Time filter

Source Type

Hetterscheid W.L.A.,Von Gimborn Arboretum | Wistuba A.,Friedhofweg 4 | Amoroso V.B.,Central Mindanao University | Medecilo M.P.,De La Salle University - Manila | Claudel C.,Biocentre Klein Flottbek and Botanical Garden
Botanical Studies | Year: 2012

Amorphophallus natolii is described and illustrated as a new species from limestone hills near El Nido, Palawan island, Philippines. It differs most distinctly from other species of Amorphophallus with a densely hairy appendix by its much smaller size and dominant reddish pinkish colours of the spathe. A preliminary molecular analysis shows it to be in a basal position to a clade containing a few other species with similar appendices, to which it is also morphologically compared. It is certainly one of the most remarkable new discoveries in a genus containing ca. 200 species.

Suchrow S.,Biocentre Klein Flottbek and Botanical Garden | Pohlmann N.,Biocentre Klein Flottbek and Botanical Garden | Stock M.,Schleswig Holstein Agency for Coastal Defence | Jensen K.,Biocentre Klein Flottbek and Botanical Garden
Estuarine, Coastal and Shelf Science | Year: 2012

We analyzed long-term (19-21 years) surface elevation changes of salt marshes along the German mainland North Sea coast in a large and consistent data set (423 plots). Our aim was to determine the influence of 12 predictor variables, e.g. elevation, micro-topography and management data. For each plot, we measured elevation above sea level, once 1988-1990 and again 2009. The calculated surface elevation change per year (target variable SEC) was+0.6cmyr -1 on average. 85.8% of the plots showed positive SEC values. Although 11 predictors were significantly correlated to SEC, only five driving on different scales were included by the tree fitting algorithm when using regression tree analysis. The resulting tree model with 11 terminal nodes explained 45.7% proportion of the variance in SEC values. Plots tended to high SEC values when a) lying low in relation to mean high tide, b) being located in the northern regions of the study area, and c) lying in drainage ditches. d) Grazing management did account for SEC variance only in northern regions. e) SEC was enhanced on non-grazed plots lying high in relation to mean high tide. We concluded that most of the studied salt marshes may outpace a predicted sea-level rise of about 0.1-0.2cmyr -1, but barely half of the marsh areas might follow a sea-level rise of 0.6cmyr -1. Regression tree analysis is a useful approach for studying changes in elevation of salt marshes when considering various variables. © 2011 Elsevier Ltd.

Hetterscheid W.L.A.,Von Gimborn Arboretum | Claudel C.,Biocentre Klein Flottbek and Botanical Garden
Botanical Studies | Year: 2014

Background: Since the revision of Amorphophallus of Madagascar (Bot Jahrb Syst 121(1):1-17, 1999) several additional new species have been described. The recent discovery of another new species promted the preparation of a revised key as well as the description of the new species. Amorphophallus hildebrandtii, never restudied since its analysis by Engler in 1881, has been refound and restudied. Meanwhile molecular phylogenetic studies have provided new insights in the relationships of the endemic Madagascan species. Results: The new species Amorphophallus perrieri is described. A new revised key to the endemic Amorphophallus species of Madagascar is provided. An emended description of A. hildebrandtii is provided. A molecular phylogeny of the endemic Madagascan species of Amorphophallus is provided. Conlusions: The enigmatic character of a very short spadix in A. hildebrandtii has been confirmed, after it was thought for many years that it was artificially shorter in the holotype specimen than in nature. This was suggested by the fact that the spadix of the holotype is broken. The monophyletic character of the Madagascan endemic species clade remained unchallenged after analysis including all new species discovered recently, incl. the new species presented in this paper. © 2014 Hetterscheid and Claudel.

Suchrow S.,Biocentre Klein Flottbek and Botanical Garden | Stock M.,Schleswig Holstein Agency for Coastal Defence | Jensen K.,Biocentre Klein Flottbek and Botanical Garden
Estuaries and Coasts | Year: 2014

In salt marshes, species richness changes along environmental, disturbance and productivity gradients forming a complex network of abiotic and biotic factors. On 2,691 plots along 121 transects, we sampled vegetation along the German mainland North Sea coast (13 regions) during 1987–1989. Applying regression tree analysis (RTA), we now used this large data set to analyse variance in species richness (SRich) in relation to 13 explanatory variables varying on different scales. SRich (mean, 4.9 per m2) was significantly correlated to most variables. Only six variables were included in our final model, together explaining 68.5 % of variance in SRich, in hierarchical order: moisture, salinity, evenness, nitrogen, region and elevation. Predominantly, SRich was limited by environmental heterogeneity (moisture, salinity and nitrogen, each explained approx. 50 % variance). SRich tended to be high on plots exhibiting a combination of low moisture, salinity and nitrogen values, with high evenness—and especially high in some regions when plots were lying high in relation to mean high tide. Grazing regimes did not affect SRich significantly. In conclusion, our model showed that SRich in the study area was predominantly explained on a small scale and less along large-scale gradients. RTA proved suitable to identify the set of variables that mainly explained variance in SRich. Our tree model improves the understanding of richness patterns in salt marshes and can be used to predict species richness for the study area. Furthermore, our data provide a reference to detect richness changes due to, for example, management changes or sea level rise. © 2014, Coastal and Estuarine Research Federation.

Sankar-Thomas Y.D.,Biocentre Klein Flottbek and Botanical Garden | Lieberei R.,Biocentre Klein Flottbek and Botanical Garden
Plant Cell, Tissue and Organ Culture | Year: 2011

Levels of camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) were determined in different cultures of Camptotheca acuminata grown either in a Temporary Immersion System (TIS) or on solid medium. CPT was also detected in liquid culture medium. HPLC analysis showed significant differences in CPT contents in all tissues analysed and the highest CPT contents were found in shoots grown on solid medium and in TIS with a mean of 2. 2 and 2. 5 mg g -1 DW, respectively. The highest content of CPT detected in seedlings was 1. 96 mg g -1 DW; while that of somatic embryos at cotyledonary stage and regenerated plants were 0. 87 and 1. 23 mg g -1 DW, respectively. It was also shown that shoots cultured in TIS secreted substantial amount of CPT into the liquid medium. After 4 weeks in culture a mean of 6, 05 and 12, 6 μg g -1 FW were determined at 4 and 8 immersion cycles daily (IC d -1), respectively. This aspect opens new possibilities regarding the isolation of CTP using TIS culture systems. © 2011 Springer Science+Business Media B.V.

Loading Biocentre Klein Flottbek and Botanical Garden collaborators
Loading Biocentre Klein Flottbek and Botanical Garden collaborators