Self-renewal Capacity of Several Species of the Genus Sternbergia Possessing Medicinal Properties

The present work dealt with sexual reproduction capacity of three relic species of the genus Sternbergia （family AmaryUidaceae） distributed in the Caucasus, i.e., Sternbergia lutea （L.） Ker Gawl. ex Spreng., Sternbergiafischeriana （Herb.） Roem and Sternbergia colchiciflora Waldst. ＆ Kit.. Under this study, the natural populations of species, which possess valuable medicinal and ornamental properties, have been assessed by experts as vulnerable, and S. colchiciflora is included in the red list of endemic plants of the Caucasus, as having status of the critically endangered species. The situation is aggravated by the poor self-regeneration capacity of these species, which is one of the main factors responsible for the sustainability of the population of this or that species in the wild. Self-regeneration capacity for sexual reproduction was investigated in the listed species of the genus Sternbergia using common methods of embryology and reproduction biology. In conditions of the National Botanical Garden of Georgia （NBGG）, the species S. lutea and S. fischeriana prove to be completely infertile and propagate vegetatively by bulblets, while S. colchiciflora revealed the ability for propagation by seed. Long-term conservation of seeds of the studied species S. colchiciflora in the Caucasus Regional Seed Bank （CRSB） and establishing of living collections of this species at the experimental plot were chosen as the method for safeguarding this critically endangered species.

Effects of fertilization and container-type on nutrient uptake and utilization by four subtropical tree seedlings

Seedling quality is important for subtropical tree species endangered by the degradation of natural habitats in southern China.At present,the cultural regime for raising these seedlings involving fertilizer levels and size of container is not clear.In this study,seedlings of three endangered species,red-seed tree(Ormosia hosiei),Zhejiang phoebe(Phoebe chekian gensis),and Zhejiang camphor(Cinnamomum japonicum)were evaluated along with red-bark oak(Cyclobalanopsis gilva)as a reference,a species which is not endangered.Seedlings were raised in 2.8,3.6,5.1,and 6.3 L containers and fertilizer applied at 1.0,2.0,3.0 and 4.0 kg m-3.Seedling height and leaf biomass increased in response to higher fertilizer levels while larger containers resulted in greater stem and root biomass.Root biomass of endangered species seedlings did not respond to neither treatments.Zhejiang phoebe seedlings responded to nitrogen and phosphorus uptake but red-seed tree seedlings were unaffected by any nutrient levels.Red-bark oak seedlings had high nitrogen-use efficiency.Based on the results,it is recommended using at least 5.1 L containers to culture Zhejiang phoebe and Zhejiang camphor seedlings with fertilizer at 3.0 kg m-3.Red-bark oak and red-seed tree seedlings should be cultured with 2.0 kg m-3 in smaller containers.

Autecology and conservation status of Magnolia sargentiana Rehder & Wilson(Magnoliaceae) in the Dafengding region,southern Sichuan Province,China

This paper reports the first population ecology study of the endangered Magnolia sargentiana Rehder ＆ Wilson （Magnoliaceae）. Magnolia sargentiana is a protected species in China, but little is known about its present status in the field. In 2007 and 2008, we surveyed the population and conservation status ofM. sargentiana in the Provincial Mamize Nature Reserve and the National Meigu Dafengding Nature Reserve, Sichuan Province, southwestern China. Natural regeneration is poor because of unfavorable environmental conditions and anthropogenic disturbances. Flower buds and bark ofM. sargentiana are used in traditional Chinese medicine and their collection by local people over the period 1983-1994 has led to marked population declines. The collection of flower buds and bark is now banned, but hewing branches for firewood and grazing continues to have a negative impact on the recovery of M. sargentiana populations. To protect the species, we require a ban on hewing branches, closure of primary forests to reduce the impact of humans and ungulates, better education of local people, and increased awareness of wildlife conservation.

Demography of the threatened endemic shrub, Arbutus pavarii,in the Al-Akhdar mountainous landscape of Libya

We sampled twenty populations of the vulnera- ble endemic shrub or tree, Arbutus pavarii Pampan., at different elevations and aspects within the A1-Akhdar mountainous region of Libya. Our sampling sites were at elevations ranging from 285 to 738 m above sea level, and several different habitats： vallies （locally known as wadis）, north- and south-facing slopes, and mountaintops. All individuals within each quadrat were studied. Population size and structure, and plant functional traits were assessed. None of the populations had a stable distribution of size classes. Some consisted mostly of small plants, with little or no fruit production; others consisted only of mid-sized and large plants, with high fruit production, but no juvenile recruitment. There was a significant increase in percent cover with increasing elevation; reproductive output （the number of fruits per branch and total number of fruits per individual） also generally increased with elevation. In some of these populations the lack of recruitment, and in others the failure to produce fruit, together constituted serious demographic threats. In light of these results, recommen- dations are made for conservation of this vulnerable endemic species.

Structure of a Semideciduous Seasonal Forest in the National Forest of Ipanema,Brazil:Contributing to the Floristic Knowledge of a Poorly Studied Protected Area

Studies on composition and structure generate crucial information for characterizing plant communities and planning conservation actions.There are still substantial knowledge gaps in Brazilian protected areas,preventing design programs to mitigate biodiversity loss.This is the case of the National Forest of Ipanema(Ipanema NAFO)in São Paulo state,Brazil,where plant diversity remains uncalculated.To help fill this gap,in 1-ha of a seasonal semideciduous forest(SSF)stand on the Araçoiaba hill,the authors sampled all woody stems with dbh≥5 cm in a total of 103 dead and 1,301 living plants representing 65 species,57 genera,and 31 families.The number of species and families was lower than old-growth SSF and,together with the land-use history,which suggests the community is a secondary stand.The initial species Guazuma ulmifolia,Machaerium stipitatum,Croton floribundus,and Aloysia virgata totalized 50%of the living stems,whereas 37%of the other species summed up only 1.8%.The high abundance of these initial species and the presence of the climax species Cariniana legalis,Holocayx balansae,Myroxylon peruiferum,Zanthoxylum caribaeum and others indicate that the community is in an intermediate to advanced successional stage.Three species are considered vulnerable to extinction and 27 of least concern.Ipanema NAFO is an important conservation unit,sheltering some plants vulnerable to extinction and others locally rare.This study adds to other few studies about the flora of Ipanema NAFO,helping to estimate its biodiversity and planning conservation actions.Additionally,it is a source for defining reference values for ecological restoration in the Atlantic forest.