Islands in the sky

Roof top gardens aren’t just a quasi hipster architect’s dream concept, but really help insulate and cool buildings, capture rainwater and provide locally sourced food. Scientists are now extending their uses  to help conserve endangered plant species.

Learn more about how roof top gardens are being used to help with species conservation in Melbourne

Go to full New Scientist article

 

Featured image: The Hallelujah Mountains from Avatar – floating islands that circulate slowly in  magnetic currents like icebergs at sea (image from www.wallconvert.com)

This article was also published on Prof Andy Lowe’s research group’s blog https://biodiversityrevolution.wordpress.com

Shifting restoration’s mindset away from the ‘Garden of Eden’

There has been a recent recommendation to set restoration baselines as pre-degradation ecological communities. However this is a nostalgic aspiration, akin to restoring the ‘Garden of Eden’. It is unrealistic, expensive and does not acknowledge ecosystem change. Restoration should respond to the current drivers of biodiversity loss by addressing declines in ecosystem function and provisioning of ecosystem services.

Earth is in a land degradation crisis. Roughly a third of the world’s land is degraded, which is adversely impacting biodiversity and ecosystem function. If combined into one geopolitical boundary, theseFederated States of Degradia’ would have a landmass bigger than Russia and a population exceeding 3 billion, largely consisting of the world’s poorest and most marginalized people.

The extent and impact of land degradation has sparked many multilateral agreements with ambitious restoration targets. In 2011, the Partnership on Forest & Landscape Restoration proposed The Bonn Challenge – to restore 150 million ha of degraded land by 2020. This target was extended to 350 million ha by 2030 at the September 2014 UN Climate Summit. In January 2015, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) proposed a thematic assessment of land degradation and restoration. At the December 2015 Paris Climate Conference, a further 100 million ha of restoration by 2030 was committed to – the African Restoration Initiative (AFR100).

garden-of-eden
“Adam et Ève au Paradis Terrestre” by Wenzel Peter, showing wonderful biodiversity but an unrealistic ideal.

These ambitious goals are essential to focus global effort on such significant challenges. Restoration projects tend to assess their success based either on simplistic input metrics (e.g. number trees planted, number of stems per hectare) or projects aim for outcomes that are difficult to quantify (e.g. improve ecosystem integrity). Using inputs as success proxies are risky as they may not reflect actual ecological success and ‘motherhood’ outcome statements are difficult to quantify and too complex.

There has been recent emphasis to set a reference baseline to guide restoration success (Kotiaho et al 2016). It has been recommended that restoration should aim to put back pre-degradation ecological communities. We suggest (Breed et al 2016) that this baseline is a nostalgic aspiration, akin to restoring the ‘Garden of Eden’, rather than an improved standard. Gearing restoration to emulate pre-degradation habitats is unrealistic, can be prohibitively expensive and does not acknowledge current and future environmental change. Instead of this ‘Garden of Eden’ baseline, we argue that restoration should respond to the current drivers of biodiversity loss by addressing declines in ecosystem function and concentrate on the provision of ecosystem services.

While a baseline that prescribes a list of pre-degradation species is a good place to start, it does not take into account the dynamism of ecological communities. Communities have always been and are constantly in flux, particularly during the Anthropocene. Species  migrate, evolve and go extinct. Invasive species may be so prevalent and naturalised that they are impossibly costly to remove. Land allocated for restoration is often so altered from its pre-degradation state that it will no longer serve as habitat for the pre-degradation community. Many local, native species can be prohibitively difficult to propagate. Present-day climate change may necessitate the use of non-local genotypes and even non-local native species to improve restoration outcomes.

Newer, forward-thinking approaches may result in the generation of novel genepools or even novel ecosystems. Projects should focus on targets that are relevant to their overarching goals. For example, if a project has been established to improve pollination services then the abundance and diversity of insect pollinators could be their metric of success. As highlighted by Breed et al (2016), restoration should focus on building an ecological trajectory towards functional, self-sustaining ecosystems that are resilient to climate change and provide measurable ecosystem-service outcomes – as emphasized by IPBES.

Article by Martin Breed, Nick Gellie, Peter Mortimer, Andrew Lowe

From School of Biological Sciences and the Environment Institute, University of Adelaide, North Terrace, SA 5005, Australia; Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Heilongtan, Kunming 650201, Yunnan, China; and World Agroforestry Centre, East and Central Asia Regional Office, Kunming, 650201 Yunnan, China

Article re-edited from original published in The Conversation; https://theconversation.com/were-kidding-ourselves-if-we-think-we-can-reset-earths-damaged-ecosystems-59972

This article was also published on Prof Andy Lowe’s research group’s blog https://biodiversityrevolution.wordpress.com

References

Breed MF, Mortimer P, Lowe AJ (2016) Biodiversity: ‘Eden’ baseline is unrealistic. Nature 534: 469.

Kotiaho JS, ten Brink B, Harris J (2016) Land use: A global baseline for ecosystem recovery. Nature 532: 37. doi:10.1038/532037c

Local is not always best

The use of local seed is widely advocated for habitat restoration and is based on the premise that locally sourced seed will be the best adapted for the local conditions at restoration sites.

However, a ‘local is best’ seed sourcing practise (where seed for planting establishment is only sourced from native habitat within a few km of the restoration site) misses two important points, which may be seriously impacting on restoration outcomes, particularly resilience in the face of future environmental and climate change.

The first potential problem is that there is a serious risk of establishing  populations that will not harbour sufficient evolutionary potential for future environmental change (or ‘genetic ghettos‘ as they have been termed. In addition, strict adherence to ‘local is best’ protocols may encourage the selection of poor seed sources, when genetically healthier sources further a field may produce a more efficacious restoration result. This may serve to perpetuate the number of small inbred populations across highly degraded landscapes that are unlikely to persist in the long term.

The second issue is that environmental conditions that drive local adaptation can change very rapidly, and sourcing only local seed may fix adaptations to past environments. The environment is continually changing at different rates and scales, from diurnal to decadal to Milankovitch (100,000 year) cycles. The most notable recent environmental change (at least in geological time periods) has been the emergence from the last ice age, over the last 10,000 years ago or so. During the ice age the atmosphere was significantly cooler and dryer than it is today, but since that time plants (and their genes) have redistributed across the landscape, some over thousands of kilometres and some at exceptionally rapid rates. In addition, recent anthropogenically forced environmental change (e.g. climate change, habitat fragmentation, increased salinity, irrigation, and heavy metal deposition) will have  dramatically changed selection pressures.

In the face of rapidly changing environments it is pertinent to ask how “local environments” should be defined in contemporary landscapes, especially for long-lived species such as trees. In many regions of the world the conditions under which a 200-year-old tree was established are now very different to those existing today, and it could be legitimately argued that source material from more distant (geographically and ecologically) populations may harbour adaptations that more closely match the environment of the focal restoration site today.

The answer to provenance selection for future adaptive potential surely then lies in mimicking these natural gene flow and evolutionary dynamics.

So can we improve the selection of seed provenances to maximize evolutionary potential in restoration plantings? And can we facilitate long-term adaptive response to contemporary and future selection pressures? In answering this question it is informative to note two main processes, the migration of genetic adaptations between populations (through gene flow) and the evolution of new adaptive variants, which have allowed species to keep pace with environmental change naturally. The answer to provenance selection for future adaptive potential surely then lies in mimicking these natural gene flow and evolutionary dynamics.

For some species gene flow via pollen and seed has been documented to occur over tens, and in some rare cases over hundreds of kilometres. However many species are now limited in their capacity to disperse propagules (both pollen and seed), following habitat alteration and fragmentation. Gene flow in many species is leptokurtic – a term which means that most seed falls close to he mother plant, but that a significant proportion moves over much longer distances (see fig below)

EVA_157_f3

To simulate the natural mixing of genes during a restoration programme, it would be necessary to restore populations using a mixture of material sampled at different distances from the focal site, a practise defined as composite provenancing. This ‘composite provenance’ would be predominantly composed of locally sourced material, taken from genetically healthy stock, but would also incorporate local and ecogeographically matched sources. In addition, a smaller proportion of material, depending on the natural gene flow dynamics of the focal species (but usually somewhere between 10 and 30% ), should be comprised of material from much further a field.

Whilst a composite provenancing approach may risk introducing some maladapted genes (a phenomena termed outbreeding depression), it crucially provides an opportunity for the migration of adapted genes and the evolution of new adaptive gene combinations through mixture of multiply sourced stocks, a key driver of evolution.

For restoration plantings, we need to be initiating plantings that will allow natural selection to act to produce a suitable and adaptively fit restored stand.

Since we first proposed these ideas (2008-2010), a number of restoration organisations have changed their seed sourcing strategy and starting taking into consideration genetic health issues and and introducing provenances that should allow plantings to be more resilient to climate changes in the future – which is a great outcome

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Staff, students and volunteers planting experimental designs into restoration projects on the Yorke Peninsula, SA

This post is an updated version of an article that was first published as:

Lowe AJ (2010) Composite provenancing of seed for restoration: progressing the ‘local is best’ paradigm for seed sourcing. In The State of Australia’s Birds 2009: Restoring Woodland Habitats for Birds. (Eds David Paton and James O’Conner). Supplement to Wingspan20(1) March. pp 16-17.

and incorporates ideas published in

Breed MF, Ottewell KM, Gardner MG, Marklund MHK, Dormontt EE, Lowe AJ (2015) Mating patterns and pollinator mobility are critical traits in forest fragmentation genetics. Heredity. Published online doi:10.1038/hdy.2013.48.

Breed MF, Stead M, Ottewell K, Gardner MG, Lowe AJ (2013) Which provenance and where? Seed sourcing strategies for revegetation in a changing environment. Conservation Genetics 14: 1–10.

Breed MF, Marklund MHK, Ottewell KM, Gardner MG, Harris JBC, Lowe AJ (2012) Pollen diversity matters: revealing the neglected effect of pollen diversity on fitness in fragmented landscapes. Molecular Ecology 21(24): 5955-5968. doi: 10.1111/mec.12056

Broadhurst LM, Lowe A, Coates DJ, Cunningham SA, McDonald M, Vesk PA, Yates C (2008) Seed supply for broadscale restoration: maximising evolutionary potential. Evolutionary Applications 1: 587-597.

Sgrò CM, Lowe AJ, Hoffmann AA (2011) Building evolutionary resilience for conserving biodiversity under climate change. Evolutionary Applications 4: 326–337. doi: 10.1111/j.1752-4571.2010.00157.x.

Other references

Bacles, C.F.E., Lowe, A.J. & Ennos, R.A. (2006) Seed dispersal across a fragmented landscape. Science, 311, 628.

Callaham, R.Z. (1964) Provenance research: Investigation of genetic diversity associated with geography. Unasylva, 18, 40–50.

Dick, C.W. (2001) Genetic rescue of remnant tropical trees by an alien pollinator. Proceedings of the Royal Society of London B, 268, 2391-96.

Ennos, R.A., Worrell, R. & Malcolm, D.C. (1998) The genetic management of native species in Scotland. Forestry, 71, 1-23.

Keller, M., Kollman, J. & Edwards, P.J. (2000) Genetic introgression from distant provenances reduces fitness in local weed populations. Journal of Applied Ecology, 37, 647-59.

Lowe, A.J., Unsworth, C., Gerber, S., Davies, S., Munro, R.C., Kelleher, C., King, A., Brewer, S., White, A. & Cottrell, J. (2006) The route, speed and mode of oak postglacial colonisation across the British Isles; Integrating molecular ecology, palaeoecology and modelling approaches. Botanical Journal of Scotland, 57, 59-82.

McKay, J.K., Bishop, J.G., Lin, J.Z., Richards, J.H., Sala, A. & Mitchell-Olds, T. (2001) Local adaptation across a climatic gradient despite small effective population size in a rare sapphire rockcress. Proceedings of the Royal Society of London, Series B: Biological Sciences, 268, 1715-21.

McKay, J.K., Christian, C.E., Harrison, S.P. & Rice, K.J. (2005) “How local is local?” – A review of practical and conceptual issues in the genetics of restoration. Restoration Ecology, 13, 432-40.

Moritz, C. (1999) Conservation units and translocations: strategies for conserving evolutionary processes. Hereditas, 130, 217-28.

Nathan, R. (2006) Long-distance dispersal in plants. Science, 313, 786-88.

O’Brien, E.K., Mazanec, R.A. & Krauss, S.L. (2007) Provenance variation of ecologically important traits of forest trees: implications for restoration. Journal of Applied Ecology, 1-11.

Wilkinson, D.M. (2001) Is local provenance important in habitat creation? Journal of Applied Ecology, 38, 1371-73.

Ward, M., Dick, C.W., Gribel, R., Lemes, M., Caron, H. & Lowe, A.J. (2005) To inbreed, or not to inbreed: A review of mating systems and pollen dispersal variance in neotropical trees. Heredity, 95, 246-54.

This article was also published on Prof Andy Lowe’s research group’s blog https://biodiversityrevolution.wordpress.com

DNA’s role in timber tracking

In this public lecture, Prof Andy Lowe speaks about the use of DNA to potentially solve conservation problems, particularly with regards to timber tracking.

Rainforests, the lungs of the planet, clean massive amounts of air and water.

The conversion of these forests into agricultural and urbanised systems is inherently linked to illegal logging.

“This is not a bleeding heart conservation talk. This is a talk about hope… about how technology can help save some of our planet’s resources”, says Prof Lowe.

TEDxAdelaide – DNA Barcoding for Biodiversity

Biodiversity and ecosystems provide us with clean air, water, and access to food.  However we don’t really know much about the basic building blocks of biodiversity.

How many species are there on earth? 10 million? What does this mean for humans? Over 250 years we’ve probably found and named approximately 1 million species, approx 10% of the biodiversity on earth.

At the same time the rate of intinction is increasing.

We’re going to need some help.

Following trend

Prof Andy Lowe officially launched Trend at the 2011 WOMAD Earth Station Festival.

TREND – Transects for Environmental Monitoring and Decision Making – is a componet of the Australian Transect Network, a long-term research and monitoring program dedicated to understanding how species and ecosystems change over space and time.