Plants, pests and diseases
New Zealand plant biodiversity is recognised for its richness, distinctiveness of species and unique assemblages. This national treasure has enormous social and economic value and is integral to the healthy function of our natural ecosystems and the beauty of many of our landscapes.
The explosion of plantings of native species in our gardens, along new highways, and through recreation areas reflects the attractiveness, diversity and general adaptability of New Zealand flora. Progress, albeit less than some may have anticipated, has also been made in identifying and extracting compounds from native plants for human health and other purposes. Native plants and their extracts are appearing increasingly on restaurant menus.
These direct economic benefits, however, are modest compared to the high value New Zealanders and international tourists place on the splendour of our forests and forest remnants. I was fortunate to be raised on a farm that bordered the Waipoua Forest with its magnificent kauri and, at that time, healthy populations of kiwi, kākā, kererū and kākāpō.
Unfortunately, as we highlight in this edition of Discovery, much of our indigenous plant biodiversity is under significant challenge to the extent that a few species face the threat of extinction. In this issue we update you on the research we are doing to address some of these threats. The iconic kauri is threatened by a new fungal invasion and varroa mite is impacting the essential pollination service provided by bees.
Finding cost-effective solutions that can be applied in environments that range from city suburbs to remote steep valleys in a national park presents a complex, multifaceted problem for our research teams. Quick-fix solutions are rare as is exemplified by the almost 20 years of research we have undertaken on controlling possums, perhaps the most visible threat to our native plants. However, as Dan Tompkins and his team are showing with a BGG vaccine, we are continuing to make steady progress in developing effective solutions to complement and ultimately replace 1080 for the control of possums and other invasive species.
In 2001 the Parliamentary Commissioner of the Environment appealed in a report, ‘Weaving resilience into our working lands: future roles for native plants on private land’, for an integrated approach to policy development to address the loss of native plant biodiversity, in particular regarding land use. Land-use change and management, as I observed an earlier edition of Discovery, has a pivotal role in New Zealand’s future agricultural outputs, response to climate change, water yield and quality, and landscapes. The trends for some aspects of plant biodiversity, as well as other indicators such as water quality, are one indication that the policy mix is not yet right.
Your feedback and suggestions are most welcome on any of the topics presented in Discovery or on our website.