| ITD | Intra-twins difference |
| mean ITDx | the mean ITD values of genus X for each of the 133 genera |
| MD | the mean of ITD values of 28 pairs for all 133 genera |
| ITND | Intra-twins nutrient difference |
| ITD | Intra-twins difference |
| mean ITDx | the mean ITD values of genus X for each of the 133 genera |
| MD | the mean of ITD values of 28 pairs for all 133 genera |
| ITND | Intra-twins nutrient difference |