That's a very intelligent question and we  keep debating this issue quite often . Infact good high quality seedling is no guarantee to long term performance of the plant  . Under reforestation project , quality planting material will ensure good establishment , will be minimum mortality due to abiotic stress during plant establishment stage , but later there is no guarantee to better plant performance . It largely dpends upon the site characteristics , its microbial flora composition , rainfall , time of planting  , post-planting care etc etc ... Its like a healthy child is born in hospital , you bring healthy child at home , but rest will depend upon your management ...

I agree with Anoop Srivastava, we cannot forget the future forest management.  However, I consider that high quality plant increases the possibility to have a good performance in the future. Particularly if you mean by high quality seedlings,  vigorous plants, shoot/root ratio well balanced, but you should not forgot the genetic origin of the Forest Reproductive Material in order to promote the adaption to the site you are planting. Be aware that Local provenances may not always be the best source of FRM. I suggest the reading of Konnert, M., Fady, B., Gömöry, D., A’Hara, S., Wolter, F., Ducci, F., Koskela, J., Bozzano, M., Maaten, T. and Kowalczyk, J. European Forest Genetic Resources Programme (EUFORGEN). 2015. Use and transfer of forest reproductive material in Europe in the context of climate change. European Forest Genetic Resources Programme (EUFORGEN), Bioversity International, Rome, Italy. xvi and 75 p. (download from http://www.foresteurope.org/news/five-important-publications-euforgen-last-five-years%E2%80%99-work)

Both responses are absolutelly true.  Currently, I have been working with Cedrela odorata and I have seen that even though the plants used to reforest have the appropiated morphological and physiological traits, these are not able to overcome in a long-term different selective pressures either biotic or abiotic, for example shoot borer insects or bad soil drainage. I have only found a good field-performance during the first-stages of outplantig (less than one year), in spite of using high quality seedlings.

I do not have the answer at the tip of my tongue, but issues of seed quality and reforestation have been part of the silvicultural research for some time.  To get a handle on the research, I would look at older issues of Journal of Forestry, the United States Forest Service Research Station publications, and silvicultural and forest restoration textbooks.

Early establishment and performance is related to high quality of the seeds and seedlings; mid term performance is highly correlated to early performance; see paper attached

cheers

c

Thank you  Cristina Martinez, the paper is quite interesting. It will be so useful to discuss my founds.

My experience is that using the "optimum seedling" will lower the overall cost of plantation establishment by lowering the cost of weed control.

Determining the "optimum" slash pine seedling size for use with four levels of vegetation management on a flatwoods site in Georgia, U.S.A.

David B South, Robert J Mitchell

Canadian Journal of Forest Research, 1999, 29(7): 1039-1046, 10.1139/x99-048

ABSTRACT

A slash pine (Pinus elliottii Engelm. var elliottii) study was established to determine the "optimum" seedling size for use on a flatwoods site in the Coastal Plain physiographic province of Georgia, U.S.A. The optimum seedling is defined as the ideotype that will minimize overall reforestation costs while achieving established goals for initial survival and growth. Initial survival and fourth-year performance were examined in relation to (i) method of site preparation, (ii) herbicide application, and (iii) seedling class (based on root-collar diameter) and to associated establishment costs. Seedling class greatly influenced survival with large-diameter classes (8.5-11.5 mm) exhibiting the best survival (87-99%). Seedlings with 4.5-mm diameters averaged 75% survival. A second bedding pass (double bedding) reduced grasses and woody shrubs, and the herbicide imazapyr reduced grasses and herbaceous broadleaf weeds. Neither treatment improved pine survival. Use of 9.5 to 11.5-mm seedlings (without double bedding) produced larger trees 4 years after planting than 4.5-mm seedlings with double bedding. A simple cost analysis indicated the optimum seedling would be considerably larger (9.5-11.5 mm) in diameter than the "target" seedling (4.5 mm) typically produced at slash pine nurseries. For each dollar invested in establishment, planting the optimum pine seedling on this site resulted in greater gains in early survival and growth than either double bedding or use of imazapyr.