# Ground-Active Arthropod Diversity Under Energycane and Biomass Sorghum Production

## TL;DR

This study compares the ground-active arthropod diversity in energycane, biomass sorghum, and conventional crops in the southeastern US, finding no significant differences in diversity.

## Contribution

The study provides new insights into the biodiversity impacts of cellulosic energy crops, specifically energycane and biomass sorghum.

## Key findings

- Arthropod abundance was highest in conventional crops compared to biomass sorghum and energycane.
- Order-based arthropod richness was slightly higher in biomass sorghum than in energycane.
- There was no significant difference in order-based Shannon and Simpson diversity among the three crop types.

## Abstract

Energycane and biomass sorghum are two of the most promising cellulosic energy crops in the southeastern US. Research on both crops has focused mainly on biomass production, and there is a lack of information on their ability to promote biodiversity and ecosystem services (i.e., direct and indirect benefits to human society). This paper presents results from a comprehensive study on arthropod diversity in seven sites across five states in the southeastern US (Florida, Georgia, Louisiana, Mississippi, and Texas). Traps were deployed four times to capture ground-dwelling arthropods in energycane, biomass sorghum, and a local reference conventional crop. Daily catches on the number of individuals per trap were 4.9, 3.7, and 2.6 for conventional crops, biomass sorghum, and energycane, respectively. Order-based arthropod richness values were 5.3, 5.2, and 4.8 for biomass sorghum, conventional crops, and energycane, respectively. The results from this study indicate a lack of a significant difference in order-based arthropod diversity between these crops.

Energycane and biomass sorghum are two of the most promising cellulosic energy crops in the southeastern US. Research on these two energy crops has focused mainly on biomass production, and there is a lack of knowledge on their ability to promote biodiversity and ecosystem services. This paper presents results from a comprehensive study on ground-active arthropod diversity in seven sites across five states in the southeastern US (Florida, Georgia, Louisiana, Mississippi, and Texas). Pitfall traps were deployed four times during each crop season for energycane, biomass sorghum, and a local reference conventional crop from 2020 to 2022. Arthropod abundance (individuals/(trap × day)) values were 4.9 ± 0.46, 3.7 ± 0.18, and 2.6 ± 0.16 (mean ± stderr) for conventional crops, biomass sorghum, and energycane, respectively, with a significant difference found only between conventional crops and energycane. Individuals were identified to arthropod orders, and Hill’s diversity indices were calculated based on the number of individuals in each arthropod order instead of the number of individuals in each arthropod species. Order-based arthropod richness values were 5.3, 5.2, and 4.8 for biomass sorghum, conventional crops, and energycane, with significant difference found only between biomass sorghum and energycane. There was no significant difference in the order-based Shannon diversity and Simpson diversity between the three crop types. The effective number of arthropod orders for the two energy crops decreased from 5.0 to 3.4 to 2.9 with increasing order of diversity from arthropod richness to Shannon diversity to Simpson diversity. The explained variability by environmental factors also decreased with increasing Hill’s order of diversity. The results from this study indicate no significant advantage in order-based arthropod diversity in growing biomass sorghum and energycane. This research fills a critical knowledge gap in understanding the impacts of cellulosic energy crop production on biodiversity and ecosystem services.