J Plant Ecol ›› 2018, Vol. 11 ›› Issue (3): 465-474.

• Research Articles •

### Human occupation explains species invasion better than biotic stability: evaluating Artocarpus heterophyllus Lam. (Moraceae) (jackfruit) invasion in the Neotropics

Guilherme de Oliveira*

1. Laboratório de Biogeografia da Conservação, Universidade Federal do Recõncavo da Bahia (UFRB), Centro de Ciências Agrárias, Ambientais e Biológicas (CCAAB), Setor de Ciências Biológicas, Rua Rui Barbosa 710, Centro 44380-000, Cruz das Almas, Bahia, Brasil
• Received:2016-11-04 Accepted:2017-03-06 Published:2018-03-06
• Contact: de Oliveira, Guilherme

Abstract: Aims Biological invasions are recognized to put native species in risk of extinction. In this study, I tested whether the invasion of Artocarpus heterophyllus Lam. (Moraceae; jackfruit) in the Neotropics was explained by its biotic stability, an intrinsic force, or by human occupation, an extrinsic force.
Methods I used an ensemble framework combining 12 ecological niche models (ENMs) and 4 atmosphere-ocean general circulation models. ENMs were constructed for the pre-industrial time period in the Indo-Malaya biogeographic region, the native habitat of A. heterophyllus, and were then projected to past (last glacial maximum, 21000 years ago and mid-Holocene, 6000 years ago) and future (end of century, 2080) periods. The ENMs were used to establish the biotic stability of A. heterophyllus in areas where it was predicted to be present concomitantly within these four time periods. This biotic stability was projected onto the Neotropics, and then I used a null model and logistic regression to test what the main driver of A. heterophyllus invasion.
Important findings In general, the presence of A. heterophyllus in the Neotropics was not explained by biotic stability, tested by the null model. However, human occupation explained much of its presence in the invaded habitat, once all standardized coefficients related to this driver was significant positive in the logistic regression. Based on these results, humans sustained the presence of A. heterophyllus in the Neotropics, probably because of the additive influences of propagule pressure and habitat disturbance. Thus, the recommendation is that the cultivation of A. heterophyllus in the Neotropics must be regulated and supervised, primarily near reserve areas.

Aims Biological invasions are recognized to put native species in risk of extinction. In this study, I tested whether the invasion of Artocarpus heterophyllus Lam. (Moraceae; jackfruit) in the Neotropics was explained by its biotic stability, an intrinsic force, or by human occupation, an extrinsic force.
Methods I used an ensemble framework combining 12 ecological niche models (ENMs) and 4 atmosphere-ocean general circulation models. ENMs were constructed for the pre-industrial time period in the Indo-Malaya biogeographic region, the native habitat of A. heterophyllus, and were then projected to past (last glacial maximum, 21000 years ago and mid-Holocene, 6000 years ago) and future (end of century, 2080) periods. The ENMs were used to establish the biotic stability of A. heterophyllus in areas where it was predicted to be present concomitantly within these four time periods. This biotic stability was projected onto the Neotropics, and then I used a null model and logistic regression to test what the main driver of A. heterophyllus invasion.
Important findings In general, the presence of A. heterophyllus in the Neotropics was not explained by biotic stability, tested by the null model. However, human occupation explained much of its presence in the invaded habitat, once all standardized coefficients related to this driver was significant positive in the logistic regression. Based on these results, humans sustained the presence of A. heterophyllus in the Neotropics, probably because of the additive influences of propagule pressure and habitat disturbance. Thus, the recommendation is that the cultivation of A. heterophyllus in the Neotropics must be regulated and supervised, primarily near reserve areas.