as well as water content, were assessed. Sourgrass germination is affected by wheat extracts, but initial seedling growth seems not to be affected;wheat genotypes differ in terms of their allelopathic potential in inhibiting sourgrass germination;wheat presents little inhibitory effect on sourgrass.
文摘Electroantennograms(EAGs)were obtained for Holcocerus insularis Staudinger exposed to the female sex pheromone extracts and standard compounds.The male response profiles to the female sex pheromone extracts were raised with the increasing of glands.Of compounds tested 12 elicited conspicuous EAG responses,mostly as negative deflections about 2～6 mv in amplitude with a time courses of 2.0～2.7 second.Z 9 tetradecenyl acetate(Z9 14:Ac)and Z 5 dodecenyl acetate(Z5 12:Ac) could elicit highest EAG responses,but C 16 ,C 18 acetates lowest.It revealed that sex pheromone components simillar to C 12 , C 14 acetates probably existed in the pheromone of Holcoceris insularis Staudinger.The dosage\|response curve of Z9 14:Ac roughly took a“S” shape.
基金supported by the Project"Compilation of the Chinese Version of Flora of Hong Kong"(AFCD/SQ/110/11)Agriculture,Fisheries and Conservation Department,the Hong Kong Special Administrate Region
文摘报道了桦木科（Betulaceae）鹅耳枥属（Carpinus L.）一新种——香港鹅耳枥（C. insularis N. H. Xia, K. S. Pang ＆ Y. H. Tong）.香港鹅耳枥与太鲁阁鹅耳枥（C. hebestroma Yamamoto）及多脉鹅耳枥（C. polyneura Franch.）相似,但习性灌木状,叶具13 ~ 16 对侧脉,先端锐尖,边缘锯齿的芒尖较短,果苞宽半卵形或半卵形,长8 ~ 14 mm,小坚果顶端密被长柔毛且疏具树脂状腺体,与后两者易于区别.
文摘缺齿鼹属(Mogera)隶属于哺乳纲(Mammalia)劳亚食虫目(Eulipotyphla)鼹科(Talpidae),是一类严格适应地下生活的“真鼹”,常栖息于林间草地或邻近农地中。缺齿鼹外形上与鼹属(Talpa)物种十分相似,其齿式为:3.1.4.3/2.1.4.3=42(Ziegler,1971),下颌比鼹属物种缺少一个门齿,故而得名缺齿鼹。当前分类体系认为缺齿鼹属共包含9个物种,其中5种在中国有分布(魏辅文,2021):大缺齿鼹(M.robusta Nehring,1891)、海岛缺齿鼹(M.insularis Swinhoe,1862)、台湾缺齿鼹(M.kanoana Kawada et al.,2007)、华南缺齿鼹(M.latouchei Thomas,1907)和钓鱼岛鼹(M.uchid‐ai Abe et al.,1991)。华南缺齿鼹和海岛缺齿鼹的分类和分布仍存较大争议。
