
Hello I am analysing aboveground biomass data from revegetation testplots which I constructed in a split-plot design using the function lme. For the experiment, the three factors are amelioration (2 levels), fertilizer (2 levels) and treatment (7 levels). Each testplot (block) has a singlereplicate of each treatment (total of 8 testplots). The blocks were constructed of topsoil. Each block was divided in two subplots in which half were ameliorated the other half was not (amelioration - yes or no). Each subplot was divided again into two subplots (fertilizer - yes or no). Then for eachfertilizer subplot, the area was divided into 7 seeding treatments (treatments). I have transformed my data to meet model assumptions and simplified my model using stepwise elimination. Here is my minimal model: fm13<- lme(sqrt(abovegroundbiomass.m.2)~amelioration+fertilizer+treatment,random=~1|block,
method="ML",na.action = na.omit) Here is a summary output: summary(fm13)$tTable
                                            Value          Std.Error     DF      t-value             p-value
(Intercept)                         1.6196612     0.9058574    100   1.7879869     7.680688e-02
ameliorationyes                  1.0155789     0.5970789    100   1.7009125     9.206718e-02
fertilizeryes                         4.3153841    0.5970789    100   7.2274943     9.985161e-11
treatmentelymgla ecovar      5.0125584    1.1170323    100   4.4873891     1.931291e-05
treatmentelymgla local         2.7699072    1.1170323    100   2.4797020    1.482059e-02
treatmentfestsax ecovar      0.6953266     1.1170323    100   0.6224768     5.350453e-01
treatmentlupiarc local          1.1391840    1.1170323    100    1.0198309     3.102696e-01
treatmentnativemix ecovar   2.1091683    1.1170323    100    1.8881892    6.189917e-02
treatmentnativemix local      3.2103166    1.1170323    100    2.8739694    4.951797e-03 I would like to obtain the back-transformed estimates but I cannot seem to find the a way to do this. I have a copy of Crawley (The R Book) but could not find instructions on how to back-transform in lme. I have also look for a copy of Zuur (Mixed Effects Models and Extensions in Ecology with R) but cannot seem to obtain a copy.  Any guidance in how to backtranform these estimates would be greatly appreciated. Thanks. Allan CarsonGraduate StudentUniversity of Northern British Columbia


 



 		 	   		  
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