Innovative approaches to the preservation of forest trees

AbstractThe recent acceleration of actions to conserve plant species using ex situ and in situ strategies has revealed the need to understand how these two approaches might be better developed and integrated in their application to tree species. Here we review some of the recent successes relating mainly to tree seed biology that have resulted in the development and application of innovative actions across five areas: (i) the expansion of living collections to conserve threatened tree species in sufficient numbers to ensure a broad genetic diversity in their progeny; (ii) the generation of viability constants to enable estimates to be made of storage longevity of tree seeds in the dry state; (iii) improvement in the diagnosis of tree seed storage behaviour through the development of predictive models, reliable prognoses of desiccation tolerance and use of botanical information systems, such as GIS, to correlate information on species distribution and their physiological characteristics; (iv) advances in storage preservation biotechnology to enhance the future application of cryopreservation procedures to recalcitrant species in biodiversity hotspots where many are under threat of extinction; and (v) integration of ex situ and in situ conservation approaches to ensure that best practice in horticultural and forestry are combined to maintain or enhance genetic diversity, especially in high value species and those with small and vulnerable populations. These actions can lead to greater impact if supported by greater efforts to create seed banks and to collate databases world-wide so that data, knowledge and collections are more available to the scientific, forestry and NGO communities. Throughout this review we have used examples from the mega-biodiversity countries of Brazil and China, as a way of illustrating wider principles that can be applied in many countries. Future development of current research approaches, the adherence to conservation policy and the expanding needs for education are also considered briefly

Seed size influence on germination responses to light and temperature of seven pioneer tree species from the Central Amazon

In Amazon secondary forests are dominated by pioneer species that typically produce large amounts of small and dormant seeds that are able to form a persistent soil seed bank. Seed dormancy in this group of species is overcome by environmental conditions found in open areas, such as high irradiation or alternating temperatures. Nevertheless, a variety of germination responses to environmental factors is known among pioneers; some of them may germinate in diffuse light or in darkness condition at constant temperature. Seed mass can be considered as one of the factors that promotes this variety. Regarding species with very small seeds, it seems that the trigger for germination is light and for larger seeds temperature alternation may be a more important stimulus. In this study we established a relationship between seed mass and germination response to light and alternating temperature for a group of seven woody pioneer species from the Amazon forest. We found that an increase in seed mass was followed by a decrease in the need for light and an increase in the tolerance to alternating temperatures. Understanding germination strategies may contribute with the knowledge of species coexistence in high diverse environments and also may assist those involved in forest management and restoration.Na Amazônia as florestas secundárias são dominadas por espécies pioneiras que, normalmente, produzem grandes quantidades de sementes pequenas, dormentes e capazes de formar bancos de sementes no solo. A dormência neste grupo de espécies é superada pelas condições ambientais de áreas abertas, como alta irradiação ou alternância de temperaturas. No entanto, uma variedade de respostas de germinação aos fatores ambientais é conhecida entre as pioneiras; algumas germinam em luz difusa ou no escuro sob temperatura constante. Um dos fatores promotores desta variedade é a massa das sementes. Parece que para as espécies com sementes muito pequenas, o estímulo para que ocorra germinação é a luz e, para sementes maiores, a alternância de temperatura pode ser um estímulo mais importante. Neste estudo, estabeleceu-se uma relação entre a massa das sementes e a resposta de germinação à luz e temperatura para sete espécies pioneiras arbóreas da floresta amazônica. Descobrimos que o aumento na massa da semente foi acompanhado por diminuição da necessidade por luz e aumento da tolerância à alternância de temperatura. Compreender estratégias de germinação pode contribuir para os conhecimentos sobre a coexistência de espécies em ambientes altamente diversos e também pode ajudar aos pesquisadores envolvidos no manejo e restauração florestal

Establishment of babassu in pasture in Para, Brazil

International audienc