Trends and Distributions
We use field recorded data to understand how species distributions and the environment are changing over time.
Species distributions today are the outcome of past events. This legacy of the past combines with (i) global change (climate change, pollution, tree disease etc.) and (ii) management decisions in today's landscape, to affect species into the future. This complexity of time-scales needs to be understood to make informed choices that protect biodiversity.
How do species distributions and diversity today compare to those 50, 100 or even 300 years ago? We used a novel source of biodiversity information - lichen epiphytes preserved on the structures of pre-industrial timber framed houses - to reconstruct species loss from the pre- to the post-industrial landscape (Yahr et al. 2011, 2014). Focussing on midland and southern England, an estimated 70-80% of epiphytes were lost across this 'Anthropocene' boundary (Ellis et al. 2011, 2018), as a consequence of industrial pollution and abandonment and destruction of traditionally-managed ancient woodland. This suggests that conservation targets established in UK's post-industrial landscape (e.g. since the 1970s Nature Conservation Review) under-represent the landscape's ecological potential as a consequence of this shifted baseline (Ellis et al. 2018).
- Ellis, C.J., Yahr, R. & Coppins, B.J. (2011) Archaeobotanical evidence for a massive loss of epiphyte species richness during industrialisation in southern England. Proceedings of the Royal Society B, 278: 3482-3489.
- Ellis, C.J., Yahr, R. & Coppins, B.J. (2018) Quantifying the Anthropocene loss of bioindicators (lichen epiphytes) for an early industrial region (England): an equitable baseline for biodiversity restoration. Biodiversity and Conservation, 27: 2363–2377.
- Yahr, R., Coppins, B.J. & Ellis, C.J. (2011) Preserved epiphytes as an archaeological resource in post medieval vernacular buildings. Journal of Archaeological Science, 38: 1191-1198
- Yahr, R., Coppins, B.J., & Ellis, C.J. (2014) Quantifying the loss of lichen epiphyte diversity from the pre-industrial Exmoor landscape (south-west England). The Lichenologist, 46: 711-721.
Focussing on lichen epiphytes, our work explores the relative importance of large-scale drivers (climate, pollution, landscape habitat quality) in explaining species distributions (Ellis & Coppins 2010a,b), while showing also that patterns of species richness are determined by historic habitat structure (Ellis & Coppins 2007, 2009). This historic effect is caused by a lag-time in the response of populations to landscape change, which represents an 'extinction debt', warning us that species rich sites may be vulnerable to ongoing biodiversity loss despite their protection. Analysis of record data shows that rare and threatened lichens have continued to decline over the last 50 years (Ellis & Coppins 2019), while simulations suggest that their remnant populations may be too small and isolated to recover into regenerated woodland (Ellis 2017), making translocation a necessary option.
- Ellis, C.J. (2017) When is translocation required for the population recovery of old-growth epiphytes in a reforested landscape? Restoration Ecology, 25: 922-93.
- Ellis, C.J. & Coppins, B.J. (2007) 19th Century woodland structure controls stand-scale epiphyte diversity in present-day Scotland. Diversity & Distributions, 13: 84-91.
- Ellis, C.J. & Coppins, B.J. (2009) Quantifying the role of multiple landscape-scale drivers controlling epiphyte composition and richness in a conservation priority habitat (juniper scrub). Biological Conservation, 142: 1291-1301.
- Ellis, C.J. & Coppins, B.J. (2010a) Integrating multiple landscape-scale drivers in the lichen epiphyte response: climatic setting, pollution regime and woodland spatial-temporal structure. Diversity and Distributions, 16: 43-52.
- Ellis, C.J. & Coppins, B.J. (2010b) Partitioning the role of climate, pollution and old-growth woodland in the composition and richness of lichen epiphytes in Scotland. The Lichenologist, 45: 601-61.
- Ellis, C.J. & Coppins, B.J. (2019) Five decades of decline for old-growth indicator lichens in Scotland. Edinburgh Journal of Botany, 76: 319-331
Lichen experimental translocations are used to reinforce meta-populations
Future Distributions and Scenarios
We have been at the forefront of bioclimatic modelling for lichens (Ellis 2019), coupling species distributions with climate change scenarios and assessing exposure to future climate as the loss/gain or spatial shift in a species' suitable bioclimatic space (Ellis et al. 2007a,b). Focussing on epiphytes (Ellis 2013) we have increasingly linked exposure to large-scale climate change with local shifts in habitat structure, e.g. as a consequence of tree disease (Binder & Ellis 2008; Ellis et al. 2014). We have published a comprehensive bioclimatic analysis for 382 British lichen epiphytes (Ellis et al. 2015), which was made available to explore the joint effects of climate and woodland change (including management options), supported by a demonstration piece to inform strategic planning for Glasdrum National Nature Reserve.
We developed spatial and time-series comparisons to test and confirm the validity of assumptions underlying bioclimatic models (Braidwood & Ellis 2012; Ellis et al. 2014), and we have identified key areas of uncertainty associated with future non-analogue climates (Ellis & Eaton 2016). Using RBGE's regional gardens as experimental sites, we have quantified how the lichen response to future climate will be affected by non-analogue combinations of temperature, moisture and irradiance, realised at high-resolution (monthly) time-scales (Ellis et al. 2017; Ellis 2019).
Our latest work is showing how lichen communities (Ellis & Eaton 2021a), through to individual growth rates (Ellis 2020), are affected by woodland microclimates, and therefore how landscapes and stand structures can create refugia used to offset negative climate change for threatened species (Ellis and Eaton 2021b).
- Binder, M.B. & Ellis, C.J. (2008) Conservation of the rare British lichen Vulpicida pinastri: climate change, habitat loss and strategies for mitigation. The Lichenologist, 40: 63-79.
- Braidwood, D. & Ellis, C.J. (2012) Bioclimatic equilibrium for lichen distributions on disjunct continental landmasses. Botany, 90: 1316-1325.
- Ellis, C.J. (2013) A risk-based model of climate change threat: hazard, exposure and vulnerability in the ecology of lichen epiphytes. Botany, 91: 1-11.
- Ellis, C.J. (2019) Climate change, bioclimatic models and the risk to lichen diversity. Diversity, 11: 54.
- Ellis, C.J. (2019) Interactions of climate and solar irradiance can reverse the bioclimatic response of poikilohydric species: an experimental test for Flavoparmelia caperata. The Bryologist, 122: 98-110.
- Ellis, C.J. (2020) Microclimatic refugia in riparian woodland: a climate change adaptation strategy. Forest Ecology and Management, 462: 118006.
- Ellis, C.J., Coppins, B.J. & Dawson, T.P. (2007a) Predicted response of the lichen epiphyte Lecanora populicola to climate change scenarios in a clean-air region of northern Britain. Biological Conservation, 135: 396-404.
- Ellis, C.J. & Eaton (2016) Future non-analogue climates for Scotland's temperate rainforest. Scottish Geographical Journal, 132: 257-268.
- Ellis, C.J. & Eaton, S. (2021) Climate change refugia: landscape, stand and tree-scale microclimates in epiphyte community composition. The Lichenologist, 53: 135-148.
- Ellis, C.J. & Eaton, S. (2021) Microclimates hold the key to spatial forest planning under climate change: cyanolichens in temperate rainforest. Global Change Biology, 27: 1915-1926.
- Ellis, C.J., Eaton, S., Theodoropoulos, M., Coppins, B.J., Seaward, M.R.D. & Simkin, S. (2014) Response of epiphytic lichens to 21st Century climate change and tree disease scenarios. Biological Conservation, 180: 153-164.
- Ellis, C.J., Eaton, S., Theodoropoulos, M., Coppins, B.J., Seaward, M.R.D. & Simkin, J. (2015) Lichen Epiphyte Scenarios. A Toolkit of Climate and Woodland Change for the 21st Century. Royal Botanic Garden Edinburgh. ISBN: 978-1-91087-00-5.
- Ellis, C.J., Geddes, H., McCheyne, N. & Stansfield, A. (2017) Lichen epiphyte response to non-analogue seasonal climates: a critique of bioclimatic models. Perspectives in Plant Ecology, Evolution and Systematics, 25: 45-58.
- Ellis, C.J., Yahr, R., Belinchón, R. & Coppins, B.J. (2014) Archaeobotanical evidence for climate as a driver of ecological community change across the anthropocene boundary. Global Change Biology, 20: 2211-2220.
Good to Know
The Royal Botanic Garden Edinburgh includes three regional gardens - Benmore, Dawyck, and Logan - which occupy contrasting climates. Staff at these Gardens have helped to maintain lichen experiments that are used to relate species growth to the climate. This provides a solid basis for understanding the future effects of climate change.