Tree Collections Policy




Adopted by the Advisory Board and approved by Dr. Peter Likins.
January 2003
      The University of Arizona Campus Arboretum
      Purpose of Policy
      Responsibility for Implementation and Review
      Primary and Support Collections
      Responsibility for Records System Upkeep
      Timeliness of Records Upkeep
      Plants to be Accessioned
      Minimum Information Required
      Periodic Inventory and Evaluation
      Selection Criteria
      Initiation and Approval of Acquisitions
      Legal and Ethical Aspects of Acquisitions
      Collection Planning
      Safeguarding Collections
      Transplanting Large Specimens
      Decision to Deaccession
      Principles Governing Disposition
      Release of Germplasm
      Special Access


The University of Arizona Arboretum comprises all space on which the University has developed facilities: the Main Campus from Euclid to Campbell Avenue and from Sixth Street north, across Speedway, to the space surrounding the University Medical Center. All plantings on UA property, adjoining UA buildings, and/or defining University open space, in Pima County, Arizona, may be considered as a part of the University of Arizona Arboretum.
The Mission of the Campus Arboretum at The University of Arizona is to provide conservation and stewardship of urban trees through research, education, and outreach.
Purpose of UA Campus Arboretum Collections Policy 
The Purpose of the Collections Policy is to provide guidance and focus to those charged with the planning, development and management of the plant collections of the University of Arizona Campus Arboretum, with the aim of optimizing utilization of available resources to realize the Campus Arboretum's mission through effective and appropriate collections development.
The primary collections of the UA Campus Arboretum are its collections of living plants. A secondary, voucher collection of plants is housed at the University of Arizona Herbarium (ARIZ), a unit mandated by the State of Arizona. The above-cited purposes govern the Arboretum's collections of living plants.
Responsibility for Implementation and Review of the Policy
Collection planning to identify specific species acquisition and collection development priorities is the charge of the Collections Committee, with assistance from the Advisory Board's New Plants Committee. Collection planning will be engaged in on an ongoing basis, with annual review of specific collections plans taking place as noted below.
Periodic review and recommendations for revision of this Policy shall be the responsibility of the Collections Committee, following formal suggestions from the Campus Arboretum Advisory Board. The Collections Committee shall meet at least once every three years, or at the call of its Chair, to review and recommend revisions to this Policy.
The administration of the Policy is the responsibility of the Director, and the implementation of the Policy is the responsibility of the staff.


The Mission of the University of Arizona Campus Arboretum is to preserve, manage, enhance and expand a vital collection of plants in an active urban Sonoran Desert setting, and to showcase the historic, aesthetic, environmental, economical, and educational value of these plants within our community and the American Southwest. Plants accessioned into the University of Arizona's Collection must assist in fulfilling this mission. 
To accomplish this mission on the grounds of the University of Arizona requires flexibility. The Campus Arboretum recognizes the need to work with Planning, Design, and Construction, Facilities Management and other inter-related units to develop efficient and practical methods for realizing the goals of stewardship of, and education about, the campus plant collection as it contributes to the larger Tucson urban forest.


The UA Campus Arboretum is committed to the maintenance of accurate, up-to-date, and pertinent records on its accessioned living collections.
Plants to be Accessioned
All trees will be accessioned. When they are healthy enough, and reproductive, all tree specimens will be vouchered with the UA Herbarium. Shrubs, accents, grasses, and annuals may or may not be accessioned or vouchered. Plants obtained for temporary educational or research purposes may or may not be accessioned or vouchered.
Responsibility for Records System Upkeep 
The Registrar of Collections is responsible for the maintenance of current, thorough and accurate input into the records system of information pertinent to the plants within the living collection. Plant classification questions of a technical nature will be addressed to an acknowledged taxonomic authority or reference. Providing information pertaining to planned (and actual) installations is the responsibility of those supervising the project: staff from Planning, Design, and Construction or Facilities Management. Providing information pertaining to status of an accessioned item (e.g. change of location, death, removal) is the responsibility of the Facilities Management staff. The administration and oversight of the plant records system is the responsibility of the Director of the Arboretum.
Timeliness of Records Upkeep
Information concerning germplasm destined for inclusion in the Arboretum's living collections will be submitted to the Registrar of Collections or to the Director. This information will be entered into the UA Campus Arboretum’s database within four weeks of their installation. New plants which are part of a larger construction project should be submitted as an “As Built” list as soon as possible after final walk-through. Changes in the status of an accessioned item (e.g. change of location, death, removal) must be noted in the plant records system as soon as possible after the status change has taken place
Minimum Information Required
Information pertinent to the accession's taxonomic classification, place of origin, provenance type, source, date of acquisition, date planted, and mapped location will be kept on all items in the living collections. Data will also be kept with the voucher specimens at the UA Herbarium. Additional information will be kept on specific plants as is needed and practical. The Arboretum will review its plant Names on a regular basis (rotation not to exceed five years) to insure that current taxonomically Accepted Names are utilized whenever possible. The responsibility for this effort will be that of the Collections Committee, under the direction of the Chair, as requested by the Arboretum Director.
Periodic Inventory and Evaluation
Field inventory and evaluation of the living collections will be carried out periodically in order to verify the current status of the collections (living or dead, location) and is the responsibility of the Director.


Living plants acquired by the University of Arizona Campus Arboretum should meet the goals and objectives of the Arboretum, as defined by the Mission Statement, and be in accordance with the selection criteria delineated in this Policy. New plants to be specified in contracts for new buildings on campus should fall within the Campus Arboretum’s selection criteria, as well.
It is of fundamental importance that plants only be acquired by the Arboretum when proper maintenance and care can be assured for them in terms of staff time, water, facilities, and space. Collaboration with personnel in Planning, Design, and Construction, Facilities Management, and the Planning and Design Review Advisory Committee (PADRAC) will enable good communication regarding appropriate plant material.
Selection Criteria
As noted above under Purpose, plants selected for acquisition by the Campus Arboretum should have an emphasis on adaptation to arid or semi-arid conditions or serve some educational value if otherwise. For the purpose of this Policy, arid and semi-arid regions shall be defined as those receiving annual rainfall of under 250 mm (10 inches) and under 500 mm (20 inches) respectively. Acquisitions should be adapted to the ambient temperature conditions of the site. For practical purposes, this means that specimens should be able to withstand minimum temperatures of -5C to -8°C (22 to 18°F) for brief periods when mature, and extended maximum temperatures of 42°C (107.6°F) or more in summer. It is recognized that specific microclimates on the UA Campus may allow use of species that would otherwise not be adapted to normal weather in Tucson, AZ.
In addition to the environmental criteria noted above, primary plant selection criteria to be applied to potential acquisitions are:
  1. Educational/interpretive or research potential
  2. Functional or landscape potential
  3. Preservation of rare cultivated plants, especially those which honor the University’s heritage
  4. Dominance or importance within a pertinent eco-geographic region
  5. Economic or ethnobotanic utility
  6. Ex situ conservation of taxa.
Acquisitions may be field collected (with proper permits and documentation), salvaged from sites undergoing construction (if properly documented), or come from other botanical institutions, field collectors, commercial sources, or gifts.
Initiation and Approval of Acquisitions
Recommendations for acquisitions to the collections can be initiated by staff, volunteers, persons serving on the Arboretum Advisory Board or Board Committees, or interested members of the campus community and the general public. Acquisitions of individual plants or a small collection are initiated by submitting a Plant Acquisition Proposal Form to the Collections Committee. Half of the members of the Collections Committee will constitute a quorum for the purpose of making recommendations concerning accessions. Approval of the species is separate from its actual acquisition.
New species for consideration may also be suggested by the Advisory Board’s New Plants committee, with consultation/discussion with the Collections Committee. Minor acquisitions can be accepted by the Horticulturist/ FM staff person responsible for their care. Records on these species, and a general report to the Collections Committee, will allow evaluation for future permanent use. Major acquisitions may arrive as part of campus construction project contracts. Project plant lists will be approved by the Collections Committee and/or the Director as part of the design review process. Acquisitions of plants installed as part of large Planning, Design, and Construction projects are to be submitted as ‘as built lists’ through Planning, Design, and Construction or Facilities Management. These lists should be submitted to the Collections Committee or Director as soon as possible after final walk through.
Legal and Ethical Aspects of Acquisitions
The University of Arizona Campus Arboretum is committed to adhering to all laws, regulations, and conventions, be they state, national or international in scope, which govern and regulate the taking and transport of protected taxa.
The Campus Arboretum shall have on file a current copy of the policies and lists of the Convention on International Trade of Endangered Species (CITES). The Campus Arboretum recognizes that other botanical gardens and arboreta may choose to adhere to those policies in acquisition of living plants, propagules and seeds; our policy will be one of cooperation and respect for those institutions’ guidelines.
The Arboretum will not acquire such taxa if any doubt or apprehension exists concerning their origin or method of acquisition. Properly documented donations of protected taxa will be accepted. Where doubt exists as to origin of an individual taxa, appropriate authorities will be consulted.
The University of Arizona Campus Arboretum is committed to adhering to all laws, regulations, and conventions, be they state, national or international in scope, including the Convention on Biological Diversity (CBD), which pertain to sharing of benefits resulting from the acquisition of germplasm; and which govern Plant Breeder’s Rights (PBR) and other intellectual property rights.
The University of Arizona Campus Arboretum is committed to adhering to all laws, regulations, and conventions, be they state, national or international in scope, which govern and regulate the acquisition and transport of organisms constituting a known bio-hazard (noxious weeds, invasive species, or pests). The Arboretum recognizes The Arizona Department of Agriculture as the state authority on endangered plant species, plant protection laws and noxious weeds. The Arboretum is committed to taking a pro-active, careful and watchful posture as regards the introduction into the local ecosystem of potentially invasive, aggressive or noxious ecosystem weeds, as well as any diseased or infested individuals.
All potential acquisitions presented to the Arboretum as gifts are subject to the same policies and selection criteria as outlined for acquisitions in general. Plants that are offered as gifts are initiated by the Plant Acquisition Proposal Form. Acquisitions received as gifts are considered unconditional in regard to the eventual disposition of the gift. The Arboretum reserves the right to display or not display, give away, or destroy the acquired gift. Any special situations in which legally binding restrictions or conditions on the disposition of a gift may be deemed appropriate shall be reviewed by the Collections Committee with a quorum present. The resulting recommendation from the Committee shall be made to the Advisory Board of the Arboretum, who may seek gifts as to value.


The living collections of the UA Campus Arboretum are to be maintained in as healthy and attractive a state as is practical by Facilities Management, given the ambient conditions of the University of Arizona Campus and its many uses. Collections of rare or valuable species shall receive priority care. High public profile plants are considered as high priority collections as far as level of maintenance is concerned. If an item in the collections is not performing adequately under the above regime, it should be considered for de-accessioning.
Pro-active salvage and propagation efforts are valuable. Collaboration between the Campus Arboretum and Planning, Design, and Construction will allow propagation of species that may be vulnerable to construction projects or that are not performing well, as well as identification of valuable trees that may be protected in place during construction. Salvage is possible with some species, though not all species warrant the risk.
Drafting and periodic review of a Plant Germplasm Emergency Salvage Guidelines document shall be the responsibility of the Collections Committee.
Safeguarding Collections
The UA Campus Arboretum is committed to horticulturally safeguarding its living collections within the limits of accepted professional horticultural practices and the constraints of the ambient climatic/environmental conditions of the University of Arizona campus, as noted above. The Arboretum shall safeguard its collections from breaches of security by employment of adequate and practical risk management procedures. In the case of imminent loss of unique or rare germplasm, salvage operations will be initiated as per the Plant Germplasm Emergency Salvage Guidelines. Propagation of unique or rare germplasm will be undertaken whenever feasible.
Collections Records shall be safeguarded by means of adequate security provisions and records backup. The UA Campus Arboretum will cooperate with Planning, Design, and Construction to ensure proper records backup.
Transplanting Large Specimens
The Arboretum Director shall provide advice and make reasonable efforts to evaluate the costs and benefits of transplanting historic, rare or otherwise significant specimens, versus the costs/benefits of retaining such specimens on site. A key element of proper transplantation is choice of proper microhabitat, with which the Collections Committee can advise. The UA Campus Arboretum Tree Valuation (September, 2002) documents give further guidelines and techniques for evaluating the majority of campus trees.


It is the policy of the University of Arizona Campus Arboretum that its collections be maintained in the public interest. It is realized, though, that at times it may be in the public interest to remove certain materials from the collections. The following policy applies to material owned by and accessioned into the permanent collections of the Arboretum.
Deaccessioning and disposition of dead or hazardous plants shall be handled in accordance with established University of Arizona procedures. Discussion between Grounds Services and a member of the Arboretum Collections Committee is preferred prior to removal. A report summarizing losses shall be submitted to the Collections Committee and Registrar of Collections after a loss has been noted. (Email is OK). The final decision on disposition of dead or hazardous plants lies with Grounds Services, after consultation with representatives of the Campus Arboretum.
Living plants require more forethought. Living plants may be in poor health or chronic decline. They may not be good representatives of their species, nor lend themselves to horticulture display. Requests to deaccession living plants, particularly including the disposal or transplant of large older specimens (including any vulnerable to construction projects) will be submitted to the Collections Committee, with discussion to include justification from the point of view of Grounds Services. People in a position to contact the Campus Arboretum Collections Committee to discuss removal or disposal include Facilities Management workers, Campus Planning, Design, and Construction personnel, and anyone involved in design review. A quorum (conference call, or email is OK) will be required for any major removal of living plants (whether or not they represent the last member of an accession). The final decision on disposal of individual living plants lies with Grounds Services, after consultation with representatives of the Campus Arboretum. In any case, the decision to dispose of a living tree should be consistent with the goals and mission of the Campus Arboretum. 
Donor trees or named trees have the added requirement that the donor be contacted. The Campus Arboretum's Donor Policy describes the rights and expectations regarding disposal of old living things which have been adopted by donors. Final decision on whether to dispose of named trees, or donor trees, requires an agreement between the Arboretum Director and a representative of Facilities Management.
It is important to avoid unreasonable conflict. At times an public expert's opinion may be sought regarding a valuable or high profile tree.
A. The decision to deaccession an individual plant may be made for the following purposes:
  • To insure that dead accessions are properly reflected in the Arboretum's record system
  • To remove plants that are damaged beyond reasonable recovery such that they do not retain their value
  • To record stolen plants or missing plants in the collection system
  • To make reasonable accommodations to UA construction projects or infrastructure changes; however, every effort shall be made to preserve or transplant accessioned living     specimens during planning stages of the project, as noted above
  • To permit destructive analysis, provided that the information expected to be obtained is deemed to outweigh the value of the specimen and its possible future use
  • To remove material that is potentially hazardous to other collections or to human health; or which may become invasive and damaging to the environment
  • To transfer to another arboretum, botanical garden, zoo, museums, or educational or scientific institution, material that is deemed by the Campus Arboretum to be significantly more useful and relevant to the collections and programs of the other institution than to those of the Arboretum
  • To carry out mutually beneficial exchanges of materials with other arboreta, botanical gardens, zoos, museums, or other educational or scientific institutions
B. The following restrictions will apply to deaccessioning:
  • No transaction will be carried out if it violates state, federal, or other applicable laws, or University of Arizona policy
  • All records (including those of the UA Herbarium) will be updated
C. The following principles will govern disposition:
  • If a plant is not healthy, it may be destroyed in accordance with health and sanitation regulations
  • Whenever possible, disposition of healthy plants shall be to other arboreta, botanical gardens, zoos, museums, or educational or scientific institutions by exchange of material or services
  • No exchanges or privately arranged sales may be made except to other museums or educational or scientific institutions, unless such sale benefits the species, the Campus Arboretum or another University of Arizona interest


The living display collections located on the University of Arizona campus, as indicated by UA and Campus Arboretum maps and directional signage, are open to the visiting public. Access to the plant collections records and significant requests for information from the collections records shall be referred to the Arboretum Director or Registrar of Collections.
Release of Germplasm from the UA Campus Arboretum 
Release of germplasm shall be subject to the provisions of the CBD under the authorization of the Director. Provision of limited numbers of propagules and other tissue from the living collections may be authorized by the Director provided that the manner of acquisition does not endanger the health or appearance of the chosen plant. Access to the collections for the purpose of obtaining propagules and tissue may be granted to public or private botanical, educational, and horticultural organizations. This is particularly important in the case of taxa that are not practically available elsewhere and for which introduction into the trade is deemed worthy. Availability of propagules and tissue for potential commercialization shall be subject to written agreements approved by the governing authorities of the University of Arizona.
The University of Arizona Campus Arboretum is committed to adhering to all laws, regulations, and conventions, be they state, national or international in scope, which pertain to sharing of benefits resulting from the acquisition of germplasm.
Special Access 
Access to the records by persons other than those on the Collections Committee will be grantable by Arboretum staff and will be by appointment. The Director will be made aware in advance where possible, that members of the general public have been granted special access to the collections or records.


The act of formally including an item or group of items in a managed collection. Implies a commitment to long-term care and the keeping of records about the accession (see acquisition.)
Physically taking possession of an item which will be included in a managed collection. Installation is a synonym.
Ambient temperature
Temperatures naturally prevailing at the site.
Arid land plants
Referring to plants adapted to water stress, usually by virtue of having evolved in areas with an arid or semi-arid climate.
Plants or organisms that are known, or have potential, to become invasive or cause damage to local flora.
Convention on Biological Diversity.
Convention on International Trade in Endangered Species.
The act of formally deleting an item from a managed collection.
The act of removing a plant, either dead or alive.
Ecosystem weed
An organism not native to the local eco-system, which exhibits the potential to aggressively reproduce, disrupting eco-system processes in a one-way direction thereby displacing indigenous species and lowering system biodiversity.
An unforeseen occurrence; a sudden and urgent occasion for action.
The genetic material comprising the fundamental information governing the development of a particular organism and carried in each cell of the organism.
Governing authorities
The Arizona Board of Regents.
Known wild origin
Having specific, reliable knowledge, either firsthand or otherwise, of the geographic location of the original collection site of an acquisition.
Major acquisitions
Whole collections offered for donations, long-lived perennials, and other plants in large numbers to which the Arboretum must make either a major short-term or long-term commitment.
Minor acquisitions
Annuals, short-lived perennials, or functional plants, all in relatively small numbers, to which the Arboretum has neither a major short-term nor a long-term commitment.
Naturalized Plant
Occurring spontaneously from historically introduced germplasm.
Primary plant selection criteria
Criteria by which a given potential acquisition is evaluated as to its appropriateness to the Arboretum's stated goals and objectives as outlined in this Policy.
Units of germplasm utilized to create new individuals, e.g. seed, cuttings, bulbs, etc.
Protected taxa
Taxa listed as rare, threatened or endangered, either by the U.S. Fish and Wildlife Service, the Arizona Department of Agriculture, or by the Botanic Gardens Conservation International.
Specialty collections
Plant collections organized along particular thematic lines.
A distinct sub-set of a larger collection.
Taxonomic classification
The place in the evolutionary order of organisms (phylogenetic position) to which an organism is assigned by a specialist known as a systematist or a taxonomist.
Taxonomic collections
Plant collections organized along systematic (phylogenetic) lines. i.e. arranged by family or genus, e.g. Desert Legume Collection, Cactus and Succulent Collections.