17 - The value and future of saproxylic diversity

Summary

In this final chapter we address some issues that we consider essential for the future of dead wood and its biodiversity. Until now we have mainly focused on the biological aspects of dead wood and have only to a limited extent considered wider topics such as ecosystem functions, the future of forest biodiversity, and the need to disseminate information about the fascinating life in decaying wood.

Value of saproxylic diversity

We are convinced that the intrinsic value of the saproxylic species is a sufficient motivation for their protection. We can be fascinated by the peculiarity, strangeness and beauty of saproxylic species, and learn tremendously from the intricate interactions between them. But species living in dead wood are also more directly valuable, by providing products, ecological services and option values.

Ecological functions, services and resilience

The species that colonize and utilize dead trees provide a central ecosystem service, namely the decay of organic matter and the connected recycling of energy and nutrients. The decomposer community, mainly fungi but assisted by a multitude of invertebrates, performs this service at no cost, allowing the other living components of forest ecosystems to thrive. There is a growing awareness that the global loss of species threatens the provision of services such as decay and nutrient turnover. One might ask if the overwhelming variety of species living in wood is really necessary from this perspective. Maybe it would be enough that a few key species are present and that the vast majority of species are actually redundant. In any specific case there is probably no clear and simple answer, but a growing body of evidence suggests that a critical feature in ecosystems is the level of resilience (see, e.g., Rockstr ö m et al., 2009 ). It is highly unlikely that the exact number of ‘necessary’ species could be dei ned despite the fact that several species may perform the same function, rather than all of them having critical and unique functions.