Conservation status of North American forest botanicals: What do we know? Why does it matter?

Leaman, Danna. Research Associate, Canadian Museum of Nature, Ottawa, Canada. Co-Chair, Medicinal Plant Specialist Group, Species Survival Commission, International Union for Conservation of Nature (IUCN); Trustee, FairWild Foundation. djl@green-world.org

(Presented at The Future of Ginseng and Forest Botanicals Symposium, July 12-14, 2017, Morgantown, WV)

Abstract

Based on the International Union for Conservation of Nature (IUCN) Sampled Red List Index, 20% of plants in the world are threatened with extinction.  According to NatureServe rankings, a larger proportion (26%) of the North American flora is threatened.  While NatureServe data are more complete for North American plant species, the more limited IUCN global Red List assessment data enable analysis of current knowledge of the conservation status of forest plants in North America and the extent to which they are threatened by biological use, including gathering.  The IUCN Plants for People initiative is focused on conservation assessment and action for economically important plants, including non-timber forest products (NTFPs).  This initiative invites broad collaboration to improve what we know about the conservation status of forest botanicals and other plant species important to livelihoods, health, and commerce in North America as a basis for conservation and sustainable use.

Keywords:  North America, plants, botanicals, non-timber forest products, conservation, sustainable use

What do we know about the conservation status of the world’s plant species?

An estimated 391,000 species of vascular plants are currently known to science (Royal Botanic Gardens/RBG Kew 2016).  Before 2010, only about 3% (12,873) of identified plant species were included on the global IUCN Red List of Threatened Species (RBG Kew 2012).  The majority of those species had been assessed because they are rare endemics or already thought to be threatened.  This gave a view of the overall conservation status of plants that was likely biased towards high proportions of threatened species.

Under the United Nations Convention on Biological Diversity (CBD), the Global Strategy for Plant Conservation (GSPC) set a target to achieve a significant reduction in the current rate of loss of [plant] biodiversity, by 2010 (United Nations Environment Program/UNEP 2002).  This target was revised for 2011-2020 to call for “an assessment of the conservation status of all known plant species, as far as possible, to guide conservation action” (UNEP 2011).  The limited number of plant global IUCN Red List assessments overall, and the bias towards including assessments of known threatened species in the IUCN Red List have stood in the way of achieving both targets.

In response to these obstacles, IUCN Red List programme and Red List Partners, including RBG Kew, launched the Sampled Red List Index (SRLi) for Plants and began regular conservation status assessments of a significant sample of the world’s flora (RBG Kew 2012).  Results of the first SRLi for plants included:

  • One in five species is threatened with extinction
  • Major threats to plant species worldwide are agriculture – conversion of plant habitat – and biological resource use.

IUCN, working with the plant specialist groups of the Species Survival Commission, and the botanic garden community, led by RBG Kew and Botanic Gardens Conservation International (BGCI), have developed some new plant conservation assessment approaches and tools.  These include:

  • many comprehensive plant assessments of complete taxonomic groups (e.g., cycads, conifers and gymnosperms, cacti and succulents)
  • regional Red List assessments for plants completed or in process (e.g., Europe, South Africa, Brazil, Madagascar)
  • annual State of the World’s Plants reports, led by RBG Kew (RBG Kew 2016, 2017)
  • ThreatSearch database, created by BGCI (2017).

However, economically and socially important plants – plants important to cultures and livelihoods – remain significantly under-represented in IUCN global and regional Red List assessments, including NTFPs and medicinal plants.  To address this gap, IUCN created the Plants for People initiative with a focus on medicinal, timber and non-timber trees, palms, and crop wild relatives (IUCN 2017a).

What do we know about the conservation status of North American plant species?

There are roughly 20,000 species of vascular plants in the North American flora (Flora of North America 2008).  Of these, NatureServe (2017) has ranked 17,355 species (87%). Just 1670 (less than 8%) of North American vascular plant species have published global Red List assessments (IUCN 2017b).  Figure 1 compares the results of searches on both platforms of the conservation status of North American plant species.  The two systems of threat classification have some differences in definitions and applications of factors (NatureServe) or criteria (IUCN), but are similar enough for this analysis.  Annex 1 provides a table comparing definitions of NatureServe ranks (Master et al. 2012) and IUCN criteria (IUCN 2012).

Fig 1. Comparison of the distribution of NatureServe ranks and IUCN Red List categories for North American plant species (n=20,000)

NatureServe Explorer data are far more comprehensive in their coverage of the North American flora than are global Red List assessments, and therefore are likely less biased towards threatened ranks in the overall distribution of conservation status results.  However, the IUCN Red List data and searchable attributes more readily provide insight into the conservation status of plants that occur in particular habitats (e.g., temperate forest), threats (e.g., biological resource use), and sub-categories of threat (e.g., gathering terrestrial plants).

The proportion of North American plant species assessed as threatened with extinction by NatureServe (NatureServe ranks G1 – Critically Imperiled, G2 – Imperiled, G3 – Vulnerable) is 26%, approximately equal to the proportion of North American plant species assessed as threatened (28%) by IUCN (IUCN Red List categories CR – Critically Endangered, EN – Endangered, VU – Vulnerable).  However, the proportion of North American species assessed by IUCN that met criteria for Critically Endangered is higher than the proportion of species ranked as Critically Imperiled by NatureServe (Figure 1).

What do we know about the conservation status of North American forest botanicals?

The IUCN Red List data (IUCN 2017b) were searched using the following sets of search criteria:

Search 1:  Taxonomy = Plantae; Location = Land regions/North America/Canada + United States; Habitat = Forest

Search 2:  Search 1 + Threats = Biological resource use

Search 3:  Search 1 + Threats = Biological resources use/gathering terrestrial plants

Results of these searches include the following:

  • Of the 1669 North American plant species assessed by IUCN, 670 (40%) occur in forests.
  • Forest plants in North America appear to be more threatened than the flora as a whole (CR, EN, VU forest = 40%; NA flora = 28%) (Figure 2a and b).
  • Biological resource use is a significant threat to 38% of North American forest species (Figure 2c).
  • Gathering terrestrial plants is a type of biological resource use that threatens 49% of North American forest species (Figure 2d).
Fig 2. Comparison of IUCN Red List assessment results for (a) all North American plants with IUCN Red List assessments (n=1,669), (b) all North American plants occurring in forests (n=670), (c) all North American forest plants threatened by biological use (n=89), (d) all North American forest plants with biological uses that are threatened by gathering (n=37)

What can we do with this knowledge?

The Medicinal Plant Specialist Group of the Species Survival Commission, IUCN, is proposing a North American project as part of IUCN’s global Plants for People initiative (IUCN 2017a).  This project is inviting collaboration with North American networks of medicinal plant and NTFP collectors, herbalists, the commercial herbal industry, botanists and citizen scientists, educational and research institutions, government agencies, and non-government agencies – broadly, the people working with plants important to people – to work on shared concerns about the long-term survival of these important plant species in North America.  Current efforts focus on five tasks:

Task 1.  Red List assessments of priority species of medicinal plants.  We hope to draft and publish Red List assessments for all economically important plant species in North America, but we need to start with some clear priorities.  These include:

  • Medicinal plant species listed in Appendices 1 and 2 of the Convention on International Trade in Endangered Species of Fauna and Flora (CITES) that occur in North America
  • North American plant species included in the World Health Organization (WHO) monographs (WHO 1999, 2002, 2007, 2009)
  • “At Risk” and “To Watch” species identified by United Plant Savers (UPS 2014)

Task 2.  Identification of in situ and ex situ conservation gaps (e.g., occurrence in botanic garden and genetic collections; protection of crop wild relatives; presence in and effectiveness of protected areas).

Task 3.  Assessment of vulnerability to climate change.

Task 4.  Integrated (in situ and ex situ) conservation strategies emphasizing sustainable wild collection, e.g., application of the FairWild Standard (FairWild Foundation 2010) and various degrees of cultivation, including woods-grown and reintroductions.

Task 5.  Communication of key actions needed with those who can and must act to conserve threatened species and ensure that those not currently threatened do not become so.

The goal of the Plants for People initiative is not simply to create a Red List of threatened forest botanicals and other economically important species in North America.  By better understanding the conservation status, the threats, and the conservation actions that can prevent the loss of these species, we can act to support the livelihoods, industries, health treatments, and the many additional benefits that people derive from these North American plant species.

References

FairWild Foundation (2010)  FairWild Standard. Version 2.0. FairWild Foundation, Weinfelden, Switzerland.   http://www.fairwild.org/documents/.  Accessed 10 July 2017.

Flora of North America (2008).  Flora of North America – Introduction.  Flora of North America Association.  http://floranorthamerica.org.  Accessed 10 July 2017.

IUCN (2012) IUCN Red List Categories and Criteria: Version 3.1. Second edition. IUCN, Gland, Switzerland and Cambridge, UK.  http://www.iucnredlist.org/technical-documents/red-list-documents.  Accessed 10 July 2017.

IUCN (2017a) Plants for People:  conserving the world’s most important trees, crop wild relatives, and medicinal plants.  International Union for Conservation of Nature.  https://www.iucn.org/theme/species/our-work/plants/plants-people.  Accessed 10 July 2017.

IUCN (2017b).  The IUCN Red List of Threatened Species 2017-1.  http://www.iucnredlist.org.  Accessed 10 July 2017.

Master, L., D. Faber-Langendoen, R. Bittman, G. A. Hammerson, B. Heidel, J. Nichols, L. Ramsay, and A. Tomaino (2012) NatureServe Conservation Status Assessments: Factors for Assessing Extinction Risk. NatureServe, Arlington, VA.

NatureServe (2017) NatureServe Explorer.  http://explorer.natureserve.org.  Accessed 10 July 2017.

RBG Kew (2012) Plants under pressure – a global assessment.  IUCN Sampled Red List Index for Plants.  Royal Botanic Gardens, Kew, UK. http://www.kew.org/sites/default/files/kppcont_027709.pdf.  Accessed 10 July 2017.

RBG Kew (2016) The State of the World’s Plants Report – 2016.  Royal Botanic Gardens, Kew.  https://stateoftheworldsplants.com/2016/report/sotwp_2016.pdf.  Accessed 10 July 2017.

RBG Kew (2017) The State of the World’s Plants Report – 2017.  Royal Botanic Gardens, Kew. https://stateoftheworldsplants.com/2017/report/SOTWP_2017.pdf.  Accessed 10 July 2017.

UNEP (2002) Report of the Sixth Meeting of the Conference of the Parties to the Convention on Biological Diversity.  UNEP/CBD/COP/6/20 (Annex I.  Decisions adopted by the Conference of the Parties to the Convention on Biological Diversity at its sixth meeting, The Hague, 7-19 April 2002.  Decision No. VI/9. Global Strategy for Plant Conservation, pp. 139-150.  https://www.cbd.int/doc/?meeting=cop-06.  Accessed 10 July 2017.

UNEP (2011) Report of the Tenth Meeting of the Conference of the Parties to the Convention on Biological Diversity.  UNEP/CBD/COP/10/19 (Annex.  Decisions adopted by the Conference of the Parties to the Convention on Biological Diversity at its tenth meeting, Nagoya, Japan, 18-19 October 2010.  Decision No. X/17.  Consolidated update of the Global Strategy for Plant Conservation 2011-2020, pp. 169-176.  https://www.cbd.int/doc/?meeting=cop-10.  Accessed 10 July 2017.

United Plant Savers (UpS) (2014) Species At-Risk.  https://unitedplantsavers.org/species-at-risk.  Accessed 10 July 2017.

WHO (1999) WHO monographs on selected medicinal plants, volume 1.  World Health Organization, Geneva.

WHO (2002) WHO monographs on selected medicinal plants, volume 2.  World Health Organization, Geneva.

WHO (2007) WHO monographs on selected medicinal plants, volume 3.  World Health Organization, Geneva.

WHO (2009) WHO monographs on selected medicinal plants, volume 4.  World Health Organization, Geneva.

Annex 1: Comparison of IUCN Red List categories and NatureServe ranks

NatureServe Rank and Definition

GX – Presumed Extinct (species)
Not located despite intensive searches and virtually no likelihood of rediscovery.

Extinct (ecological communities and systems)
Eliminated throughout its range, with no restoration potential due to extinction of dominant or characteristic taxa and/or elimination of the sites and ecological processes on which the type depends.

GH – Possibly Extinct
Known from only historical occurrences but still some hope of rediscovery. ere is evidence that the species may be extinct or the ecosystem may be eliminated throughout its range, but not enough to state this with certainty. Examples of such evidence include (1) that a species has not been documented in approximately 20-40 years despite some searching or some evidence of significant habitat loss or degradation; (2) that a species or ecosystem has been searched for unsuccessfully, but not thoroughly enough to presume that it is extinct or eliminated throughout its range.

G1 – Critically Imperiled
At very high risk of extinction or elimination due to extreme rarity, very steep declines, or other factors.

G2 – Imperiled
At high risk of extinction or elimination due to very restricted range, very few populations or occurrences, steep declines, or other factors.

G3 – Vulnerable
At moderate risk of extinction or elimination due to a restricted range, relatively few populations or occurrences, recent and widespread declines, or other factors.

G4 – Apparently Secure
Uncommon but not rare; some cause for long- term concern due to declines or other factors.

G5 – Secure
Common; widespread and abundant.

G#G# – Range Rank
A numeric range rank (e.g., G2G3, G1G3) is used to indicate uncertainty about the exact status of a taxon or ecosystem type. Ranges cannot skip more than two ranks (e.g., GU should be used rather than G1G4).

GU – Unrankable
Currently unrankable due to lack of information or due to substantially conflicting information about status or trends. Note: whenever possible (when the range of uncertainty is three consecutive ranks or less), a range rank (e.g., G2G3) should be used to delineate the limits (range) of uncertainty.

GNR – Unranked
Global rank not yet assessed.
GNA – Not Applicable
A conservation status rank is not applicable because the species or ecosystem is not a suitable target for conservation activities.

IUCN Red List Category and Definition

EX – Extinct
A taxon is Extinct when there is no reasonable doubt that the last individual has died. A taxon is presumed Extinct when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle and life form.

EW – Extinct in the Wild
A taxon is Extinct in the Wild when it is known only to survive in cultivation, in captivity or as a naturalized population (or populations) well outside the past range. A taxon is presumed Extinct in the Wild when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle and life form.

CR – Critically Endangered
A taxon is Critically Endangered when the best available evidence indicates that it meets any of the criteria A to E for Critically Endangered (see Section V), and it is therefore considered to be facing an extremely high risk of extinction in the wild.

EN – Endangered
A taxon is Endangered when the best available evidence indicates that it meets any of the criteria A to E for Endangered (see Section V), and it is therefore considered to be facing a very high risk of extinction in the wild.

VU – Vulnerable
A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable (see Section V), and it is therefore considered to be facing a high risk of extinction in the wild.

NT – Near Threatened
A taxon is Near Threatened when it has been evaluated against the criteria but does not qualify for Critically Endangered, Endangered or Vulnerable now, but is close to qualifying for or is likely to qualify for a threatened category in the near future.

LC – Least Concern
A taxon is Least Concern when it has been evaluated against the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread and abundant taxa are included in this category.
No equivalent category

DD – Data Deficient
A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status. A taxon in this category may be well studied, and its biology well known, but appropriate data on abundance and/or distribution are lacking. Data Deficient is therefore not a category of threat. Listing of taxa in this category indicates that more information is required and acknowledges the possibility that future research will show that threatened classification is appropriate. It is important to make positive use of whatever data are available. In many cases great care should be exercised in choosing between DD and a threatened status. If the range of a taxon is suspected to be relatively circumscribed, and a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified.

NE – Not Evaluated
A taxon is Not Evaluated when it has not yet been evaluated against the criteria.
No equivalent category

5A global conservation status rank may be not applicable for several reasons, related to its relevance as a conservation target. In such cases, typically the species is a hybrid without conservation value, of domes c origin, or the ecosystem is non-native, for example, ruderal vegetation, a plantation, agricultural field, or developed vegetation (lawns, gardens etc).