Past, Present, and Future Climate Change: Can Palaeoecology Help Manage a Warming World? - Biodiversity Conservation and Environmental Change - page 112

reorganisation can trigger a cascade of ecological effects, including changes in competitive
interactions, changes in predator-prey relations, and changes in the spread of pathogens, fur-
ther exacerbating the possibility of species reshuffling. Gradual changes in climate can lead
to abrupt changes in community structure when physiological thresholds are reached or
symbiotic relationships break down.
As species respond individualistically to climate change through differences in adaptation
and migration, reorganization of species assemblages will lead to new competitive inter-
actions, and some key mutualisms—for example between plants and their pollinators—will
be disrupted (Hampe 2011). All of these processes could lead to a reshuffling of species assem-
blages and the emergence of new combinations of species and new biological interactions
(Figure 5.11) (Parmesan et al. 2005, Williams and Jackson 2007). Such redistributions have
allowed survival through periods of dramatic climate change in the past; all of the species
alive today have been through the last glacial interglacial cycle, and though many animals
have become extinct since the last glacial maximum, there was most likely a human element
to these extinctions, and plant extinctions were rare until the past few centuries (Jackson and
Weng 1999, Barnosky et al. 2011, Willis and MacDonald 2011).
The occurrence of novel climates and no-analogue communities is predicted to increase
rapidly in the coming decades, driven not only by climate change, but also by the introduc-
tion of invasive alien species, which can outcompete indigenous species, disrupt pollination
mechanisms, or alter fire regimes, thereby exacerbating the interacting effects of changing
climate and land-use.
The prospect of no-analogue communities causes alarm over the future of favoured biomes
and habitat integrity, but equally, new assemblages could be considered adaptive, if new,
more resilient communities emerge and ecological processes are maintained (Walther et al.
2009). While persistence over long periods of time can imply resilience this is not always the
case and insight into ecosystem longevity can be misleading. Ecosystems arising since the
mid-Holocene might be better adapted to present and future conditions, and hence more
likely to survive (Jackson 2006). As we move into an era of novel climates, some of the most
resilient communities might be those that originated recently (Jackson 2006).
A landscape approach to resilience and adaptation in a perfect storm
Conservation planning in a changing climate is beset by uncertainty, with a range of scenar-
ios reflecting different possible future levels of greenhouse gas emissions (IPCC 2007). At the
same time, ecosystem loss, alien species, degradation and pollution are exacerbating climate
change impacts, threatening the provision of ecosystem services and driving many species to
the brink of extinction (Barnosky et al. 2013, 2014). Practical approaches are needed that deal
with urgent threats to biodiversity, while at the same time building towards long-term resil-
ience and sustainable ecosystem service provision (Glaser 2012, Griggs et al. 2013). Address-
ing the interlinked goals of biodiversity conservation and sustainability requires a landscape
approach, in which protected area networks are embedded in broader landscapes that con-
tribute to food security, water provision, and the cultural and spiritual aspects of human well-
being (see Chapters 6 and 7) (MEA 2005, Wu 2011, 2012).