USING PALEOECOLOGY IN RESTORATION ECOLOGY
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VOLUME 30 ∙ NO 1 ∙ April 2022
MAGAZINE
USING PALEOECOLOGY IN
RESTORATION ECOLOGY
EDITORS
Lindsey Gillson, Cathy Whitlock, Peter Gell, Sabine Prader, Willy Tinner and Sarah Eggleston
SPECIAL SECTION
Socio-ecological approaches to conservation
EDITORS
Daniele Colombaroli and Evan Larson
2 ANNOUNCEMENTS
Calendar
News 4th PAGES Young Scientists Meeting
9-13 May 2022 – Online
Working group news
6th PAGES Open Science Meeting
Two new working groups launched at the beginning of 2022:
16-20 May 2022 – Online
PlioMioVAR (Pliocene and Miocene climate variability over glacial-interglacial timescales)
builds on key priorities identified by the community in the PAGES PlioVAR working group. PALSEA: Palaeo sea level and ice sheets for
pastglobalchanges.org/pliomiovar Earth's future
17-20 July – Singapore
Q-MARE (Disentangling climate and pre-industrial human impacts on marine
ecosystems) aims to produce new results on biodiversity loss under natural climate Climate Change, The Karst Record
variability and sustainability of both ecosystems and societies. 18-20 July – Innsbruck, Austria
pastglobalchanges.org/q-mare
IPICS 3rd Open Science Conference
Sir Nicholas Shackleton Medal For Outstanding Young Quaternary Scientists 2-7 October – Crans Montana, Switzerland
Award 2021
pastglobalchanges.org/calendar
Congratulations to Dr. Julie Loisel, co-leader of the PAGES C-PEAT working group, on
being named the 2021 recipient of the Sir Nicholas Shackleton Medal For Outstanding
Young Quaternary Scientists Award.
PAGES webinars
Featured publications
In December 2021, PAGES organized its 6th and 7th webinars. The PAGES-WCRP webinar ACME
introduced the new WCRP, its new science foci, and its elements, and highlighted Heikkilä M et al. published an invited review in
interfaces across which enhanced interactions and collaborations with PAGES can Anthropocene on predicting the future of coastal
flourish in the future. The PAGES-PMIP webinar aimed to help people find and use data marine ecosystems in the Arctic and the potential
from the PMIP simulations that could be useful for their own research, introduced which of palaeoenvironmental records.
climate models and periods have been used in PMIP, and dsicussed all things data pastglobalchanges.org/publications/128874
related.
DiverseK
youtube.com/playlist?list=PLSaCdvmD4wMIIbBmw5tuIJc5cpmoxYbER
Zhang Y et al. investigate vegetation response to
PAGES Early-Career Network (ECN) Holocene climate change in Central–East China,
A new community-driven ECR project (and product of the joint PAGES-INQUA early- and Hawthorne D et al. argue for the use of paleo-
career workshop 20-24 November in La Serena, Chile) on synthesizing human–climate– ecological records as a guide for fire manage-
environment interactions has been launched. The project is entitled "The whole is not the ment in Ireland.
sum of the parts: building a synthesis database of past human-environmental systems pastglobalchanges.org/taxonomy/term/219/
in the Global South (pSESYNTH)" and aims to test a key hypothesis, i.e. whether or not publications
cultural "stress" of ecosystems was widespread across the Global South during the
Floods Working Group
Holocene. Visit the website for more information and to sign up.
Wilhelm B et al. compile paleoflood records to
pases2020.com/index.php/psesynth-project
assess the uncertain impact climatic trends might
PAGES mobility fellowships have on flood frequency and magnitude in the
As part of an effort to actively promote the participation of early-career scientists and European Alps.
scientists from low- and middle-income countries in relevant working groups, workshops, pastglobalchanges.org/publications/128890
and other activities, PAGES launched two mobility fellowships in 2021. The first awardees
PALSEA
of the Inter-Africa Mobility Research Fellowship Program and the IAI International
PALSEA is proud of the list of 32 papers that have
Mobility Research Fellowship Program for Latin America and the Caribbean can be
been published within the past year. The full list
viewed on the PAGES website. The next deadline for all applications is 19 August. Check
of almost 200 PALSEA peer-reviewed articles,
our website for more information and updates: pastglobalchanges.org/support
PAGES Magazine articles, and special issues can
PAGES IPO staff update be found on the PALSEA publications website:
PAGES International Project Office welcomed Leigh Martens Winiger in November 2021. pastglobalchanges.org/taxonomy/term/116/
Leigh will be sharing the communications and project tasks with Chené van Rensburg. publications
The IPO also welcomes Dr. Basil Davis who will be joining the team for a period of six
VICS
months. Contact details for all IPO staff are available here: pastglobalchanges.org/about/
Plunkett G et al. challenge previous assumptions
structure/international-project-office
of a volcanic event, highlighting the need to
Deadline for new working groups, phase extensions, and workshop support revise the Common Era ice-core chronology and
The next deadline to propose a new PAGES working group, apply for a working group be formally accepted by the wider ice-core and
phase extension, submit an application for the data stewardship scholarship, or apply climate modeling communities.
for financial support for a workshop/meeting or conference is 19 September. All details: pastglobalchanges.org/publications/128860
pastglobalchanges.org/support
Past Global Changes Magazine: Changes to distribution
PAGES is happy to be able to offer free online access to Past Global Changes Magazine, Cover
as well as free hard copies to all interested parties. As an organization focused on climate
Rapidly changing ecological conditions challenge
and environment, we are also interested in keeping the number of printed copies to
forest management and restoration, raising
a minimum. We are, therefore, in the process of making changes to our distribution
questions about how reference conditions are
strategy. Any changes will be communicated, with ample warning, through our social
defined and where restoration is warranted,
media channels, website, and e-news. In the meantime, please take a moment to update
especially as we move towards climatic conditions
your profile on our People Database to ensure that the magazines are being sent to the
with no past analog. Two images from the subalpine
correct postal address: pastglobalchanges.org/people-database. We sincerely hope that
forest landscapes of the Rocky Mountain National
this does not cause any inconvenience and thank you for your understanding.
Park, CO, USA, illustrate widespread tree mortality
Upcoming issue of Past Global Changes Magazine between 2006 (left) and 2021 (right), as a result of
Our next magazine, guest edited by Matthew Chadwick, Amy Leventer, Anna Pienkowski, spruce bark beetles (foreground) and two unusual
and Heike Zimmermann from the C-SIDE and ACME working groups, focuses on sea wildfires, in 2012 and 2020 (mid- and background),
ice in the polar regions. Although preparations are well underway, if you would like to both of which burned in October, well after the
contribute, please contract our Science Officer: sarah.eggleston@pages.unibe.ch historical fire season in the region (photo credit:
P. Higuera).
PAGES MAGAZINE ∙ VOLUME 30 ∙ NO 1 ∙ April 2022 CC-BY
EDITORIAL: Using Paleoecology in Restoration Ecology 3
doi.org/10.22498/pages.30.1.3
Mainstreaming paleoecology
into ecosystem restoration
Lindsey Gillson1, C. Whitlock2, P. Gell3, S. Prader1 and W. Tinner4
2021 marked the beginning of the United environmental, biotic, and anthropogenic to document past changes in biodiversity
Nations Decade on restoration ecology. drivers can also cause shifts between alter- (e.g. see Wilmshurst and Wood p. 26).
Restoration of ecosystems is essential in nate stable states. This is especially likely at
• Communicating paleoecological findings
slowing biodiversity loss and associated ecotones (vegetational transitions), which
in an applied context, wherever possible,
erosion of ecosystem services. However, de- are sensitive to subtle changes in climate,
so that the information is accessible and
fining restoration goals in an uncertain and fire, and land use and therefore present par-
available to the restoration ecology com-
changing world raises fundamental ques- ticular challenges for restoration (Nanavati et
munity and beyond.
tions of what we are restoring and why. The al.p. 22; Giesecke et al. p. 24).
purpose of this special issue is to explore the • Greater integration of paleoecology with
contributions of paleoecology in addressing Why are we restoring? From static other disciplines and knowledge streams,
these questions and to encourage better "baselines" to dynamic processes including traditional ecological knowledge
integration of paleoecology into restoration In today's changing world, no-analog climate (see Gil-Romera et al. p. 20 and the special
ecology and conservation planning. conditions are increasingly likely in the section in this issue "Socio-ecological
coming decades, and a return to "natural" approaches to conservation" p. 33).
What are we restoring? conditions may be impossible or undesir-
• Showcasing the relevance of historical
The most obvious—and yet still under- able. As a result, there has been a shift in
perspectives in process-based thinking
utilized—use of paleoecological data in restoration ecology towards a broader range
and modeling efforts that guide adap-
restoration ecology is to provide reference of conservation objectives that considers the
tive management planning for emerging
conditions, especially in ecosystems that degree of past anthropogenic modification,
conditions and societal preferences (e.g.
have experienced significant anthropogenic as well as the desired ecosystem function
Morales-Molino and Schwörer p. 6).
degradation over periods of time that extend or condition (Chambers p. 16; Rull p. 18).
beyond living memory or historical records Considerations include which ecosystems • Validating dynamic modeling outcomes,
(e.g. Finlayson and Gell p. 10; Marcisz et al. will be most vulnerable to future climate for example, by comparing sedimentary
p. 12; Hapsari et al. p. 14). Paleoecological and land-use change and which should be proxy data with simulations of ecosystem
data sometimes reveal surprises regarding prioritised for restoration and conservation changes in response to climate change,
the extent and composition of vegetation actions (Adeleye et al. p. 28; Higuera et al. disturbance, and land use.
in the past, showing that current vegetation p. 30). Paleoecology can also guide efforts
• Encouraging managers and policy makers
is in fact far from natural, and confirming or to maintain critical ecological functions, such
to think on time scales longer than a few
rejecting the status of alien species (Nogué as pollination, by revealing unsuspected
decades so that paleoecological informa-
et al. p. 4; Wilmshurst and Wood p. 26). past interactions in species whose ranges
tion becomes routinely incorporated into
Although "naturalness" is a contested term, are currently disjunct (Wilmshurst and Wood
landscape conservation planning (e.g. the
areas with minimal or light human impact p. 26). The integration of paleoecology into
Ramsar Convention; see Finlayson and Gell
are, nevertheless, an important landscape an inclusive, process-based approach to
p. 10; Hapsari et al. p. 14; Chambers p. 16).
component in many regions (e.g. Nanavati et restoration ecology is illustrated in Figure 1.
al. p. 22; Morales-Molino and Schwörer p. 6; Note that as the future is uncertain, the The paleoecological community has a vital
Rull p. 18; Finsinger et al. p. 8). Restoration implementation approach needs to be challenge ahead: that of seamlessly integrat-
of desired cultural landscapes can also have adaptive. ing paleoecology and neo-ecology, thereby
benefits to both biodiversity and people enabling the mainstreaming of paleoecology
(see Rull p. 18). Conclusions and ways forward into restoration ecology and biodiversity
The papers in this issue demonstrate a huge conservation.
Even without significant human impact, most and largely untapped synergy between the
landscapes are dynamic and respond to disciplines of paleoecology and restora- AFFILIATIONS
multiple interacting environmental driv- tion ecology. Ensuring that this potential is 1
Plant Conservation Unit, Department of Biological
ers, including changes in climate, distur- realized will require a concerted effort by the Sciences, University of Cape Town, South Africa
bance, land use, and biotic interactions. paleoecological community in seven main 2
Department of Earth Sciences, University of Montana,
Understanding the long-term importance areas: Bozeman, USA
of fire and herbivory, for example, is an 3
School of Science, Psychology and Sport, Federation
• Better calibration of paleoecological datas- University Australia, Ballarat, Australia
important scientific contribution from paleo-
ets to increase their usefulness as reference 4
Institute of Plant Sciences and Oeschger Centre
ecology, particularly as it relates to climate
frameworks for conservation planning. for Climate Change Research, University of Bern,
extremes, land abandonment, and rewild-
Switzerland
ing (Higuera et al. p. 30; Morales-Molino • Wider incorporation of new techniques,
and Schwörer p. 6). Interactions among such as ancient DNA/sedimentary DNA, CONTACT
Lindsey Gillson: lindsey.gillson@uct.ac.za
Stakeholder consultation, integration
of diverse knowledge streams
Modeling of
Identify landscape change Decide on Implement
Describe processes that appropriate
Paleo- adaptive
historical drove past restoration
ecological Calibration management
range of change targets
data variability
Neo-ecological Scenario planning
understanding of
process and function
Figure 1: A suggested framework by which paleoecology could be integrated with other disciplines and knowledge streams in a process-based approach to restoration
ecology that includes science, modeling, stakeholder consultation and adaptive management.
PAGES MAGAZINE ∙ VOLUME 30 ∙ NO 1 ∙ April 2022 CC-BY
4 SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology
doi.org/10.22498/pages.30.1.4
Multiple baselines for restoration ecology
Sandra Nogué1,2, L. de Nascimento3, W.D. Gosling4, N.J.D. Loughlin5, E. Montoya6 and J.M. Wilmshurst7,8
Recent work within restoration ecology has highlighted the importance of incorporating ecological history. Using three
complementary examples from New Zealand offshore islands, the tropical Andes, and the Canary Islands, we discuss
how restoration goals may be addressed using multiple baselines, or reference conditions, from long-term data.
The idea of using long-term ecological data Paleoecological records are recognized only was Metrosideros unexpectedly uncom-
to measure changes in biodiversity and to in New Zealand as an additional tool to mon in the past, but the pre-human baseline
improve the effectiveness of conservation document natural pre-human vegetation has no current analog on any northern New
strategies has been widely discussed (Willis baselines and to help guide restoration Zealand islands. This, and other paleoeco-
et al. 2010; Nogué et al. 2017). Importantly, plans (Wilmshurst et al. this issue). Long-term logical records from the region, demonstrate
the use of baselines, or reference conditions, records have also been combined with local the power of the past to help inform future
has already been recognized in environ- Māori (New Zealand's indigenous Polynesian directions for conservation management.
mental policy such as in the conceptual population) knowledge, or mātauranga, to
framework for the 2019 Intergovernmental provide cultural vegetation baselines and to (2) Examples from the tropical Andes
Science-Policy Platform on Biodiversity and help inform biocultural approaches to island
Ecosystem Services (IPBES) global assess- conservation (Lyver et al. 2015). For example, The Andean flank region has particularly
ment report, and the United Nation decade pollen and charcoal records showed how caught the attention of researchers and
on ecosystem restoration (2021–2030). It is, some forested ecosystems were cleared for policymakers due to its ecological value,
therefore, clear that there is now an urgent Māori gardens, and local Māori communities and both its historical and current anthro-
need to organize and standardize baselines now desire some forest to be restored to pogenic pressures (Cuesta et al. 2019).
if we want to implement successful restora- states that would provide a range of future Paleoecological studies carried out in the
tion actions taking into account the complex- benefits to their cultural, social, economic, tropical Andes have focused on using past
ity of managing both ecological and cultural and ecological needs (Lyver et al. 2015). environmental information to anticipate
systems (Jackson and Hobbs 2009; Nogué future scenarios of global change, includ-
et al. 2021). We highlight three case studies Sometimes paleoecological records can ing: (1) observing the synchronicity between
to show how restoration goals may be ad- reveal surprises that overturn current environmental change and societal restruc-
dressed using paleoecologically informed ecological understanding. For example, the turing and adaptation in pre-Columbian
baselines. Poor Knights Islands in northeastern New populations (Gosling and Williams 2013);
Zealand are currently covered in a tall forest (2) pinpointing potential microrefugia loca-
(1) Vegetation baselines for New Zealand of native angiosperm trees dominated by tions based on the past dynamics of the
offshore islands Metrosideros. This vegetation composi- Andean flag taxon Polylepis sp. (Valencia
tion has long been considered to be in a et al. 2016); and (3) highlighting shifted
New Zealand's offshore and outlying islands natural baseline state and is used to inform historical baselines such as those observed
are important foci for biodiversity protec- replanting of degraded islands in the region. in the 19th century in locations with large
tion and conservation, with many supporting However, a 2000 year record of pollen, pre-Columbian anthropogenic pressure that
species that have been extirpated from the charcoal and ancient plant DNA from a soil suffered depopulation following European
main islands (Bellingham et al. 2010). Most core on the island (Fig. 1) tells a different arrival (Loughlin et al. 2018).
islands have been modified since initial story (Wilmshurst et al. 2014). The forest was
human settlement began ca. 780 years ago, cleared by fire in the 13th century and gar- For example, fossil pollen showed a succes-
mainly by forest clearance and introduced dened by Māori for ca. 550 years, followed sion of Andean forest driven by changes in
mammalian pests (particularly rodents, cats, by 180 years of forest succession after they land-use. This forest succession was divided
goats and pigs). Conservation efforts in the ceased living there. The pre-human vegeta- into five different vegetation baselines
last 50 years have focused on eradicating tion was completely different to today's (Loughlin et al. 2018): pre-European (pre-CE
alien species and replanting and restoring forest, consisting of a diverse, conifer- 1588 indigenous occupation), successional
the "natural" vegetation. However, baselines dominated forest (e.g. Dacrydium cupres- (CE 1588–1718 European arrival/re-coloni-
have usually been informed by historic de- sinum and Prumnopitys ferruginea) with an zation), mature (CE 1718–1819 diminished
scriptions of vegetation and/or the composi- understory palm (Rhopalostylis sapida) and population), deforestation (post CE 1819,
tion of nearby forested locations. several other locally extinct tree taxa. Not re-colonization), and modern (industrial
Key forest taxa Disturbed taxa
m
ea
inu
m
gin
a
tu
Ph n pu apid
s
a
es
ae len
u s ru
cr cla ys tar
Ne di u er
s
pr
pe m m
ss
An race scu
ali
Dayllo opit s to
f
yr is cu
Cy idiu rmu
os
nt
yli
s
e
er
M steg m
s rie
Po ero
d
Po lost
et e
er e
al
Ty eae
sid
um ar
M lin
nu o
Pt osp
rd e
co
oc
a
Co in
Pr oc
Pi pha
y
y
ro
op
ac
ar
s
th
pt
d
Ch
Rh
Le
2000 0
Novel ecosystem
10
20
30
Depth (cm)
Yr CE
1500 40
50
Maori gardens
60
1000 70
Baseline forest
500 80
0 20 40 60 0 20 40 0 0 0 0 20 0 0 0 20 0 20 40 60 80 0 20 0 20 0 20 0 20 40 0 20 0 0
Figure 1: Example from Tawhiti Rahi Island of the Poor Knights Islands (Wilmshurst et al. 2014). Pollen data shows that the current vegetation composition is completely
different from ancient ecosystems (photo credit: J.M. Wilmshurst).
PAGES MAGAZINE ∙ VOLUME 30 ∙ NO 1 ∙ April 2022 CC-BY
SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology 5
1
DCA2
0 -1
-1 0 1
DCA1
1 2 3
Ancient Pre-European Successional
4 5 6
Mature Deforestation Modern
Figure 2: Detrended correspondence analysis (DCA) of pollen data from Andean montane forest grouped into time bins. Red arrow indicates an increasing signal of human
impact. Replotted from Loughlin et al. (2018) (photo credit: N.J.D. Loughlin).
agriculture). These results were compared these new insights from the pollen record, (NE/L501888/1), and a NERC fellowship to E.M. (NE/
to a close site indicative of pre-human ar- Juniperus turbinata was considered a rare J018562/1).
rival vegetation (42 cal kyr BP; ancient), and tree on the island (del Arco et al. 2006). This AFFILIATIONS
showed the closest similarity with the post- mismatch between data sources highlights 1
CREAF, Centre de Recerca Ecològica i Aplicacions
abandoned mature state (Fig. 2). These new the utility of combining paleoecological data Forestals, Bellaterra (Cerdanyola del Vallès),
insights from sedimentary cores spanning into restoration planning, and improving Catalonia, Spain
the past three to four centuries show the understanding around past composition and
2
School of Geography and Environmental Science,
potential to characterize meaningful restora- occurrence of plant communities. University of Southampton, UK
3
Island Ecology and Biogeography Group, Instituto
tion targets and reference ecosystems from
Universitario de Enfermedades Tropicales y Salud
paleoecological data (see Rull, this issue). In Teno, on the island of Tenerife (European Pública de Canarias (IUETSPC), Universidad de La
Union LIFE Habitat project), the reference Laguna, Canary Islands, Spain
(3) The thermophilous forest of the Canary condition was obtained by a combination 4
Department of Ecosystem and Landscape Dynamics,
Islands of sources, including inventories of locally Institute for Biodiversity and Ecosystem Dynamics,
remaining Juniperus turbinata trees and University of Amsterdam, The Netherlands
The Canarian thermophilous woodland is patches of Juniper woodlands remaining in 5
Geography & Environmental Sciences, Northumbria
among the most threatened ecosystems in the archipelago (Tenerife and La Gomera), University, Newcastle Upon Tyne, UK
the Canary Islands (del Arco et al. 2010). The potential vegetation maps, toponymy (e.g.
6
Laboratory of Paleoecology, Geosciences Barcelona
(CSIC), Barcelona, Spain
remnants of these woodlands are currently place name or geographic name), and his- 7
Long-term Ecology Laboratory, Manaaki Whenua-
occupying less than 10% of their original torical and recent (elderly locals) accounts, Landcare Research, New Zealand
area and are undergoing several restora- to confirm past occurrence of the woodlands 8
School of Environment, University of Auckland, New
tion actions. Describing baselines for these (Fernández-Palacios et al. 2008). Ten years Zealand
woodlands have proved challenging and is after plantation, populations of J. turbinata
limited to the available ecological informa- are showing positive growth trends, with CONTACT
Sandra Nogué: s.nogue@creaf.uab.cat
tion from the few woodlands remaining on eight tree and shrub species surviving, grow-
the islands. ing, and some even showing signs of repro- REFERENCES
duction (flowers and fruits) (Rota et al. 2021). Bellingham PJ (2010) N Z J Ecol 34: 115-136
On the island of Gran Canaria, there have Bush MB et al. (2014) Restor Ecol 22: 296-298
been several restoration programs mostly Conclusions
Cárdenes JL (1998) Medio Ambiente Canarias 11: 15-16
focused on laurel forest remnants, since With these three examples, covering
only 1% of its original distribution remains ecosystems varying from high-mountains Cuesta F et al. (2019) Reg Environ 19: 1623-1642
on the island today. One program included to islands, and from both hemispheres, we del Arco MJ et al. (Ed) (2006) Mapa de Vegetación de
restoring the Laguna de Valleseco as part show the importance of incorporating pa- Canarias. GRAFCAN, 552 pp
of the LIFE Laurisilva XXI project, with a key leoecological knowledge and other sources del Arco MJ et al. (2010) Biodivers Conserv 19: 3089-3140
objective devoted to education (Cárdenes of long-term data in restoration programs. de Nascimento L et al. (2016) Holocene 26: 113-125
1998). When this project was implemented, There are numerous examples of paleo- Fernández-Palacios JM et al. (2008) Los bosques
the pre-human baseline for the site was ecological research that have highlighted a termófilos de Canarias (Proyecto LIFE04/NAT/
thought to be laurel forest with the pres- priori misconceptions on the definition of the ES/000064). Santa Cruz de Tenerife: Cabildo
ence of e.g. Ilex canariensis, Erica arborea, natural vegetation (Bush et al. 2014), and the Insular de Tenerife
and Morella faya agreeing with the potential ability of past environmental change data to Gosling WD, Williams JJ (2013) Holocene 23: 1619-1624
vegetation maps that predicted its presence characterize landscapes that are different
Jackson ST, Hobbs RJ (2009) Science 325: 567-569
in the area (del Arco et al. 2006). However, to those of today (Rull et al. 2017). Paleo-
Loughlin NJD et al. (2018) Nat Ecol Evol 2: 1233-1236
a paleoecological record carried out at the informed baselines may provide a useful
same site suggested a wider distribution of perspective on the variability of ancient sys- Lyver POB et al. (2015) Hum Ecol 43: 681-695
the thermophilous forest in the past, includ- tems, the magnitude of biodiversity change, Nogué S et al. (2021) Science 372: 488-491
ing this northern area. Fossil pollen records novel ecosystems, and responses to succes- Nogué S et al. (2017) Nat Ecol Evol 1: 0181
showed the unexpected presence of ther- sive waves of cultural transformation. Rota F et al. (2021) Scientia Insularum 4: 27-44
mophilous species such as Juniperus and the
Rull V et al. (2017) PAGES Mag 25: 82-83
date palm (Phoenix canariensis) until about ACKNOWLEDGEMENTS
2300 years ago when there was an increase Valencia BG et al. (2016) New Phytol 212: 510-522
This work was supported by the Spanish Ministry
in fires, and grasses and shrubs spread over of Science and Innovation (CGL 2009-10939), the Willis KJ et al. (2010) Trends Ecol Evol 25: 583-591
the area (de Nascimento et al. 2016). Before Open University through a scholarship to N.J.D.L. Wilmshurst JM et al. (2014) Conserv Biol 28: 202-212
CC-BY PAGES MAGAZINE ∙ VOLUME 30 ∙ NO 1 ∙ April 2022
6 SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology
doi.org/10.22498/pages.30.1.6
Paleoecology-guided ecosystem management
and restoration in the Western Mediterranean
César Morales-Molino and Christoph Schwörer
Drawing on several case studies from the Iberian Peninsula, we show how specifically designed paleoecological
research can be a useful tool to guide ecosystem management, conservation, and restoration.
The Mediterranean region is well known for regime will, in turn, also promote seedling knowledge about the carrying capacity of
its outstanding diversity of species and eco- recruitment. these ecosystems, i.e. the herbivore densi-
systems. This natural heritage is, neverthe- ties that the ecosystem can tolerate without
less, threatened not only by ongoing climatic Unprecedented herbivore densities risking its functionality.
change, but also by legacies of multi-millen- and the fate of Mediterranean mires
nial land use and shifts in land-use patterns, Another worrying aspect of ongoing land In the Cabañeros National Park (central-
which can significantly alter natural distur- abandonment, in combination with the lo- southern Spain), current densities of wild
bance regimes. This raises questions for cal extirpation of natural predators, is the ungulates (e.g. red deer, wild boar) are so
management and restoration of ecosystems dramatic increase in the densities of wild un- high that mires are regularly damaged, and
that can be informed by long-term data from gulates that prevents the recruitment of pal- tree regeneration is seriously affected. We
paleoecology. Here, we discuss three ex- atable woody species and causes potentially conducted paleoecological research on
amples from the Iberian Peninsula that relate damaging disturbance when large herds two peat sequences to investigate the past
to fire management, herbivore management, visit wetlands (e.g. mires, springs, ponds) impact of herbivore densities (wild ungulates
and the conservation of cultural landscapes. during the dry Mediterranean summers. and livestock), inferred from dung fungal
Managers of protected areas need scientific spores (Baker et al. 2016), and land use on
Changing fire regimes and their
impact on Pinus nigra forests (a) Tubilla del Lago (900 m asl)
Depopulation of rural areas and abandon-
Fire episodes
ment of traditional farming practices are
(small-moderate
currently leading to increased woodland en- vs large)
croachment, and subsequent accumulation 100 10
of dead biomass (Keeley et al. 2012). Under Cerealia
Cerealia and dung fungi (%)
90 9
particularly favorable conditions for fire 80 8
spread and the presence of (usually anthro- Pinus
70 7
pogenic) ignition sources, these landscapes
Pinus (%)
60 6
offer the perfect setting for catastrophic
50 5
fires. Concerned by this relevant and increas-
ingly pressing issue, ecosystem managers 40 4
often try to adapt forest management strate- 30 3
gies to prevent these large and severe fires, 20 Dung fungi 2
or at least limit their spread. 10 1
0 0
In the Northern Iberian Plateau (central- 7000 6000 5000 4000 3000 2000 1000 0
northern Spain), we investigated the causes Age (cal yr BP)
of the regional demise of Pinus nigra forests (b) Arroyo de las Cárcavas (1300 m asl)
during historical times using a multi-proxy
stomata (%)
approach including pollen, conifer stomata, 20
dung fungal spores, and charcoal particles,
Pinus
alongside peak detection analysis (Morales-
Molino et al. 2017a). The results show that
pine forests were the dominant vegetation in
100
the region for most of the Holocene, under
a mixed fire regime consisting of frequent
low-severity (ground) fires and rare high-se- 80
verity (crown) fires (Fig. 1). Consistent with its
Pinus pollen (%)
life-history traits (Tapias et al. 2004), P. nigra 60
was able to resist ground fires but, unexpect-
edly, stands could also recover after single
crown fires despite lacking specific adapta- 40
tions (e.g. serotinous cones). However, when
crown fires became very frequent with the 20
intensification of arable and pastoral farming
during the Middle Ages (1200–1000 yr cal
BP), pine forests rapidly declined and even
disappeared regionally (Fig. 1a). 2400 2000 1600 1200 800 400 0
Age (cal yr BP)
The take-home message for forest manag-
ers who want to preserve the species-rich Figure 1: (A) Paleoecological record from Tubilla del Lago (central-northern Spain). Top: Fire episodes as
Pinus nigra forests currently thriving in the reconstructed using peak detection analysis (Higuera et al. 2009) applied to the high-resolution macroscopic
circum-Mediterranean mountains is that fuel charcoal series, distinguishing between small-moderate ("surface fires") and large ("crown fires") peaks. Bottom:
Abundances of Pinus pollen and the main local indicators of farming activities (Cerealia type, dung fungal
loads need to be managed using prescribed
spores). Red triangles denote the occurrence of crown fires. Modified from Morales-Molino et al. (2017a);
ground fires, in order to prevent high-
(B) Pollen and stomata evidence of the dominance of Pinus in the Sierra de Guadarrama for the past > 2000 yr.
severity crown fires. This low-severity fire Modified from Morales-Molino et al. (2017b).
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SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology 7
Las Viñuelas (750 m asl) El Brezoso (730 m asl)
(a)
Dung fungal spores
25 100
(102 # cm-2 yr-1)
20 80
15 60
10 40
5 20
0 0
(b) Cerealia-t.
4 Plantago lanceolata-t.
Anthropogenic
12
indicators (%)
Plantago coronopus-t.
Rumex acetosa/acetosella-t.
pollen
8
2
4
0 0
(c)
40 40
Betula
(%)
20 20
0 0
(d)
Sphagnum
20 200
10 100
(%)
0 0
4000 3500 3000 2500 2000 1500 1000 500 0 4000 3500 3000 2500 2000 1500 1000 500 0
Age (cal yr BP) Age (cal yr BP)
Figure 2: Paleoecological sequences from the Cabañeros National Park (central-southern Spain). Abundances of (A) dung fungal spores, a proxy for past herbivore density
(Baker et al. 2016); (B) anthropogenic pollen indicators, directly or indirectly related to farming activities and disturbance; (C) Betula pollen; (D) Sphagnum spores, which are
related to the extent and integrity of the mires. Modified from Morales-Molino et al. (2019).
the mires of this protected area (Morales- perspective of paleoecology on vegetation For instance, dynamic vegetation models
Molino et al. 2019). The pollen and dung dynamics, in particular in response to human allow us to disentangle the past roles of
fungal spore data show that locally growing impacts, allows a largely refined discussion climate, disturbance, and human activities in
Betula stands, as well as Sphagnum mats, de- of this topic (e.g. Carrión and Fernández driving vegetation changes, improving pre-
clined and even went extinct when pastoral 2009). dictions of future vegetation dynamics under
farming increased during the Middle Ages different scenarios of climate change and
(1000–800 yr cal BP; Fig. 2). The influxes In the Valsaín forests of the Sierra de land use (e.g. Henne et al. 2015; Schwörer et
of dung fungal spores suggest that the Guadarrama National Park, in the Iberian al. 2014). Additionally, population genetic
extremely high current herbivore densities Central Range, the potential natural vegeta- analyses on ancient DNA preserved in plant
are unprecedented in the context of the past tion would consist of Quercus pyrenaica macrofossils may provide unique informa-
4000 years. Therefore, herbivores pose a forests, whereas pine forests are thought tion on which variant of a given tree species
severe threat to extant mires in the region, to have been favored by humans (Morales- would be best suited to revive a popula-
including those where relict birch stands still Molino et al. 2017b). We analyzed several tion that became locally extinct in the past
survive. We strongly recommend fencing mires using a multi-proxy approach (pol- (Schmid et al. 2017).
the mires to prevent further destruction by len, conifer stomata, plant macrofossils) to
ungulates, as well as controlling the popula- investigate whether Pinus sylvestris forests AFFILIATION
tions of these herbivores, preferably by the occur naturally at relatively low elevation in Institute of Plant Sciences and Oeschger Centre
re-introduction of natural predators such as these mountains. The high pollen percent- for Climate Change Research, University of Bern,
wolf or Iberian lynx, which went regionally ages along with the finds of Pinus stomata Switzerland
extinct just a few decades ago. and macrofossils demonstrate that Scots
CONTACT
pine has dominated forests as low as 1300 m César Morales-Molino: cesar.morales@ips.unibe.ch;
What is "natural" in the asl for at least the past 2500 years (Fig. 1b). cesarmoralesdelmolino@gmail.com
Mediterranean region? Paleoecological evidence therefore sup-
The millennial history of farming and forest ports the naturalness of pine forests and REFERENCES
use in the Mediterranean region makes it refutes the need to favor Quercus pyrenaica Baker AG et al. (2016) Methods Ecol Evol 7: 1273-1281
hard to assess the naturalness of certain eco- in forest management. Carrión JS, Fernández S (2009) J Biogeog 36: 2202-2203
systems often considered as purely anthro- Chiarucci A et al. (2010) J Veg Sci 21: 1172-1178
pogenic based on a shorter-term perspec- Conclusions and outlook
Farris E et al. (2010) J Biogeog 37: 2211-2213
tive. Precise knowledge about the "natural" The three case studies presented above
Henne PD et al. (2015) Front Ecol Environ 13: 356-362
composition and structure of vegetation is illustrate how paleoecological data provide
of paramount importance if the goal is to relevant information to guide the conser- Higuera PE et al. (2009) Ecol Monogr 79: 201-219
restore ecosystems to their "original" state, vation and restoration of Mediterranean Keeley J et al. (2012) Fire in Mediterranean Ecosystems:
preceding the onset of heavy human impact. ecosystems. The first two examples show Ecology, Evolution and Management. Cambridge
how paleoecological records can assist in University Press, 515 pp
The question of what the natural vegetation restoring fire regimes and herbivore densi- Loidi J, Fernández-González F (2012) J Veg Sci 23:
in an area would be remains crucial in many ties that maintain and recover vegetation. 596-604
Mediterranean areas that were intensively The third example shows how the long-term Morales-Molino C et al. (2017a) J Ecol 105: 634-646
disturbed by land use in the past. The perspective provided by paleoecology, par- Morales-Molino C et al. (2017b) Glob Planet Change 152:
"potential natural vegetation" concept, i.e. ticularly with respect to past human impacts 64-75
mature vegetation in the absence of human on vegetation dynamics, can help resolve Morales-Molino C et al. (2019) Ecology 100: e02833
impact, has been widely used during the some of the controversies raised by the
Perea R, Gil L (2014) For Ecol Manag 312: 47-54
past few decades in this context, despite be- "potential natural vegetation" concept (e.g.
ing subject to debate and controversy (e.g. Carrión and Fernández 2009). However, we Schmid S et al. (2017) Methods Ecol Evol 8: 1374-1388
Carrión and Fernández 2009; Chiarucci et al. acknowledge the need for refinements and Schwörer C et al. (2014) Glob Chang Biol 20: 1512-1526
2010; Farris et al. 2010; Loidi and Fernández- novel techniques for a broader use of these Tapias R et al. (2004) Plant Ecol 171: 53-68
González 2012). The long-term empirical data in a global change scenario.
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8 SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology
doi.org/10.22498/pages.30.1.8
The value of long-term history of
small and fragmented old-growth
forests for restoration ecology
Walter Finsinger1, E. Cagliero1,2, D. Morresi3, L. Paradis1, M. Čurović4, M. Garbarino3, N. Marchi2, F. Meloni3,
V. Spalević5, E. Lingua2 and R. Motta3
The long-term history of small and fragmented old-growth forests can provide insights into the legacies of past
environmental changes and land-use history in the surrounding landscapes, which can support nature protection and
restoration ecology measures.
The value of old-growth forests and remote sensing (Barredo et al. 2021). shattered due to major human imprints on
Primary and old-growth forests are of great However, these methods cannot provide forest ecosystems over past millennia (Birks
value for sustainable forest management and information on the longer-term history of an and Tinner 2016). However, primary and
restoration. By virtue of their structural and area. Paleoecology, instead, is sometimes old-growth forests are particularly abundant
compositional complexity, they are highly the best, and only, tool for documenting in some regions, such as the Dinaric Alps,
biodiverse when compared with managed the continuity of forest ecosystems and the possibly due to early protection of forests
forests in the same ecological region, as they legacies of land-use history, climate change, and lower historical human pressure com-
offer a variety of microhabitats such as large and disturbances (such as fire) on present- pared to other mountain ranges in Europe
pieces of coarse, woody debris, providing day forest composition. This information (Sabatini et al. 2018). Indeed, this mountain
shelter to a range of taxa. These naturally re- is critical for clarifying conservation and region is characterized by rugged terrain
generated forests of native trees are thought restoration objectives because mosaic land- and land with low agricultural productivity
to have developed dynamically for a long scapes are often the result of legacy effects (Kaplan et al. 2009). Nonetheless, detailed
period of time without large stand-replacing arising from complex interactions between records documenting long-term vegetation
disturbances, and show no indication of natural and human disturbances (Whitlock dynamics, in conjunction with environmental
human activities (Barredo et al. 2021). They et al. 2018). In this context, stand-scale changes, are lacking for the montane zone in
offer unique opportunities to characterize paleoecology can be particularly valuable this region (Finsinger et al. 2017).
the effects of natural disturbances and the as it allows us to address the history of small
structural heterogeneity emerging from and fragmented ecosystems (Bradshaw and Legacies of past land uses at an old-
natural forest dynamics. This is important Zackrisson 1990; Foster et al. 1996). growth forest's fragment edge
knowledge to develop close-to-nature forest Cagliero et al. (2021) recently presented
management practices aimed at emulating Old-growth forests remnants stand-scale paleoecological records, an as-
natural processes and features in second- in the Balkans sessment of contemporary forest structure,
growth forests (Schütz et al. 2016). The causes of the current fragmented dis- and dendrochronological data from the
tribution of old-growth forests in Europe is edge of the Biogradska Gora old-growth
In Europe, primary and old-growth forests a long-standing question in ecology. They forest (Dinaric Alps, Montenegro), one of the
are very rare, generally small, fragmented, are arguably remnants of formerly larger largest in Europe. It provides new insights
and less abundant (< 3% of the total forest extents of "primeval forests", "virgin forests", into the long-term dynamics of these frag-
area) than on other continents (Sabatini et al. "climax forests", or "Urwald" that have been mented ecosystems. Like other old-growth
2018). Currently, these forests are embed-
ded in landscape mosaics bearing variously
800
managed patches that are sometimes strik- Forest plots data c
600
(m³/ha)
Coarse
woody
ingly different in species composition and
b
debris
400
structure. Thus, the small and fragmented
200
ecosystems are threatened along fragment a
0
edges by land-use activities (e.g. logging) Beech forest Fir-beech- Fir-beech
and anthropogenic disturbances (e.g. fire ig- surrounding spruce old-growth
nitions) that may initiate long-term changes the old-growth old-growth forest plots
to the structure of the remaining fragments, forest forest plots
thereby hindering the development or the
continuity of the old-growth forest stage.
Old-growth forests are typically late-
successional forests that contain structures
and species that are markedly different from Conifers
forests of earlier stages. Their distinguishing
Broadleaved trees
features include high amounts of dead-
wood, presence of old trees approaching Forest-canopy gaps
their natural longevity (which is often much Grasslands, meadows
higher than the management rotation cycle
Bare ground
for a given tree species), and a patchwork N
of heterogeneously aged stands arising Water
through small-scale gap dynamics (Barredo Old-growth forest
et al. 2021). 0 1 2 3 km
Forest hollow
The current old-growthness is generally
Figure 1: Distribution of land-cover types in the Biogradska Gora valley (Dinaric Alps, Montenegro). The boxplot
assessed using field-based methods, such
shows the amount of coarse woody debris inside and outside of the old-growth forest (modified from Cagliero
as dendroecology and forest surveys,
et al. 2021).
PAGES MAGAZINE ∙ VOLUME 30 ∙ NO 1 ∙ April 2022 CC-BY
SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology 9
Medieval Climate Paleoecology, in conjunction with structural
Reserve &
Anomaly Black Death Park and dendrochronological research, can
unfold the history of Europe's primary and
Little Ice Age old-growth forests. Thereby, their responses
60 to past environmental changes, as well as
legacy effects of past land use and of distur-
Charcoal
(influx)
40
bances in surrounding landscapes, can be
assessed. This may be important as strate-
20
gies for the preservation and restoration of
old-growth forests should acknowledge past
0
100
Fagus stomata
Macrofossils
(concentr.) (concentr. x 10³) (concentr.)
environmental changes, including land-use
Pollen (%)
history, and anticipate future environmental
50
Acer, Ulmus, Fraxinus excelsior
Fagus sylvatica (beech) changes.
50
20
Although primary and old-growth forests
0
250 0
are generally included in protected areas
Dung Tilletia (Sabatini et al. 2018), they may be vulnerable
Pollen (%)
12
fungi
to climate change and associated changing
Spores
Primary anthropogenic pollen
8
disturbance regimes (wind, pathogens, or
fire; Seidl et al. 2017). For instance, several of
10
4
the smaller old-growth forests that bear fire-
0
sensitive species such as Abies alba may be
20
stomata
Macrofossils
Pollen (%)
at risk if fire-frequency becomes excessive.
15
Picea abies (spruce) In this context, identifying and protecting
primary and old-growth areas and their buf-
10
Abies alba (fir)
fer zones, as well as protecting and restor-
5
ing secondary forests that may represent
0
0
future primary and old-growth ecosystems
Trees and Shrubs (Barredo et al. 2021; EU's Biodiversity
Pollen (%)
80
Strategy for 2030: ec.europa.eu/environment/
strategy/biodiversity-strategy-2030_en) could
40
be of paramount importance to promote
¹⁴C datings
native forests. Such actions may likely in-
0
1100 1300 1500 1700 1900 crease ecosystem resilience to future climate
CE years change and be helpful to anticipate environ-
mental changes (Henne et al. 2015).
Figure 2: Local vegetation and fire-disturbance dynamics at the current edge of Biogradska Gora's old-growth
forest as reconstructed with the sediments from a small forest hollow. The charcoal-influx graph includes the
long-term trend of charcoal accumulation (grey line) and identified fire episodes (crosses; red crosses: higher-
AFFILIATIONS
1
ISEM, Univ Montpellier, CNRS, EPHE, IRD, France
severity catchment fires). Pollen and spores (filled areas), stomata (full circles), and plant macrofossils (black bars)
2
Department of Land, Environment, Agriculture and
illustrate the vegetation dynamics and land-use history (primary anthropogenic pollen and Tilletia spores: cereal
Forestry, University of Padova, Legnaro, Italy
crop cultivation; cattle herding: dung-fungi spores). Full black circles (bottom) show the location of radiocarbon
3
Department of Agricultural, Forest and Food
dates (modified from Cagliero et al. 2021).
Sciences, University of Torino, Grugliasco, Italy
4
Biotechnical Faculty, University of Montenegro,
forests in the montane zone of the Balkans, After intensive local land use ceased (in the Podgorica, Montenegro
Biogradska Gora's old-growth forest is domi- mid-14th century, approximately at the time 5
Geography Department, University of Montenegro,
nated by fir (Abies alba) and beech (Fagus of the Black Death pandemic) and during Nikšić, Montenegro
sylvatica) with sparse spruce (Picea abies) the cooler Little Ice Age, beech-dominated CONTACT
(Motta et al. 2015). However, unlike many stands developed in the area surrounding Walter Finsinger: walter.finsinger@umontpellier.fr
other old-growth forests, this one is sur- the old-growth (Fig. 2). The legacy of past
rounded by grasslands and meadows, and land use is still visible as the almost pure REFERENCES
by almost pure beech stands. These stands beech stands show less old-growthness Barredo JI et al. (2021) Mapping and assessment of
are characterized by small, mostly multi- than other European beech-dominated primary and old-growth forests in Europe.
stemmed trees, the amount of coarse woody old-growth forests. Conversely, the formal Publications Office of the European Union, 42 pp
debris is negligible (Fig. 1), and charcoal protection of the Biogradska Gora forest Birks HJB and Tinner W (2016) In: San-Miguel-Ayanz J et
kilns are present. By contrast, the fir-beech- as a royal hunting reserve and as a national al. (Eds) European Atlas of Forest Tree Species.
spruce dominated old-growth forest has a park since the late 19th century prevented Publications Office of the European Union,
e010c45+
mixed and multilayered structure shaped intensive land use, and has strongly reduced
by gaps of different sizes, a large amount of biomass burned in recent times, which has Bradshaw RHW, Zackrisson O (1990) J Veg Sci 1: 519-528
coarse woody debris, and very large and old allowed for the persistence of the beech Cagliero E et al. (2021) Veg Hist Archaeobot, doi:10.1007/
trees (> 500 years old), indicating that this stands in the buffer zone. This protected s00334-021-00862-x
part of the forest developed dynamically for zone may offer a habitat for adaptation to Finsinger W et al. (2017) Quat Sci Rev 167: 63-77
a long period of time without human and future environmental changes, such as the Foster DR et al. (1996) Trends Ecol Evol 11: 419-424
natural stand-replacing disturbances. expansion of the fir old-growth, as fir has
Fröhlich J (1930) Centr Gesamte Forstwesen 56: 49-68
more potential than spruce and beech under
Henne PD et al. (2015) Front Ecol Environ 13: 356-362
The well-dated pollen, spore, stomata, warmer and drier conditions (Vitasse et al.
plant-macrofossil, and charcoal records from 2019). Kaplan JO et al. (2009) Quat Sci Rev 28: 3016-3034
a small forest hollow at the current edge Motta R et al. (2015) Plant Biosyst 149: 966-975
of the old-growth forest (Fig. 1) document Outlook Sabatini FM et al. (2018) Divers Distrib 24: 1426-1439
the reduction of fir and spruce during the Old-growth forests have captured the atten- Schütz J-P et al. (2016) Ann For Sci 73: 911-921
Middle Ages, when the land was used for ce- tion of foresters and conservationists alike
Seidl R et al. (2017) Nat Clim Chang 7: 395-402
real crop cultivation and cattle herding, and (Fröhlich 1930). However, there are still sub-
after local, higher-severity catchment fires stantial conservation and restoration gaps, Vitasse Y et al. (2019) Eur J Forest Res 138: 547-560
occurred (Fig. 2). This evidence supports as primary and old-growth forests are only Whitlock C et al. (2018) Conserv Biol 32: 84-97
the notion that historical land-use pressure partially representative of the full range of
reduced the extent of old-growth forests. European forest types (Sabatini et al. 2018).
CC-BY PAGES MAGAZINE ∙ VOLUME 30 ∙ NO 1 ∙ April 2022
10 SCIENCE HIGHLIGHTS: Using Paleoecology in Restoration Ecology
doi.org/10.22498/pages.30.1.10
Understanding and enabling
variability in wetlands
Max Finlayson1 and Peter Gell2
Given changes due to the direct drivers of change in wetlands and the absence of suitable reference conditions, we
recommend that the Ramsar Convention on Wetlands develops guidance for managers to better understand the
nature and trajectory of change in wetlands, and to identify preferred ecological conditions.
The state of wetlands many wetlands were in long-term ecologi- (1) Loch Ruthven, Scotland
The Ramsar Convention on Wetlands (see cal decline long before listing as Ramsar Loch Ruthven (Fig. 1) was listed as a Ramsar
ramsar.org and Gell 2017 for background on sites, including those documented by Gell site in 1996 for its role in maintaining biodi-
the Convention) has reported that national et al. (2016). This points to a need to provide versity in a biogeographic region. Its Ramsar
governments are having difficulty in meeting information about the nature of change in Information Sheet1 (2006) identified it as a
their obligation to maintain the ecologi- wetlands, over a range of time-scales, and to mesotrophic lake, and identified its role in
cal character of internationally important improve understanding about their present supporting breeding pairs of the waterbird,
wetlands (Ramsar sites) and other wetlands condition and the importance of anthropo- the Slavonian Grebe. Short sediment cores
in their territory (Ramsar Convention on genic drivers. This includes understanding spanning almost 200 years revealed changes
Wetlands 2018; Convention on Wetlands whether paleoecological approaches could in the lake (Brooks et al. 2012). Diatom-
2021). This indicates a need to better under- be combined with other approaches to inferred total phosphorus revealed the lake
stand the drivers of change in wetlands to in- understand benchmarks of change, as well to have been oligo-mesotrophic before
form management decisions, and to identify as the rates and direction of change, both the 1920s; it is now approaching eutrophic
the trajectories of ecological change. historic and anthropogenic. levels. Preserved chironomid (midges) head
capsules (a measure frequently used in
Key obligations accepted by national Wetland wise use and long-term change palaeoecological and palaeoclimate stud-
governments under the Ramsar Convention Guidance for the wise use of wetlands has ies) showed that an increase in productivity
are to maintain the ecological character of been developed through the Convention drove increases in food resources for grebe
wetlands they designate as internationally to provide wetland managers with techni- chicks. This eutrophication trend, attributed
important (known as Ramsar sites), and to cal knowledge for making decisions for to increased cattle stocking, has increased
make wise use of other wetlands in their ter- managing and restoring wetlands, including the security of a key bird species, central to
ritory (Finlayson et al. 2011; Pritchard 2021). for restoring water regimes and limiting the the listing of the Ramsar site. Care will be
These concepts are defined as follows: (1) spread of invasive species. This guidance needed to avoid a critical transition that may
the ecological character of a wetland is has not hitherto included how to estab- impact the grebes and other biota.
the combination of the ecosystem compo- lish baselines for determining change in
nents, processes, and benefits/services that ecological character, nor how to respond to (2) Lake Urmia, Iran
characterize the wetland at a given point in variations and change due to climate change Lake Urmia (Fig. 2), listed as a Ramsar site2
time; (2) wise use of wetlands is the mainte- (Finlayson 2013). The examples outlined in 1975, was the world's second largest
nance of their ecological character, achieved below illustrate how investigations of past hypersaline lake until 1995 when the water
through the implementation of ecosystem change and trajectories can be important for level and area started to decline; it is now
approaches, within the context of sustain- managers. almost desiccated (Alizadeh-Choobari et al.
able development (Finlayson et al. 2011,
page 185). Hence, national governments
commit to maintaining or restoring wetland
ecosystems, their biodiversity, ecological
processes, and ecosystem services.
Ecological character of wetlands
The ecological character of wetlands is
a consequence of their history, and the
ecological trajectories that have been set
in place through natural succession and the
influence of humans. The former may have
occurred over millennia, with more recent
human impact arising from pollutants and
changes in land and water use within wet-
lands, and their catchments.
As the maintenance of the ecological
character of each Ramsar-listed wetland
is judged against an agreed baseline, it
is necessary to identify and describe that
baseline in sufficient detail for managers
to use as a reference, including accom-
modating natural variability and ecological
succession (Pritchard 2021). In some cases,
managers have accepted that the ecological
character at the time of listing as a Ramsar
Figure 1: Loch Ruthven has undergone eutrophication, attributed to increased cattle stocking (photo credit:
site was the appropriate baseline. However, S. Elliot).
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