The results obtained give a good overview of different temporal and spatial patterns in pollen data of the South Ecuadorian Andes. With this thesis, a further step towards a comprehensive
168 interpretation on palaeoenvironmental conditions during the past is taken, as it creates a basis for a carefully elaborated view on possible ecosystem dynamics in the light of global change and nature conservation issues. The results show, that the ecosystems of the South Ecuadorian Andes can in their natural state, generally cope well with even severe ecosystem changes, e.g. long dry and warm phases. In the study region of the Quimsacocha volcanic basin, marked vegetation changes did not take place since the early Holocene, as there are no changes in the overall composition but only in abundance patterns of plants.
However, the rate of change analysis of many sites across the South Ecuadorian Andes showed that nearly all sites were subjected to high velocities of change in taxa composition during the late Holocene. Due to human impact through increased use of fire, livestock grazing and the plantation of pine and Eucalyptus for the creation of forested sites in the páramo, the ecosystems seem to become more and more unbalanced and less resilient to face climate change.
This may have severe impacts that harm ecosystem dynamics in the future. A return to moderate human impact is therefore necessary to ensure the maintenance of important ecosystem services when ecosystems face global change, e.g. water retention capacity and food source. This is important, as climate predictions estimate that temperature rise will be faster at higher altitudes, varying from 2-6°C during a period of 100 years (1990-1999 to 2090-2099, depending on the model), and considering that the highlands constitute the most important water sources for the population of the tropical Andean countries (Bradley 2006).
The alarming expectations of climate change in the tropical Andes underline a great need of further palaeoenvironmental studies in this area.
Three years of modern pollen rain collection at selected sites in four surveyed vegetation types can only be a first step towards a more quantitative view on the topic. The analyses cannot capture the whole spatial and temporal dynamics of different environmental factors influencing pollen dispersal in this highly species-rich region. Also, any palaeoecological analysis gives only a small impression about a past environment and its changes throughout time and even a range of analyses may not be able to capture the full picture of past environmental dynamics for one region. However, the steady growth of data increases our knowledge about patterns and processes that help to understand the underlying mechanisms of why ecosystems changed in this way or the other and how these changes happen. We should not forget that palynology is one of the best tools we have to understand the landscapes we live in and form continuously, as it makes hidden patterns and processes of long-term ecosystem dynamics visible. It can help to predict ecosystem response in future climate and conservation scenarios, but moreover it also shows us nature as it is, was and should be conserved in all its complexity and beauty.
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