In both case studies the change in sedimentary style and dramatic increase in the rate of floodplain sedimentation can
be related to the agricultural history of the catchments; however, this change to a human-driven geomorphological system varies in date by at least 2300 years. Notebaert and Verstraeten (2010) comment that there is seldom proof of a “direct relationship” of accelerated alluviation with either climate or anthropogenic activity; however, this is bound to be the case at the regional level, but not if individual small catchments are used which have high resolution dating and independent vegetation histories as is the case here. Geomorphologists have recognised a Global discontinuity in Holocene alluvial stratigraphies from all continents, JQ1 cost except Antarctica. However, this has been dated to the mid to late Holocene in the Old World and parts of the New World, and
to the period of European colonisation of other parts of the New World. In all these cases the principal, but not sole cause is arable agriculture. It is argued that this is likely to be an enduring signal as it exists well outside potentially future-glaciated areas and as sediment yields fall the sedimentary boundary will be preserved in river terraces due to channel incision. This will make a marked lithological and sedimentological Fluorouracil research buy difference between this terrace and earlier Pleistocene terraces which will also include a biological turnover with the appearance of new taxa, largely domesticates, and synanthropes. Discussions of the Anthropocene have to accommodate these data and this may have important implications Phosphatidylinositol diacylglycerol-lyase for the status and demarcation of the Anthropocene as a period in Earth System history. The authors very much thank N. Whitehouse, S. Davis, R. Fletcher, M. Dinnin and J. Bennett for assistance in the field and L. Ertl
for assistance with figure preparation. “
“Forest ecosystems in pristine, less managed, landscapes are often considered to be a natural reflection of resource limitations and species competition or facilitation; however, the footprint of ancient human activities and its influence on nutrient reserves should be considered when evaluating the nature and composition of contemporary ecosystems. The occurrence of open spruce (Picea abies L.)-lichen (Cladina spp.) forests in subarctic Sweden is one such ecosystem. This forest type was an enigma to plant scientists who considered these unique forests to be a natural phenomenon created by intrinsic edaphic and climatic limitations of the region ( Wahlgren and Schotte, 1928 and Wistrand, 1965). However, more recent analyses suggested that these forests may be a product of continual use of fire as a land management tool over a 2000–3000 year period ( Hörnberg et al.