Ant protection of the nectaried fern Polypodium plebeium in central Mexico

Nectaries on fronds of Polypodium spp. have been studied previously only in cultivated specimens. We conducted field observations in middle-elevation forests in Mexico and found five ant species associated with nectaries of Polypodium plebeium and P. lepidotrichum. To investigate whether nectaries promote protection against herbivores, we performed ant-exclusion experiments with nectary-bearing ferns (P. plebeium) and other ferns without nectaries (Polypodium plesiosorum, P. furfuraceum, and Phlebodium pseudoaureum). When ants were excluded from the developing fronds of Polypodium plebeium, damage from foliage-feeding sawfly and lepidopteran caterpillars was significantly greater than in control fronds. Ferns without nectaries did not show a difference in damage between ant-excluded and control fronds. Our results demonstrate that fern nectaries can support ant defense of the plant body as do the extrafloral nectaries of many angiosperms.     

中国蕨类植物区系的初步研究

对中国蕨菜植物区系组成和科属的地理成分进行了统计分析,结果表明：中国蕨类植物区系具有区系成分丰富、起源古老、区系联系广泛、热带性质显著以及特有现象不明显的特点。     

Succession of secondary forests affected by pine wilt disease in western Japan followed on vegetation maps

Abstract. Succession, changes in the distribution pattern of forest vegetation, and Pinus forest survival following pine wilt disease were clarified based on phytosociological analysis and vegetation maps. Survival of Pinus forests was restricted to the early successional stages, which were located on ridges and the upper part of slopes. Subsequent to pine wilt disease, the succession progressed from early to late substages of Pinus forest, mixed deciduous and evergreen Quercus, to evergreen Quercus forest. Succession occurs in abandoned pine forests which apparently are in a bad state and are vulnerable to attacks by pine wilt disease.     

Riqueza y Distribución Ecológica de Especies de Pteridofitas en la Zona del Río Yavarí-Mirín, Amazonía Peruana

We studied the ecological distribution of pteridophytes (ferns and fern allies) along eight 8-km transects covering 12.7 ha in Peruvian Amazonia. Subunits of 200 m² of the transects have previously been classified into four different forest types, and here we document and quantify the floristic differences among these forest types. Pteridophytes have been suggested as an indicator group to classify rain forest habitats, but this requires that the ecological preferences of the species are well documented and consistent across geographic regions. Here we analyzed in detail the distribution and diversity patterns of 130 species across the four rain forest types. Relative species abundance and species diversity were similar among some of the forest types and differed among others, but the species composition differed markedly. Our results largely confirmed the earlier interpretation of the edaphic preferences of the pteridophyte species in western Amazonia. This supports the proposition that deterministic processes have an important role in influencing the floristic composition of Amazonian forests.     

Seedling Mortality in Hawaiian Rain Forest: The Role of Small‐Scale Physical Disturbance1

Most montane rain forests on the island of Hawaii consist of a closed canopy formed by Cibotium spp. tree ferns beneath an open canopy of emergent Metrosideros polymorpha trees. We used artificial seedlings to assess the extent to which physical disturbance caused by the senescing fronds of tree ferns and the activities of feral pigs might limit tree regeneration. Artificial seedlings were established terrestrially (N= 300) or epiphytically (N = 300) on tree fern stems. Half of the seedlings on each substrate were in an exclosure lacking feral pigs and half were in forest with pigs present. After one year, the percentage of seedlings damaged was significantly greater among terrestrial seedlings (25.7%) than epiphytic seedlings (11.3%). Significantly more terrestrial seedlings were damaged in the presence of pigs (31.3%) than in the absence of pigs (20.0%). Senescing fronds of tree ferns were responsible for 60.3 percent of the damaged seedlings. Physical disturbance is potentially a major cause of seedling mortality and may reduce the expected half‐life of a seedling cohort to less than two years.     

广西蕨类植物新记录(Ⅱ)

该文报道了广西蕨类植物新记录7种,即蕨萁(Botrychium virginianum)、澜沧凤了蕨(Coniogramme serrulata)、筱英凤尾蕨(Pteris xiaoyingae)、卵果双盖蕨(Diplazium ovatum)、厚叶实蕨(Bolbitis hainanensis)、河口实蕨(B.hekouensis)和粗齿鳞毛蕨(Dryopteris juxtaposita),并列出了这些种的标本引证和地理分布。     

海南植物区系的多样性

记载海南维管束植物的多样性,表明蕨类植物区系已有古生代和中生代的孑遗,又有白垩纪以来的现代蕨类,它们都存在着许多特有种;裸子植物则以泛热带成分及华夏成分为主;有花植物包括全球植物区系8个植物区的成分,而以热带成分及全球性分布成分最多。最后,文章分析了海南植物区系多样性的地史背景及自然条件的因素。     

A new species in the Elaphoglossum petiolatum complex (Elaphoglossaceae) from Mexico

Elaphoglossum trichomidiatum is described from northeastern Mexico. The new species is a member of theE. petiolatum comples, which is widespread in tropical America, Africa, Southeast Asia, and the Pacific Islands. It is unique in the complex and in sectionLepidoglossa in bearing trichomidia on the abaxial blade surface.