Regionwide Trials

The foundation of our research continues to be field studies examining the effects of silvicultural treatments applied during stand establishment (e.g., soil tillage, vegetation management, fertilization) and in established stands (e.g., thinning, fertilization, woody vegetation control) on stand growth and nutrition.

Since 1970, FPC members have established over 350 installations of 28 “regionwide” studies in the southeast US, Brazil, Uruguay, Venezuela, Argentina, Chile, and Colombia. Studies are focused on a few important questions that are more effectively answered by members cooperating rather than competing. Most studies examine several silvicultural treatments, providing an opportunity to better understand interactions among treatments. All studies include multiple installations across a range of soil/site types where treatments are replicated at least twice on each site. Data from these studies provide the basis for estimating responses to silvicultural treatments, developing prescription guidelines, and parameterizing growth models.

Use the Regionwide Catalog to access documents and data corresponding to each regionwide study.

Active Regionwide Trials

RW28

Trials: 18

Species: P. taeda

Location: United States

Study Design: Phosphorous Carryover from RW18

RW25

Trials: 8

Species: P. taeda, E. benthamii, E. grandis, E. urograndis

Location: Brazil, Chile, and Colombia

Study Design: Nutrient Omission Study

RW19

Trials: 9

Species: P. taeda

Location: Argentina, United States, and Uruguay

Study Design: Thinning x Fertilization Response

LARW2

Trials: 6

Species: P. radiata, E. grandis, E. grandis x camaldulensis, P. taeda

Location: Argentina and Chile

Study Design: GxExS, Optimization of Value at Harvest Age

RW25

Species: Eucalyptus spp.

Location: Brazil

Study Design: Nutrient omission (Micro and Micro) in Eucalyptus spp.

RW21

Species: Eucalyptus spp.

Location: Colombia and Venezuela

Study Design: Twin-plot network in eucalyptus plantations

RW15

Species: P. taeda, P. radiata

Location: Chile and United States

Study Design: Combinations of N, P, K, and micronutrients in established stands

RW11

Species: P. taeda

Location: United States

Study Design: Thinning intensity and nitrogen application rate study

RW5

Species: P. taeda

Location: United States

Study Design: Thinning x Nitrogen fertilization

RW2

Species: P. taeda

Location: United States

Study Design: Response of loblolly pine to juvenile Nitrogen fertilization

RW27

Trials: 2

Species: E. globulus x nitens

Location: Chile

Study Design: Position and Depth of Fertilizer Application at Planting

RW23

Trials: 5

Species: E. grandis, P. taeda

Location: Brazil and Colombia

Study Design: Intensity and Duration of Vegetation Control

RW7

Trials: 12

Species: P. taeda, P. radiata, P. maximinoi

Location: Argentina, Brazil, and Chile

Study Design: Site Prep x Fertilization x Vegetation Control

Special Study

Trials: 6

Species: P. taeda, E. grandis, Gmelina arborea

Location: Colombia and United States

Study Design: Calcium Application Source and Rate Study

RW1

Species: P. taeda

Location: United States

Study Design: Mid– to Late-Rotation Fertilization

RW20

Trials: 3

Species: P. taeda

Location: Brazil and United States

Study Design: Genetics x Silviculture x Spacing

LARW1

Trials: 3

Species: P. radiata

Location: Chile

Study Design: Long-term Sustainability Study

Completed Regionwide Trials

RW24

Species: Eucalyptus spp.

Location: United States

Study Design: Cold hardy Eucalyptus in the Southeastern United States

RW17

Species: P. taeda, P. elliottii

Location: United States

Study Design: Fertilization x vegetation control factorial at midrotation

RW14

Species: P. taeda

Location: United States

Study Design: Control, 45N, 50P, 100K combinations, and delay and repeat fertilization at establishment

RW9

Species: P. taeda

Location: United States

Study Design: Nitrogen fertilization treatments after thinning

RW4

Species: P. taeda

Location: United States

Study Design: Effectiveness of different rates of Nitrogen

RW26

Trials: 1

Species: E. urograndis

Location: Colombia

Study Design: Dose and Efficiency of Phosphorous Fertilization at Establishment

RW22:

Species: Pinus spp.

Location: United States

Study Design: Twin-plot network in pine plantations

RW16

Species: P. taeda

Location: United States

Study Design: Surface x subsurface tillage factorial at establishment

RW13

Species: P. taeda, P. radiata

Location: Chile and United States

Study Design: Midrotation fertilization with factorial combinations of N and P

RW7

Species: E. benthamii

Location: United States

Study Design: Site Prep x Fertilization x Vegetation Control

RW3

Species: P. taeda

Location: United States

Study Design: Comparison of ammonium nitrate and urea as Nitrogen sources