Taxonomy and conservation | Rarity | Agencies |
The importance of taxonomy and herbaria to conservation
It is with good reason that "to document and understand plant diversity" is Target 1 of the Global Strategy for Plant Conservation [GSPC], Convention for Biological Diversity). Documenting and understanding plant diversity is a necessary prerequisite to assessing the conservation status of plant species and a precondition to meeting the GSPC goal of conserving 60% of the world’s threatened species in situ (Target 7 of the GSPC). Taxonomic understanding is an obligate prerequisite for any conservation work, guiding everything from rapid bioinventory, to official listing, species-specific biological inquiry, or management decisions.
Central to taxonomy is the delimitation of taxa at the rank of species and below (incl. subspecies or varieties). Critical to this work is the framework provided by herbaria and their collections, the rules of nomenclature (including typification), and the ever growing body of literature on plant evolution that informs our concepts of species.
The importance of herbaria
A herbarium is a collection of dried, pressed plants and associated collections data and library materials. Herbaria provide comparative material that is essential for studies in taxonomy, systematics, ecology, anatomy, morphology, conservation biology, biodiversity, ethnobotany, and paleobiology.
Among the most important specimens housed in herbaria are type specimens. Types are essentially name standards. They are the physical representation (usually a specimen, but there are exceptions) that fix the usage of a name. Without types, there could be no unambiguous communication about plants. Therefore, herbaria serve as the foundation of all disciplines in need of communicating information about plant species.
View this PowerPoint presentation for more information on typification and classification.
International Code of Nomenclature (ICN)
The ICN governs the application of names to plants. Without the ICN nomenclature would be chaos.
What is a species?
Defining species has been a complex problem in biology and many definitions have been proposed over the years. Some useful reviews of the problem with regard to plants were undertaken by Luckow (2005) and McDade (2005). By far the most widely adopted species concept by alpha-level taxonomists, that is, those working at the level of species and subspecies, rather than at the rank of genera and above, has been the Phylogenetic Species Concept (PSC) sensu Nixon and Wheeler. This concept holds that for sexually reproducing lineages, a species is the smallest aggregation of populations discernable by a unique combination of character states. If character states exist in unique combinations in given populations, they are hypothesized to be genetically fixed in those population, thus facilitating the recognition at the rank of species. Although subspecific recognition remains unequally applied, many workers recognize subspecies when there is evidence of statistical differences in quantitative characters correlated with some level of geographic discontinuity (i.e., this can be interpreted as evidence of incomplete divergence).
Causes
Natural: (1) rare habitat, (2) climate/habitat change/isolation => niche (fundamental vs. realized; narrow due to narrow tolerance of environmental factors or narrow [realized] due to competition)
Anthropogenic: (1) direct habitat destruction, (2) alteration of landscapes and landscape dynamics (fragmentation of habitats), (3) alteration of natural disturbance regimes, (5) exotic pest introductions, (6) direct exploitation (e.g., commercial collecting)
Top five threats in a recent PCP analysis were: development, fire suppression, incompatible forestry practices, hydrologic alteration, invasive species (these combined affect 73% of the rare flora in North Carolina)
How to measure imperilment
Ranking guidelines: IUCN red list
NatureServe Criteria: (1) total number and condition of occurrences (e.g., populations), (2) population size range extent and area of occupancy, (3) short- and long-term trends in the above factors. (4) scope, severity, and immediacy of threats, (5) number of protected and managed occurrences, (6) intrinsic vulnerability, (7) environmental specificity
New NC guidelines: take into account rarity, population size/viability, and threats
Figure. Final Protected Plant Listing Criteria (approved by PCP Scientific Committee August 2008)
Agencies involved in rare plant protection
Regulatory:
North Carolina Division of Agriculture & Consumer Services, Plant Conservation Program
Non-regulatory:
North Carolina Natural Heritage Program
Pertinent legislation:
(1) Endangered Species Act (ESA): From http://www.fws.gov/laws/lawsdigest/ESACT.html: "Through federal action and by encouraging the establishment of state programs, the 1973 Endangered Species Act provided for the conservation of ecosystems upon which threatened and endangered species of fish, wildlife, and plants depend. The Act: authorizes the determination and listing of species as endangered and threatened; prohibits unauthorized taking, possession, sale, and transport of endangered species; provides authority to acquire land for the conservation of listed species, using land and water conservation funds; authorizes establishment of cooperative agreements and grants-in-aid to States that establish and maintain active and adequate programs for endangered and threatened wildlife and plants; authorizes the assessment of civil and criminal penalties for violating the Act or regulations; and authorizes the payment of rewards to anyone furnishing information leading to arrest and conviction for any violation of the Act or any regulation issued thereunder. Section 7 of the Endangered Species Act requires Federal agencies to insure that any action authorized, funded or carried out by them is not likely to jeopardize the continued existence of listed species or modify their critical habitat."
(2) National Environmental Policy Act (NEPA): from blm.gov: NEPA "[...]ensures that [Federal] agencies [...] take environmental factors into account when considering Federal actions. NEPA does not mandate protection of the environment. Instead, it requires agencies to follow a particular process in making decisions and to disclose the information/data that was used to support those decisions.[...] NEPA requires agencies to follow a three-step review process: Conduct a preliminary screening for NEPA’s applicability [...]; Prepare an Environmental Assessment (EA) to determine whether an Environmental Impact Statement (EIS) is required; and Prepare an EIS if required (an EIS is required if a proposed action may “significantly affect the quality of the human environment”)."
(3) North Carolina Plant Conservation Act: authorized listing of species in the state and acquisition of land for conservation; established a board and advisory scientific committee.
(4) Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES): "aim[s] to ensure that international trade in specimens of wild animals and plants does not threaten their survival." Organized into three appendices:
"Appendix I lists species that are the most endangered among CITES-listed animals and plants (see Article II, paragraph 1 of the Convention). They are threatened with extinction and CITES prohibits international trade in specimens of these species except when the purpose of the import is not commercial (see Article III), for instance for scientific research." Examples: Sarracenia oreophila, S. jonesii
"Appendix II lists species that are not necessarily now threatened with extinction but that may become so unless trade is closely controlled. It also includes so-called "look-alike species", i.e. species of which the specimens in trade look like those of species listed for conservation reasons (see Article II, paragraph 2 of the Convention). International trade in specimens of Appendix-II species may be authorized by the granting of an export permit or re-export certificate." Examples: flytrap (Dionaea muscipula), ginseng (Panax quinquefolius), Cactaceae, Orchidaceae, Sarracenia spp. (all except those listed in Appendix I)
"Appendix III is a list of species included at the request of a Party that already regulates trade in the species and that needs the cooperation of other countries to prevent unsustainable or illegal exploitation (see Article II, paragraph 3, of the Convention). International trade in specimens of species listed in this Appendix is allowed only on presentation of the appropriate permits or certificates. Example: Cedrela odorata (Meliaceae): populations in Guatemala, Colombia, and Peru.