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Optimal understanding of biodiversity threats must consider the effects of population size and habitat quality on population viability. I examined the effects and relative importance of these factors for the performance of two endangered hemiparasitic plants, Melampyrum cristatum and M. arvense in Finland. I surveyed 18 M. cristatum and 14 M. arvense populations. Both habitat quality and population size influenced the performance of M. cristatum. By contrast, the performance of M. arvense was determined by habitat quality, but not influenced by population size. Habitat quality was improved in managed M. cristatum populations, which translated into greater hemiparasite performance in these populations. Degradation of suitable habitats has likely decreased the performance of the two endangered hemiparasites, resulting in reduced population sizes. The results highlight the importance of considering simultaneously population size effects and habitat quality. Habitat management seems to be the key to sustain or increase the viability of the hemiparasite populations, but the timing and intensity of management should be considered.
Emergence of seedlings from cattle dung collected in different seasons from grasslands of the Flooding Pampa was analysed. The objective of this work was to find out (1) how high the proportion of seeds from exotic species in the seeds spread by cattle dung is, and (2) what the forage quality of the species spread through cattle dung is. Fresh dung was collected in late spring and late summer from three grasslands. Seedling emergence from dung was done in greenhouse conditions. Seedling number, forage quality and origin of the species were determined. We found 121 plant species growing in the grasslands. The number of species emerging from dung was 41. Twenty-four and 36 species emerged from dung collected in late spring and late summer, respectively. Nineteen species were common for both seasons. There were 5.33 ± 0.26 and 1.00 ± 0.15 (mean ± SE) native and exotic species, respectively, per dung sample (22.50 g dry weight) collected in late spring. From the dung collected in late summer emerged 7.70 ± 0.31 and 2.63 ± 0.18 native and exotic species per sample, respectively. Carex spp., Cyperus spp. and Juncus spp. (native species) were the most abundant (95%) in dung collected in late spring. In dung collected in late summer Cynodon dactylon (an exotic species) represented 76% and Carex spp., Cyperus spp. and Juncus spp. represented 9%. The most abundant species emerged from dung were of low forage quality and thus are considered weeds in crop fields. Seed propagation through cattle dung helps to explain the increment of exotic species in the Flooding Pampa grasslands under grazing. The results are relevant for the range managers who normally move the cows between stubble crop fields and grasslands, spreading through dung seeds of species of different origin and quality.
The polyploid origin and colonization history of Iris aphylla in central and southeastern Europe were investigated by means of karyological and AFLP analyses. The study indicated two chromosome races within I. aphylla based on chromosomal numbers 2n = 24 and 2n = 48. The overall chromosome counts and determined ploidy suggest tetraploidy as the most common ploidy level for this species in Europe. Only one diploid I. aphylla population was found, with a restricted distribution area in the Slovak Karst. The analyses showed that tetraploids arose independently at least three or more times in the past. The karyological results were in agreement with the AFLP data and strongly suggested that migration between the two Carpathian Mts. sites occurred recently via the Dukielska Pass. The low number of AFLP fragments unique to each population supports the hypothesis of recent range expansion and colonization of different environments in central Europe by I. aphylla. All populations were genetically depauperated and had 0–3 unique bands, indicating that not enough time elapsed for many unique fragments to form through mutation. We also observed relatively high and significant differentiation between the one diploid and all investigated tetraploid I. aphylla populations (ΦST = 0.470, p < 0.001). The high and significant values of genetic differentiation can be explained by several factors such as anthropopression and natural succession, which have fragmented the open calcareous habitats in central Europe.
Random Amplified Polymorphic DNA (RAPD) markers were used to measure the levels of genetic variation and patterns of the population structure within and among the five remaining populations of Ceratopteris pteridoides, an endangered aquatic fern in China. Fourteen RAPD primers amplified 101 reproducible bands, with 34 (33.66%) of them being polymorphic, indicating low levels of genetic diversity at the species level. The level of genetic diversity within the populations was considerably lower, with the percentage of polymorphic bands (PPB) ranging from 16.83% to 24.75%. AMOVA analysis revealed a low level of genetic variation (30.92%) among the populations. The UPGMA cluster of 72 samples detected that individuals from the same population did not form one distinct group, indicating high levels of gene flow between the populations. A Mantel test showed no significant relationship between genetic distance and geographic distance (r = 0.2166). Our results were similar to those obtained in an earlier ISSR analysis. Thus both RAPD and ISSR markers have comparable sensitivity, and could be employed to assess the partition of genetic diversity within and among populations. Several factors including clonal growth, inbreeding, high spore dispersal and the extensive hydrologic connectivity among populations which facilitate long-distance gene flow, might have played an important role in maintaining the genetic structure of the populations. In view of the genetic information currently available, we recommend establishing as many in situ conservation spots as possible and the cross transplanting of plants between populations in order to increase gene flow and preserve the genetic resources of the species.
We studied the natural history as well as the conservation status of the first-known population of Polygala balansae in Europe (Granada, SE Spain). In the study area, we located only one population occupying a small patch of 1920 m2, between 120 and 160 m a.s.l., with 246 mature individuals. The species is classified as Critically Endangered (CR), under the following criteria: severely fragmented, inferred continuous decline, small population size, and continuing decline inferred from the number mature individuals. The main threats over the population are: spreading subtropical tree-crops and encroachment of human settlements for tourist purposes, plus natural causes (drought, wild or human-mediated fire, limited dispersal, poor recruitment/ reproduction/regeneration, high juvenile mortality, low densities and restricted range). Finally, passive and active conservation measures are proposed in order to guarantee the survival of the species.
A taxonomic revision of Hedysarum species (Fabaceae) recognized as a part of the H. gmelinii complex is presented. One widespread species is recognized here and two new combinations are proposed: H. gmelinii var. dahuricum (Turcz. ex B. Fedtsch.) R. Sa and H. gmelinii var. setigerum (Turcz. ex Fisch. & Mey.) R. Sa, based on morphological studies of herbarium specimens and seed coat sculpturing characteristics. The name H. gmelinii is lectotypified. A taxonomic conspectus for the three taxa, including a list of synonyms, information on type specimens, morphological differentiation, ecological characteristics, and distribution data are given. Additionally, the problems of former treatments of sections Multicaulia and Subacaulia within Hedysarum are discussed.
Peucedanum ozhatayiorum Akpulat & E. Akalin is described and illustrated as a new species from northeast Anatolia, Turkey. It is similar to P. caucasicum and P. longibracteolatum but differs from them by having a slender, scabroid stem; scabroid leaves; a fibrous collar; deciduous bracts; persistent unequal bracteoles; green-purple petals; and up to 10 vittae in the dorsal side of mericarps.
Salvia ekimiana F. Celep & Doğan sp. nova (Lamiaceae) is described and illustrated from Turkey. It is confined to Yozgat in central Anatolia where it grows in open Pinus sylvestris forest and alpine steppe. The diagnostic morphological characters from closely similar species are discussed.
The typification of Rubus scissus W.C.R. Watson is corrected. This name is to be applied to R. nessensis Hall subsp. scissoides H.E. Weber nom. inval., and R. scissus auct. is redescribed here as a new species R. ochracanthus H.E. Weber & Sennikov. Three species names earlier published with two types (R. christianseniorum H.E. Weber, R. insulariopsis H.E. Weber, R. stormanicus H.E. Weber) are validated here by type designation.
Raphiocarpus maguanensis Y.M. Shui & W.H. Chen, a new species of Gesneriaceae from Yunnan Province, China, is described and illustrated. The new species is compared to the fairly similar R. longipedunculatus.
Arisaema linearifolium G. Gusman & J.T. Yin, a member of the section Sinarisaema, is described as a new species native to northern Yunnan, China. Its morphological characters are discussed and compared with those of morphologically similar species.