## 3 Results and Discussion
### Arthropods and Plants Diversity
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Family/Species**} & \multicolumn{4}{c}{**IVI**} \\ \cline{2-5}  & **June** & **July** & **August** & **September** \\ \hline Amaranthaceae & & & & \\ _Alternanthera tenella_ Colla & 0 & 40.04 & 22.54 & 9.19 \\ \hline Asteraceae & & & & \\ _Artemisia abstinthium_ L. & 0 & 0 & 0.68 & 0 \\ _Centratherun punctatum_ Cass. & 0 & 6.73 & 11.91 & 0 \\ _Lipidaploa colonaaster_ (Wild. [PERSON].) & 0 & 13.14 & 8.5 & 18.09 \\ _Lourteigia ballateofolia_ ([PERSON]) [PERSON] and [PERSON]. & 0 & 36.23 & 26.19 & 9.85 \\ _Tridrax procumbers_ L. & 0 & 6.23 & 0 & 0 \\ \hline Commelinaceae & & & & \\ _Commelina eercla_ L. & 100 & 7.16 & 7.45 & 0 \\ \hline Fabaceae & & & & \\ _Calopogonium_ sp. & 0 & 9.67 & 6.97 & 6.56 \\ _Chamancrista rotundifolia_ Moench & 0 & 0 & 0 & 20.15 \\ _Mimosa_ sp. & 0 & 3.32 & 5.75 & 2.71 \\ \hline Malvaceae & & & & \\ _Sida coridifolia_ L. & 0 & 9.98 & 5.72 & 5.62 \\ _Paconia cancellata_ [PERSON][PERSON]. & 0 & 2.38 & 0 & 11.67 \\ _Sidastrum panicultum_ [PERSON][PERSON] & 0 & 0 & 3.89 & 0 \\ _Sida_ sp. & 0 & 0 & 1.07 & 0 \\ \hline Poaceae & & & & \\ Specie 1 & 0 & 1.43 & 0 & 0 \\ \hline Rubiaceae & & & & \\ _Borreria verticlata_ [PERSON]. & 0 & 0 & 1.95 & 0 \\ \hline Solanaceae & & & & \\ _Solanum lyocarpum_ A.St.-Hil. & 0 & 3.74 & 1.07 & 0 \\ _Solanum agarium_ [PERSON]. & 0 & 2.56 & 0 & 0 \\ \hline Unidentified & & & & \\ Specie 2 & 0 & 0 & 0 & 0.96 \\ Specie 3 & 0 & 0 & 0 & 1.05 \\ Specie 4 & 0 & 0 & 1.07 & 0 \\ Specie 5 & 0 & 0 & 3.04 & 0 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Plant importance value index (IVI) collected from June to September 2015 in a sisal crop. sites sampled in September and were associated with the arthropod 112 (larvae). The other arthropods showed shorter projections, indicating that they occurred during most of the sample months or were related to several plants. The vegetation can influence arthropods through different processes. For example, foliar herbivory may indirectly affect the soil biota and affect below-ground processes through the effects on plants. These effects may manifest either as changes in plant C allocation and root exudation or as in root biomass and morphology, altering plant litter quality [37]. The decomposers of the plant litter, such as Collembola, could be affected by changes produced in the litter by P1, P6, P2, and P20 and the higher precipitation during those months. Moreover, the presence of Collembola can modify the chemical composition of the soil affecting differently different species of plants [38]. Therefore, the high amount of Collembola during July and August could affect the soil's chemical composition and, consequently, the results found in September. [PERSON] et al. [39] investigated the relation among Collembola species and abundance to manipulation of the plant species richness and the plant functional groups number. Their results suggested that the presence of certain plant species and functional groups may be more important for the collembolan community structure than the diversity of plant species and functional groups per se, which is in line with our results. Contrastingly, the other arthropods might be more related to the diversity of plants. Further studies are needed to clarify this hypothesis. Figure 3: RDA triplot showing the relationships between the Hellinger-transformed abundance of arthropods (response variable) (\(\bullet\)), the IVI of plant species (explanatory variables) (\(\blacksquare\)), and sample points in June, July, August, and September (\(\bigcirc\), \(\square\), \(+\), \(\Delta\), respectively). The percentage of variance explained by the two first canonical axes (RDA 1 and RDA 2) is indicated between brackets in the axes titles. P1-_Alternanthera tenella_, P6-_Centratherrum punctatum_, P2-_Louteigia ballottiglia_, P7-_Solanum lyococarpum_, unidentified species 2 (P20), P9-_Pavonia cancellata_, P12-_Chuanecrista rotundifolia_.