Rising sea levels have been associated with human migration and behavioral shifts throughout prehistory, often with an emphasis on landscape submergence and consequent societal collapse. However, the assumption that future sea-level rise will drive similar adaptive responses is overly simplistic. While the change from land to sea represents a dramatic and permanent shift for preexisting human populations, the process of change is driven by a complex set of physical and cultural processes with long transitional phases of landscape and socioeconomic change. Here, we use reconstructions of prehistoric sea-level rise, paleogeographies, terrestrial landscape change, and human population dynamics to show how the gradual inundation of an island archipelago resulted in decidedly nonlinear landscape and cultural responses to rising sea levels. Interpretation of past and future responses to sea-level change requires a better understanding of local physical and societal contexts to assess plausible human response patterns in the future.
Clonal propagation of Quercus suber via somatic embryogenesis is an alternative to conventional tree propagation methods; however, complete maturation of somatic embryos is considered the major bottleneck for mass propagation of Quercus species. During somatic embryogenesis, embryo development and maturation are controlled by signaling pathways that integrate information from genetic and epigenetic programs as well as hormonal signals. Therefore, in this study genes were identified related to epigenetic regulation and the abscisic acid (ABA) pathway during development and maturation of cork oak somatic embryos. A total of eight expressed sequence tags were obtained of genes encoding a 9-cisepoxycarotenoid dioxygenase (NCED), two histone deacetylases (HDA6 and HDA19), two histone monoubiquitinases (HUB1 and HUB2), a histone H3 kinase (AUR3) as well as genes related to chromatin remodeling processes PICKLE and VP1/ABSCISIC ACID INSENSI-TIVE 3-LIKE 1 (VAL1). The analysis of the expression patterns of selected genes during different developmental stages indicated that QsNCED3 may play a role in ABA synthesis during embryogenesis. The change in the expression levels for all seven genes associated with epigenetic regulation showed that QsHUB1 and QsHUB2 may have a role in ABA signalling while QsHDA6 and QsHDA19 could act in different pathways than in Arabidopsis. Furthermore, expression levels of QsAUR3 indicated that histone phosphorylation is an early epigenetic mark in Q. suber somatic embryos while QsPICKLE and QsVAL1 may be necessary for the correct development of cork oak somatic embryos.
During development of multicellular organisms, cells become differentiated by modulating different programs of gene expression. Cells have their own epigenetic signature which reflects genotype, developmental history, and environmental influences, and it is ultimately reflected in the phenotype of the cells and the organism. However, in normal development or disease situations, such as adaptation to climate change or during in vitro culture, some cells undergo major epigenetic reprogramming involving the removal of epigenetic marks in the nuclei followed by the establishment of a different new set of marks. Compared with animal cells, biotech-mediated achievements are reduced in plants despite the presence of cell polypotency. In forestry, any sustainable developments using biotech tools remain restricted to the lab, without progressing to the field for application. Such barriers in the translation between development and implementation need to be addressed by organizations that have the power to integrate these two fields. However, a lack of understanding of gene regulation is also to blame for this barrier. In recent years, great progress has been made in unraveling the control of gene expression. These advances are discussed in this chapter, including the possibility of applying this knowledge in forestry practice.
Small islands tend to experience exacerbated environmental/social vulnerabilities, due to isolation, size and a small resource base. The response of social communities to environmental stress can be addressed by compiling palaeoecological proxies for land management alongside archaeological records. This paper presents pollen data from four new late Holocene sequences that lie around sea-level on the Isles of Scilly (south-west England), to understand the impact of coastal change on island communities. Interpretation of sequences near the coastal zone can be confounded by problems in disentangling human impact from maritime and wetland influence. Multivariate analysis is used to separate samples influenced by maritime conditions and wetland development from 'inland' human land management practices. During the Bronze Age clearance of woodland resulted in an intensively managed pastoral system and archaeological datasets indicate that maritime resources formed an important part of the subsistence economy. Despite coastal change that resulted in loss of land area and reduced the extent of the intertidal zone, the pollen data and evidence from existing archaeological data show continuity through later prehistory and into the medieval period. The archaeological data and pollen evidence point towards a highly resilient community that employed a mixed and varied subsistence base.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.