Ecosystems

State of the World’s Plants and Fungi: 2 in 5 plants are threatened by extinction (Part 2)

In a previous post, I wrote about a recent review on extinction risk and threats to plants and fungi that contributed to the State of the World’s Plants and Fungi (SOTWPF) report. The first afternoon session of the SOTWPF symposium focused on the recent research projects that aim to assess and predict extinction threats of plants and fungi.

The major threats to plants and fungi reported in the SOTWPF report.

Dr Bryn Dentinger from the Natural History Museum of Utah and University of Utah (USA) first introduced the knowledge gaps in understanding fungi extinctions and conservation methods and presented the ectomycorrhizal porcini mushroom, Boletus edulis as a case study. At the moment, the average rate of describing new fungi is 1,500/year and so, it would take roughly 2,390-5,730 years to completely document Fungi. His lab has been studying the genetic diversity and dispersal of Boletus edulis, found high levels of inbreeding. His research suggests that high habitat turnover and habitat management on large spatial scales is needed to reduce future extinction risks to these fungi.

Next, Dr John Halley from the University of Ioannina (Greece) presented the species-area relationships and plant extinctions. It is fundamental that larger areas can support more biodiversity and conversely, smaller areas support less biodiversity. Quick and large habitat losses can either remove all individuals of a species or reduce the populations that will disappear later, leading to an extinction debt. This extinction debt varies according to the remaining area. A few years ago, he highlighted gaps in scientific knowledge of extinction debt in plant communities and he emphasised again in his presentation that plant extinctions might be very well underestimated at the moment. 

Ludmilla Figueiredo, a PhD student from the University of Würzburg (Germany) looks at the effect of extinctions from individuals to metacommunities (e.g. there would be a lag of pollinator extinctions and plant extinctions). She presented her recent publication on understanding extinction debts and presented her latest mechanistic models which estimate extinction, evolutionary change and rescue under different climate change scenarios. Whilst population recovery is important in evolutionary rescue, species cannot “save themselves” without conservation management tools. 

Extinction debt from 15 studies plotted according to the ecological organizational level and the time scale of the debt. Source: Figueiredo et al. 2019

The last speaker in this session was Dr Barnaby Walker from Royal Botanic Gardens, Kew (UK) who explained that extinction risk assessments have been biased and how artificial intelligence can “fill in the gaps” and help with assessment prioritisation. He highlighted plant extinction risk assessments with methods such as Preliminary Automated Conservation Assessments (PACA), deep neural network (IUC‐NN) and the Rapid Least Concern app. Machine learning offers great many opportunities to help prioritise conservation efforts but it also needs to be “supervised”. 

Extinction is not necessarily a gloomy topic

The Q&A session consisted of considering conservation tools on extinction debt, effects of habitat loss, possibility of colonisation credit and the reliability of models. Whilst extinction is a normally gloomy topic, this session set out a new roadmap for scientists. As extinction can be a long process, it is hard to experimentally study it but DNA sequencing and robust models offer useful insights. A lot more information is needed about fungi, their life cycle, distribution, genetic diversity and also environmental drivers of their distributions. Conservation assessments of plants have been increasing in the last few years but the international community needs to continuously identify underrepresented regions and plant families and re-prioritise. 

You can re-watch the entire session here (3:18:15).

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