Presentation on theme: "Vector Analysis: Does it really predict growth response? Mariann Johnston, SUNY-ESF Ranger School."— Presentation transcript:
Vector Analysis: Does it really predict growth response? Mariann Johnston, SUNY-ESF Ranger School
Shoestring Satellite Experiment: The Adirondack Screening Trials Individual tree fertilization trials James F. Dubuar Memorial Forest, Adirondack Park 2 Species Sugar maple (dom/codom, ~30 cm dbh) Am. beech (intermediate, ~10 cm dbh) 6 Treatments screened
Shoestring Satellite Experiment: The Treatments Control N1: 30 N (urea) N1P1: 30 N + 30 P (MAP + urea) N2: 200 N N2P2: 200 N P N2P2KB: 200 N P K + 3 B One-time application Shoestring Project Prelim
Vector Analysis Foliar diagnostic technique Predicts nutrient deficiencies Assumes that foliage response is a predictor of tree yield response Did it work?
Sugar Maple Vector analysis said: Response to N2P2KB will occur N, P, K were deficient
Sugar Maple Growth Response No significant differences between treatments
American Beech Vector analysis said: No growth response to any fertilization treatment will occur
Beech Growth Response p-values:
Conclusions Did vector analysis predict growth response? No, not really (2-yr BA) But... Foliage-damaging spring freeze occurred at time of fertilization Height, volume growth were not analyzed Continue monitoring for future responses
Conclusions Beech responded to fertilization! Intermediate crown class, understory cohort Is beech a nutrient hog? What are the ecological implications?
Sugar Maple Growth Mean dbh Yr 0: 34.6 cm Mean dbh Yr 2: 35.0 cm Average BA response of 2.4% No differences between treatments were detected Predicted growth responses not apparent in diameter response
Beech Growth Mean dbh Yr 0: 9.9 cm Mean dbh Yr 2: 10.7 cm Average BA response of 18.1% All treatments showed significant (p < 0.05) growth compared to control except for N2 (200 kg N)