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An Overview of the Plantation Management Research Cooperative (PMRC) 1975-2003. Barry D. Shiver Director. Creation of the PMRC. Began as an attempt to develop better management methods for plantations Originally begun in flatwoods of GA and FLA since plantations were older there
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An Overview of the Plantation Management Research Cooperative(PMRC)1975-2003 Barry D. Shiver Director
Creation of the PMRC • Began as an attempt to develop better management methods for plantations • Originally begun in flatwoods of GA and FLA since plantations were older there • UGA School of Forest Resources hired students to measure growth and yield plots in summer 1975 • First 5 year MOA 1976-1980
Brunswick Pulp Land Company Continental Can Container Corporation Gilman Paper Company Hudson Pulp & Paper ITT Rayonier Owens Illinois St. Regis St. Joe Paper Company Union Camp Original Ten Members:
Objectives: • Improve stand level management through use of well designed, statistically sound silvicultural studies • Emphasis was on regional importance and therefore replication was minimized at site level • Improve forest level management through development of better growth and yield models to use in harvest scheduling • Models would incorporate findings of silvicultural studies
Replication • Our ideas on replication at a location are different from those at other institutions who base their ideas on traditional Ag experimental designs • There is much more variation across our landscapes than within our stands so we want to capture as much of that variation as possible
Replication • We are not so concerned with making the right decision within the stand where we have an experiment • We are more concerned with having enough replication (# of installations) across the landscape to confidently make decisions on differences regionally • There are valid reasons for replication at a site for some objectives, but management decisions across the landscape is not one of them
Slash Pine Growth and Yield • Began with the 1975 data from several hundred growth and yield plots • Diameter distribution models based on Weibull • In 1976 the plots were revisited and trees were cut and sectioned • Weight, Volume, and Taper Equations • Site index equations from stem analysis data • Result was a yield system for site prepared plantations
Cronartium Study • First PMRC designed study • In 1976 student crews installed about 200 plots in stands across a gradient of ages, site qualities, and infection levels • Location of cronartium cankers along with their size, shape, etc. were noted on each infected tree plus dbh, ht, crown class, etc. • Plots were remeasured every 3 years until the study was terminated
Cronartium Study • Mortality functions with fusiform rust infection as a variable were developed • Effect of cronartium on individual tree growth was modeled
Loblolly Growth and Yield • Some loblolly plots were measured in 1975 though most plantations were too young • In 1977 PMRC student crews measured several hundred loblolly plots in the Carolina’s and felled trees as they went to obtain a dataset similar to the slash dataset • Loblolly volume, weight, taper, diameter distribution and site index models were developed
Competing Vegetation Study • In 1977 the 42 slash pine competing vegetation study installations were established • Paired plots to evaluate effect of understory vegetation on 10-12 year old slash pine • Study was measured every 2 years for over 14 years • Documented the yield reduction from understory competing vegetation
Slash Pine Site Preparation Study • Study to evaluate effects of mechanical site preparation on slash pine growth and yield • Initiated in 1978 • Included 4 complete vegetation control plots and fertilization on all treatments except check • This study is still yielding valuable information today • Included one treatment to duplicate previous treatment
Thinning Studies • Union Camp and St. Regis donated a large set of remeasured studies 12-17 years old that had been designed as a thinning study • The design called for unthinned plots at different densities and larger plots that were to be thinned to the number remaining on the unthinned plots • PMRC student crews thinned and measured the plots in 1978
Thinning Studies • The unthinned thinning plots have been used to develop mortality functions • The thinned plots were used to develop thinning responses for growth and yield models • Our thinned models are based on an unthinned counterpart • This is a useful response model because it allows us to develop thinning models from unthinned stands and plots
Species Comparison • Slash and loblolly were planted side by side on 160 locations across 8 soil groups • Objective was to determine where loblolly should be planted and where slash should be planted • Half installed in 1979 and half in 1980 • Loblolly was as productive as slash on all sites and was more productive on several sites • Study was remeasured through age 20 Study has now been terminated
Remeasurement • In 1980 both the slash and loblolly growth and yield plots were remeasured • Allowed for development of • Mortality functions • Basal area projection equations • Height-Age curves based on remeasured rather than stem analysis data
New MOA • As part of the new 5 year MOA a new geographic subgroup was added – the SAGS (South Atlantic Gulf Slope) group was added • Many companies operated in both areas • Emphasis for this 5 year period was on maintaining and measuring existing studies in flatwoods and beginning new studies in SAGS region
SAGS studies • SAGS region growth and yield plots including felled trees for volume, weight, and taper determination • In 1984 a SAGS version of the competing vegetation study was established in loblolly stands • Loblolly was found to respond even more than slash pine to removal of understory vegetation
SAGS studies • In 1986 a loblolly pine site preparation study with 28 locations was established • Objective was to quantify the effect of differing site preparation treatments on survival, growth and yield • This study included a complete vegetation control plot, but no fertilization • Some treatments mirrored the operational treatments of the day very well • The study was fertilized at age 12 and is ongoing
Improved Planting Stock/Vegetation Control Studies • Otherwise known as Herb-Gen Studies • Loblolly established in 1986 • Objective was to evaluate effect of improved genetic stock in block plantings and to determine the interaction of improved stock and vegetation control treatments
Herb Gen • Loblolly is two studies – one for coastal plain and one for piedmont • Different families involved and completely separate analysis • Genetics in study is for rogued first generation orchards • No longer planting this, but the type of response we get helps us model newer genetics with information from progeny tests (additive response) • We want to evaluate the type of response over a rotation length
Herb Gen • Response for the herb gen plots has been very consistent across geographic regions for loblolly and even for slash pine • Get a response for improved genetics and a response for vegetation control and the two repsonses are additive • Get a reduction in cronartium infection for both species even with faster growth
A Mid 80’s Change • In the mid 1980’s the University hired permanent staff to work on PMRC and other long term research projects • Having permanent staff to visit research installations for maintenance and measurement insured better consistency from company to company • It also facilitated data turnaround from measurement to analysis to report
Permanent Field Staff • We now have 6 workers who maintain and measure PMRC, CAPPS, and other research plots for the University • The professionalism exhibited by these crews has allowed PMRC to maintain plot numbers that we not would otherwise have been able to maintain
Culture Density Studies • Realized that our density studies probably provided incorrect answers for intensively managed stands • One location spacing study at B.F. Grant indicated our ideas on density were incorrect • Established in SAGS region in 1995 and in Coastal Plain in 1996 • 2 levels of management and 6 densities
Culture Density Studies • Several coastal plain sites have slash and loblolly at 300, 900, and 1500 tpa so there is opportunity for species comparison at 2 levels of management • Through age 6 some loblolly trees are growing at 7 ft/yr and the average is over 5 ft • Intensive culture impacts height growth on loblolly more so than on slash pine • Basal areas are 140-175 ft2/ac at age 6 for higher densities (>1200 tpa)
Intensively Managed loblolly pine - 6 yrs old, 300 tpa planted
Intensive lob – 6 yrs; 600 tpa planted Intensive lob – 6 yrs; 900 tpa planted Intensive lob – 6 yrs; 1200 tpa planted
Growth and Yield Models • Much more sophisticated than earlier efforts • Now we combine growth and yield plots with designed study results • We have models for first generation plantations and second generation plantations • We have the ability to estimate effects of multiple silvicultural treatments (hardwood control, herbaceous weed control, fertilization)
Slash and Loblolly PineGrowth and Yield Systems: • Whole stand system with merchandising component • Diameter distribution • Generalized stand table projection • Response models for intensive management treatments
PMRC Studies as Research Platforms • Throughout the history of the PMRC the study sites have been used for research purposes for which they were not originally intended when that could be accomplished without compromising the original intent • Slash site preparation studies have been used to evaluate nutrient cycling and wood quality
PMRC Studies as Research Platforms • The herb gen plots have been used by the wood quality consortium as have the species comparison plots • The intensive culture/density studies have been used for a variety of leaf area, biomass and physiology studies • Larger scale studies like these have been submitted for funding to national agencies
PMRC Studies as Research Platforms • The intensive culture/density studies are also the research platform for the branch modeling study recently funded (partially) by TIP3 • So, in addition to the good management and modeling information PMRC gets, these plots serve as a basis for funding from other agencies (Agenda 2020,NRI, TIP3, etc.)
Conclusions • So, after 28 years, the PMRC and other cooperatives have served the forestry community well • They have done so by taking the long term view. If coops do not maintain long term studies, who will? • As you and your company representatives ponder the future of forestry research, take a long term view
Conclusions • Many of the useful results that govern our current silvicultural and management systems, the underlying study, even if it was funded outside a cooperative, was a coop study • For those who never knew some of the old studies established by PMRC, come up with some new ways of using that old data and let us know!