Keynote speakers

Abstracts of Keynote Speeches

Joanna Jura-Morawiec: Advances in functional anatomy of the monocot tree Dracaena draco

Monocot dragon trees differ in anatomy from the dicot and gymnosperm trees. In this lecture, I will present our recent findings on the structure of stem and roots of Dracaena draco related to secondary growth and dragon’s blood secretion. I will conclude by summarizing our current work on the dragon tree leaf structure with reference to water uptake and storage. The findings shed some light on understanding how this monocot tree functions in a natural ecosystem.

Wenli Mei: Secondary metabolites from Dragon’s blood

Dragon’s blood is one of the renowned traditional medicines used in different cultures of world. These red saps and resins are derived from a number of disparate taxa. In China, Dracaena cochinchinensis and Dracaena cambodiana were the mainly plant resources of dragon’s blood. Phytochemical studies of dragon’s blood revealed that flavonoids are the main chemical constituents, while saponins, steroids, and phenols have also been identified as constituents inside it. Natural Dracaena resources have been destroyed severely owing to overexploitation. Our previous studies found an artificial induction method (authorized patent: ZL201310207182.5), which could induce the formation of the resin in the stem of D. cambodiana effectively. Phytochemical studies of dragon’s blood harvested 1 year after artificial induction by the patent method, revealed that the main chemical constituents are flavonoids similar to those in dragon’s blood produced naturally. Artificially induced dragon’s blood is expected to be the substituent of natural dragon’s blood.

Julian Jansen Van Rensburg: How to train your dragon: An archaeological approach to understanding the management and harvesting of the Dragon’s Blood tree in Antiquity

Historically, Dragon’s Blood could, according to the naturalist and natural philosopher Pliny the Elder (c. 1st century AD), be collected in the aftermath of the fight between the elephant and the dragon, when, upon their deaths, their blood mixed and created a resin with magical healing powers. While this story may seem fanciful it is worth bearing in mind that, even though Dragon’s Blood had been traded from at least the 1st century AD, very little was known about how it was obtained. Indeed, despite Soqotra having been the principal supplier of Dragon’s Blood from at least the mid-first century up until the post-medieval period there are virtually no records concerning how it was managed or harvested. Consequently, if we wish to progress in our studies of how Dragon’s Blood was harvested and managed in the antiquity, we need the information that only archaeology can furnish. Information that has long lain dormant amongst the relics of the Dragon Blood trees found on the island of Soqotra.

Raquel Vasconselos: Reptile community living on the dragon`s blood tree

We studied the reptile community living on the dragon`s blood tree Dracaena cinnabari from Socotra Island. Regardless of its patched and scarce actual distribution, we report the use of this tree as habitat by nearly half of the reptile community (11 endemic reptiles). Co-occurrence and network partition analyses demonstrate that this community is structured across the distribution of dragon blood trees, reflecting complex allopatric, vicariant and biotic-interaction processes. This Socotra endemic tree is currently threatened by overgrazing, overmaturity and climate change. Its protection and declaration as an umbrella species is expected to benefit the reptile community and to protect evolutionary processes that are partially driven by the ecological links between reptiles and this tree. To our knowledge, no tree species has been proposed as umbrella species for island endemics so far, highlighting the ecological particularities of Socotra Island.

Nadezhda Nadezhdina: Physiology of dragon trees revealed through sap flow research

Physiological similarities and differences between two remote D.species (Dracaena cinnabari, DC, and Dracaena draco, DD) were found based on in-situ and ex-situ sap flow studies conducted on young and mature plants. The same sap flow method was used namely the Heat Field Deformation, HFD, method with high time, space and direction resolution. Such common features of sap flow performance as alternative water pathways, low transpiration rates, ability to store and use atmospheric water in woody organs corresponded well with structural peculiarities of both DS as tree architecture, crown type, structure of transport system. The more xeric morpho-anatomical structure of DC leaves with a thicker level of wax and deeply sunken stomata provide its better water saving strategy with a shorter daily transpiration cycle compare with DD plants.