[en] The genus Cicerbita Wallr. of the tribe Cichorieae-Asteraceae is revised for Pakistan and Kashmir. A broader generic concept of the genus is accepted and in all 11 species have been recognized including 3 new species viz. Cicerbita astorensis, Roohi Bano and Qaiser, C. alii, Roohi Bano and Qaiser and C. gilgitensis Roohi Bano and Qaiser. 5 new combinations, including 3 at species and 2 at varietal level have also been proposed. An artificial key to all the species is provided. Latin diagnosis, illustrations of newly described species, world wide and local distribution and ecological notes of all the species are also furnished. (author)

[en] The reproductive effort of some annual and perennial plant species was investigated with respect to successional sequence, habitat conditions and plant size. in the psammosere succession (dune succession), the reproductive effort (RE) of Cressa cretica and A triplex griffithii was significantly greater in the early stage compared to that in late succession. Likewise, in relation to lithosere succession, Sporobolus arabicus. Pluchea lanceolata and Vernonia cenerescens all showed high reproductive effort in early part of succession compared to that of late succession. The annuals (S. arabicus and P lance/ala) exhibited greater reproductive effort compared to the perennial species Vernonia cinerescens. Examination of the Impact of site differences on reproductive effort showed that four grasses including Selaria intermedia, Chioris harbata, Cenchrus hiflorus, and Eragroslis pilosa were found to have significantly (P<0.05) greater reproductive effort in site 1 (near cultivated field), compared to site 2 (a vacant lot), which had low nutrient level compared to site 1. The reproductive effort of Sonclius asper (a composite) did not exhibit significant difference between sites. The investigation of relationships between plant size (volume) and reproductive effort of Solanuin forskalii, Senna holosericea and Heliolropium ophioglossum showed positive correlations between plant size and reproductive effort. Solanum forskalii and Senna holosericca, in particular, exhibited a close association in this respect. It is concluded that: 1) RE is greater in early compared to late succession, 2) RE changes with the habitat and 3) there seems to be a direct relationship between RE and plant size. (author)

[en] The point pattern analysis was applied for analyzing plant spatial distributions, predicting species associations, and providing an efficient representation of ecological process. Pinus tabulaeformis forest, Betula platyphylla forest, Betula albo-sinensis forest, Larix principis-rupprechtii forest in the Xiaowutai Mountain were selected as research objects, and four 50m×50m quadrats were set up. We measured diameter at breast height (DBH) and location of trees, and analyzed population structure, spatial distribution pattern, intraspecific and interspecific associations of dominant tree species in four forest communities by point pattern analysis and Monte-Carlo simulation test, in order to provide a theoretical basis and development strategies for natural resource protection in the areas. The results showed that a total of 166 vascular plant species in 49 families were recorded in quadrats. Betula platyphylla had the largest average and maximum of DBH among all plant species. Betula albo-sinensis had the largest average tree height, while Betula platyphylla had the maximum tree height among all plant species. Pinus tabulaeformis presented random distribution within 13.5m and cluster distribution outside 13.5m. Betula platyphylla presented random distribution on all the scales. Betula albo-sinensis and Larix principis-rupprechtii presented cluster distribution on the small scales and random distribution on the larger scales. The study also revealed that Betula platyphylla and Acer mono on the scale of 2.4m-22.5m, and Betula albo-sinensis and Sorbus alnifolia on the scale of 3.5m-7.5m had a significant negative correlation. Furthermore, Pinus tabulaeformis and Larix principis-rupprechtii were expanding populations mainly affected by intraspecific competition. Betula platyphylla and Betula albo-sinensis were stable populations respectively affected by interspecific competition, intraspecific and interspecific competition. Spatial distribution and species associations of four forest types were regulated by dispersal limitation and environmental heterogeneity in the Xiaowutai Mountain. We should effectively adhere to sustainable principles for protecting natural forest resources. (author)

[en] The main objectives of the LICC project are to address the potential effects of a future climatic change on (semi-) natural terrestrial ecosystems and landscapes in Europe; six case studies are covered: alpine regions, boreal and subartic regions, Mediterranean region, fluvial systems, wetlands and coastal dunes. Preliminary findings showed a serious lack in fundamental ecological knowledge. Assessment of potential effects involved changes in water and sediment fluxes, changes in the vegetation cover, species response, dispersal and migration in a fragmented landscape and modification of climate impacts by man

[en] In Estonia, reforesting has been considered to be the most sustainable way of restoring the productivity of land damaged by oil shale mining. As distinct reforestation alternatives give different results, three alternative ways of reforesting oil shale opencasts are compared: natural succession, and planting seedlings of either Scots pine or black alder. The present research shows that the use of unassisted natural succession is the most sustainable way of reforesting oil shale opencasts

[en] The article discusses the results of studies on ecological succession in the zone of alienation (Vetkovskij area of the Gomel' region). The lands of this zone have not been used for agricultural purposes. The connection between characteristics of regeneration ecosystems and ecological condition of agricultural landscape is established. The change of vegetation in the course of succession is considered. Plant associations which are formed in the zone of alienation are described. (authors)

[en] Seed morphology plays an important role for the taxonomic purposes, but in spite of the importance and stability of seed characters in systematics, very little work has been done on seed morphology of Begonia. The seeds of Begonia are small and not differentiated easily with the naked eye. In fact, they are so small that observation of many of their taxonomically important features is possible only with a scanning electron microscope (SEM). In this paper, the external morphology of the seeds of 23 Nepalese Begonia species, belonging to five sections (Diploclinium, Monopteron, Platycentrum, Putzeysia and Sphenanthera) was studied with SEM techniques. It has been revealed that the differences in seed characteristics were not sufficient to use for sectional delimitation of Nepalese Begonia, but helped to separate the Begonia at species level. (author)

[en] A predator-prey system, depending on several parameters, is investigated for bifurcation of equilibria, Hopf bifurcation, global bifurcation occurring saddle connection, and global existence and non-existence of limit cycles, and changes of the topological structure of trajectory as parameters are varied. (author). 8 refs, 4 figs

[en] The landscape of the Kalahari Desert is changing as the indigenous Acacia erioloba E.Mey. is being replaced by the invasive Prosopis spp. Although both species are phreatophytic, the disproportionately large taproot of Prosopis enables it to survive extreme moisture stress. δ¹³C values were determined on annually resolved Prosopis and Acacia erioloba samples to investigate adaptation to changing edaphic conditions. The results confirm that the Acacia erioloba sample died during a period of water stress

No abstract available