Ecological Archives E086-024-A3

Katherine L. Gross, Gary G. Mittelbach, and Heather L. Reynolds. 2005. Grassland invasibility and diversity: responses to nutrients, seed input, and disturbance. Ecology 86:476–486.

Appendix C. A table showing summary of GLM results.

TABLE C1.  A summary of GLM results for treatment effects on species richness (SR) in all years, seedling recruitment (2000 only), and community production (cover in June and August in 2000, aboveground biomass in 2001 and 2002) in response to reduction of vegetative cover (R), fertilizer (F) and seed addition (S).

 Effect

Species per plot

Seedlings 2000

Adult cover (C) or Biomass (B)

 

2000

2001

2002

Numbers

Species

Jun00
(C)

Aug00
(C)

2001
(B)

2002
(B)

R

ns

***

*

***

**

ns

**

ns

**

S

***

***

***

***

***

ns

ns

(*)

ns

F

*

ns

*

ns

ns

***

***

***

***

R × S

**

ns

ns

**

ns

ns

ns

*

ns

R × F

ns

ns

ns

ns

ns

(*)

ns

ns

ns

S × F

ns

ns

ns

ns

ns

ns

ns

ns

ns

R × S × F

*

ns

*

ns

ns

ns

ns

ns

ns

   Notes: Data were log-transformed to meet assumptions of normality and homogeneity of variance. The model, degrees of freedom, and error terms used to test for main effects and interactions are given in Appendix A. Significance levels of F tests are indicated by:  (*)<0.1, but >0.05; * <0.05; **<0.01, *** <0.001; ns = not significant, P > 0. 1.



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