head(comu_2012_dt)

'# A tibble: 6 x 5
# Groups:   block [2]
         block   treatment Total_sp Total_abundance  year
        <fctr>      <fctr>    <int>           <int> <dbl>
1   Black Rock   1 Control       88             124  2012
2   Black Rock    2 Light       113             191  2012
3   Black Rock 3 Moderate        69             115  2012
4   Black Rock 4 Intensive       98             175  2012
5 Forest Grove   1 Control       37              54  2012
6 Forest Grove    2 Light        83             142  2012


head(comu_2013_dt)

# A tibble: 6 x 5
# Groups:   block [2]
         block   treatment Total_sp Total_abundance  year
        <fctr>      <fctr>    <int>           <int> <dbl>
1   Black Rock   1 Control       72             114  2013
2   Black Rock    2 Light       107             190  2013
3   Black Rock 3 Moderate        34              50  2013
4   Black Rock 4 Intensive       51              86  2013
5 Forest Grove   1 Control      109             256  2013
6 Forest Grove    2 Light        86             226  2013