I am studying the multitrophic interactions which affect the diversity and structure of plant communities. The research focuses on the interactions between organisms from more than two trophic levels, in natural, semi-natural and managed plant assemblages. In particular, I am interested in how non-pathogenic fungi in plants affect the insect herbivores which also feed on those plants. The two categories of fungi under investigation are root-inhabiting arbuscular mycorrhizas (AM fungi) and foliar endophytes. Natural plant communities include those regenerating from seedbanks on abandoned land such as that which has been taken out of agricultural production under the set-aside scheme. Semi-natural communities include areas where mixtures of wildflower seeds have been sown, in order to recreate species-rich meadows on land or on green roofs. Managed communities involve golf courses and football pitches, and the production of high-quality turfgrass. The applications of my work are in the development of novel microbial methods for plant protection against pests and diseases, the biological control of weeds, and the conservation of very rare plants and insects.
Fungal fruiting and climate change
My late father (Ted Gange) collected records of fungal appearance in an area around Salisbury Wiltshire from 1950 to 2015. This 30 km radius area covers all of the New Forest and Salisbury Plain. We now have over 70,000 detailed records of fungal occurrence and the records have been deposited in the Fungal Records Database of the British Isles. We are continuing analysis of this data set, looking at how fungal phenology has changed over the last 65 y and whether certain groups or species of fungi have altered their host associations. We have published our results so far in Science, PNAS, Ecography, Ecology and Fungal Ecology.
Amanita rubescens is a common fungus in our data base that has shown significant changes in phenology and host associations over the last 65 years.
Insect/endophyte interactions (funded by NERC and the Nuffield Foundation)
There has been a great deal of work with endophytic fungi in grasses and their interactions with insect herbivores. However, much less is known about endophytes in herbs and their interactions with insects. The diversity of fungi within herbaceous plants is high and we have found that vertical transmission of fungi, from one generation of plants to the next, via the seed, can occur. Certain endophytes can elicit remarkable chemical changes in their hosts and these can have dramatic effects on insect herbivores.
Interactions between arbuscular mycorrhizas and phytophagous insects (funded by NERC and the EU).
We were the first to show that the presence of arbuscular mycorrhizal (AM) fungi in plant root systems can affect the growth, reproduction and survival of foliar- and root-feeding insects. We have also found that the effects of these fungi extend beyond herbivores to influence the behaviour of pollinating and parasitoid insects. Furthermore, these effects are apparent at the evolutionary level, where we found that AM fungi can influence levels of insect dietary specialisation.
British plant families with high mycorrhizal affinity have more specialist insects that eat thhem. Re-drawn from Gange et al Ecology Letters 5: 11-15.
Biological control of weeds (funded by NERC)
Our latest NERC project is looking at how we can improve the efficacy of a rust fungus, recently released by CABI to control Himalayan balsam. We are working with CABI and the University of Reading to find out if manipulating the endophyte and mycorrhizal fungi within balsam can influence the performance of the rust. Furthermore, we have found that balsam has a serious effect on the soil microbial community composition which would reduce the chances of native vegetation re-establishing if balsam was eradicated. Thus, we are trying to use AM fungi to improve soil quality and improve native vegetation restoration.
This work was part of a gold medal winning display at the 2017 Chelsea Flower Show.
Impatiens glandulifera is one of the most problematic weeds in the UK
Sports turf biocontrol (funded by BBSRC, the Leverhulme Trust and industry)
A major problem with the majority of golf greens in the U.K. is the presence of Annual Meadow Grass (Poa annua) as a weed species and the accompanying loss of bent grass (Agrostis species). Annual Meadow Grass (AMG) is a problem because it provides an uneven putting surface, is less resistant to drought than bentgrass and is attacked by a wide range of fungal pathogens. This means that large amounts of fungicide are applied to golf greens and we need to find ways of biologically reducing AMG abundance and hence fungicide application. We have performed microbial (bacteria and AM fungi) surveys of golf green soil and have found that levels of these organisms are often extremely low indeed. In addition, we have found that the abundance of AM fungi is positively related to the abundance of the desirable grasses and negatively related to that of AMG. Therefore, we are studying ways of increasing AM fungal levels in turfgrass, in order to provide a biological method for the production of high-quality, disease-resistant grass. This work could have applications to golf courses all over the world, and we have recently extended it to football pitches, where we are working with a number of Premier League clubs.
Golf greens are challenging plant communities to work with, plants are only about 4mm tall!
Green roof biodiversity (funded by NERC and industry)
Green roofs may be planted with Sedum matting or fitted with a substrate that is allowed to colonise naturally. These roofs could provide new habitats in areas which are currently lacking wildlife habitats, could act as wildlife corridors or stepping stones, linking existing habitats, could facilitate movement and dispersal of wildlife and be refuges for rare and declining species. Plant establishment is often poor and we know this is due to a depauperate soil food web that lacks critical invertebrate and microbial components. We are trying to find ways of enhancing the soil microbial community in a sustainable manner, so as to lead on to improved plant establishment and growth.