Principle – Ecological Integrity

Criterion- Genetic Diversity

Indicator – Use of scientifically-based seed transfer rules and seed orchard zones in planting native species.

Box B: Definition:

Indiscriminant movement of tree seed may not only result in poorly adapted artificial regeneration, but also in loss of local adaptations in surrounding natural stands of the same species (Ledig 1992). Seed transfer rules are based on estimates of the amplitude of adaptive traits using common garden experiments (Ledig 1996). Seed orchard zones are based on performance of progeny in test locations spanning a range of environmental conditions, and are intended to minimize genotype x environment interactions.

The indicator measures whether tree planting is introducing genes to an area that may mix with local populations and may not be adapted to the site conditions, through forestry-mediated migration.

Box D: Applicability to Different Landowners. Explain any differences.

N/A

Box E: Overlap:

CIFOR – 2.2.4 (S4) Enrichment planting

Notes:

This indicator could be tracked at any of the levels but is most readily tracked at the tenure level. Tracking at the level of site would also be appropriate.

Notes:

The indicator is diagnostic in that if rules are not being followed, it indicates a potential problem, and predictive in that potential genetic problems are not likely not to be manifested until years later.

Notes:

This indicator refers to the genetic composition of populations of tree species that are planted, as well as the genetic process of migration.

Box I: Underlying Concepts:

Migration is a genetic process that contributes to diversity and adaptation of natural populations. It refers to the movement of genes among populations. For plants, this means pollen or seed movement. Effects of increased migration may be positive or negative depending on the degree of specialization of populations (Namkoong et al. submitted). For most species, some migration is essential to avoid effects of genetic drift and inbreeding, particularly in small populations. Local adaptations arise, however, in heterogeneous environments and even a low rate of migration of maladapted genetic material may negatively impact local populations, depending on the strength of natural selection. Ledig (1996) pointed out that defining seed transfer rules is one of the most important tasks in conserving and managing forest genetic resources. Before results of provenance trials are known, seed zones are based on expert opinion using elevation, latitude, rainfall patterns, and localized knowledge of adaptive patterns.

Seed transfer rules and use of seed orchard planning zones are designed to reduce the possibility of planting maladapted trees that may contaminate local populations when they reach reproductive maturity. This is especially important in areas where natural populations may be small and large plantations could provide sufficient pollen to genetically swamp local populations.

Box J: Relevance to Sustainable/Unsustainable Management:

Maintaining locally adapted gene complexes where they occur is an important component of sustainable forest management. The planting of maladapted seedlings in close proximity to natural stands of the same species presents a clear danger to locally adapted genetic material.

CCFM:

"One task of foresters is to ensure that seedlings thrive when planted in harvested areas. They must track seed sources for greenhouse- and nursery-grown seedlings, and not plant them in areas where they will be exposed to climatic conditions vastly different from those experienced by their parents. Most provinces have designated seed-transfer zones for this purpose."

Maladapted genes would be expected to be weeded out in time through natural selection if local populations of sufficient size remain, and the relative concentration of migrant genes declines, but losses of adaptive gene complexes could be incurred in the interim.

A problem is likely when plantations of non-local native species are larger than the local populations, which may exist as scattered trees, so that the pollen cloud is dominated by the introduced sources. Natural selection pressures for local adaptations may not be continuous; for example an important local adaptation may be for the 20 year frost event or a similar drought event. Thus genetic swamping of local populations coupled with overstory removal of the naturally regenerating forest could result in substantial losses of locally adapted gene complexes in the offspring.

Box K: Measurement Methods:

In evaluating any genetic indicators, first the target species must be identified. The species of interest for this indicator are only those that are planted in the study area. The following set of questions must be answered:

• Which species are planted?
• Where does the seed come from?
• Is it genetically improved?

• Are plantations of improved trees established adjacent to natural populations of the same species?
• Are scientifically sound seed transfer rules or breeding zones utilized?
• Have previously isolated populations been brought together through planting?

To assess this indicator:

1. Check rules for forest management and Best Management Practices for the study area to determine whether following seed transfer rules must be followed in reforestation.
2. Check with local silviculturists and forest geneticists in the region for information about the seed transfer rules and seed orchard zones.
3. Determine how the rules or zones were developed and if they are being followed by the land managers in the study area.

Box L: Data Required:

See above

Box M: Data Used for the North American Test:

Information came from published research papers describing the development of expert systems for seed transfer and discussions with Idaho forest geneticists and others.

Box N: Example Results:

In the past maladapted seedlots were used for planting ponderosa pine and lodgepole pine in Idaho including plantations within the study area. There are concerns about the ongoing efects of these plantations contaminating surrounding natural populations. There is no evidence of present day transfer of seed beyond zones of ecological adaptation.

Most regeneration in the study area is natural, with only a small amount of artificial reforestation with ponderosa pine, Douglas-fir, Engelmann spruce, western larch and lodgepole pine. Almost all seed comes from managed Seed Production Areas or Seed Collection Stands.

The state requires that an "expert system" be used for all planting to ensure locally adapted seed sources are used. The expert systems are based on work of USFS forest genetiicist, Jerry Rehfeldt who has researched ecological amplitudes of all of the species planted in the state (1989, 1991. 1991, 1994). Expert systems have been completed for all planted species except lodgepole pine, which is still in progress. Development of these expert systems is based primarily on response of provenances until the age of 5 years in common garden studies at different latitude and elevations. The response is measured in terms of a wide range of traits related to growth rate and adaptation and modeled using multiple regression equations, for latitude, longitude and elevation.

An example of a seed transfer decision making facilitated by an expert system is provided by Rehfeldt (1991b). He explains that based on the model, "to maintain the adaptedness typical of natural populations on a planting site at 1100 m in the Spokane drainage, seeds could be imported from elevations between 700 and 900 m in the Sanpoil drainage, 800 and 1200 m in the Colville drainage, 800 and 1300 m in the Clearwater drainage, 600 to 1100 m in portions of the Kootenai drainage and 800 to 1200 m in both the Clarkfork drainage and the Spokane drainage itself. Alternatively, seeds from a seed production area located at the same site could be planted at the sites indicated without a loss in adaptedness."

According to state geneticists, everyone planting any significant number of trees uses the best information available (expert system or in the case of lodgepole pine, seed zone based on longitude and latitude, adjusted by elevation). Minor concern was expressed that small numbers of trees planted by NGO organizations in restoration projects may not be planted following the expert systems, because of lack of knowledge.

Box O: Assessing the Practicality:

This indicator is very easy to track.

Box P: Assessing the Information Value:

The information value is good for the effort expended.

Box Q: Overall assessment:

Accepted

Strength: very easy to assess. Provides basic information about the application of genetically acceptable practices in planting programs.

Box R: Did you rewrite or revise to a new indicator. If so what?

This is a new indicator

Box S: References:

• Canadian Council of Forest Ministers. 1997. Criteria & Indicators of Sustainable Forest Management in Canada. Technical Report. Cat. Fo75-3/6-1997E, ISBN 0-662-25623-9. Natural Resources Canada–Canadian Forest Service 8th floor, 580 Booth Street,Ottawa ON
• Ledig, F.T. 1992. Human impacts on genetic diversity in forest ecosystems. OIKOS 63: 87-108
• Ledig, F. T. 1996.Box 7: Management of genetic resources by controlling seed movement. In The Status of Temperate North American Forest Genetic Resources. D.L. Rogers and F.T. Ledif (Eds.), Report No.16, Genetics Resources Conservation Program, Division of Agriculture and Natural Resources, University of California, Davis, California.
• Namkoong,G., T. Boyle, Y. El-Kassaby, G. Eriksson, H.-R. Gregorius, H.Joly, A. Kremer, O. Savolainen, R. Wickneswari, A. Young, M. Zeh-Nlo, and R. Prabhu. Criteria and indicators for assessing the sustainability of forest management: conseration nof genetic diversity. AMBIO. (submitted 1997)
• Refeldt, G.E. 1989. Ecological adaptations in Douglas-fir (Pseudotsuga menziesii var. glauca): a synthesis. For. Ecol. Manage., 28: 203-215
• Rehfeldt, G.E. 1991a. Gene resource management: using models of genetic variation in silviculture. In: Proc. Genetics/Silviculture Workshop. Aug. 27-31,1990,Wenatchee, Washington. USDA, Forest Service, pp 31-44.
• Rehfeldt, G.E. 1991b. A model of genetic variation for pinus ponderosa in the Inland Northwest (U.S.A.): applications in gene resource management. Can. J. For. Res. 21: 1491-1500
• Rehfeldt, G.E. 1994. Adaptations of Picea engelmannii populations to the heterogeneous environments of the Intermountain West. Can. J. Bot. 72: 1197-1208

Please record your notes on evaluating the indicator here