Functional Traits Plasticity of the Invasive Herb Argemone ochroleuca Sweet in Different Arid Habitats

Abstract

Understanding the strategies and mechanisms of invasive species could guide their control and management especially in arid ecosystems. This study compares the vegetative and reproductive functional traits of the invasive Mexican poppy (Argemone ochroleuca), in seven habitat types, in southwestern Saudi Arabia. The results showed that the aboveground phenological attributes such as plant height, leaf area, and leaf dry mass attained the highest values in the wadi channels, whereas these attributes attained the lowest values in the mountain ranges. Maximum specific leaf area, root parameters, and all reproductive traits were recorded in the abandoned fields. In contrast to all other habitats, populations from abandoned fields had a greater investment of resources in belowground structures, while the population growing in the wadi channels and mountain ranges habitat allocated more energy to vegetative parts. The plasticity in vegetative and reproductive resource allocation in A. ochroleuca is an important mechanism in determining its colonizing ability in different habitat types and expanding the distribution range. The present data of the functional traits of A. ochroleuca agree with the resource fluctuation hypothesis, where the plant flourished in the abandoned fields that attained the highest values of organic matter and nutrients. Therefore, the restoration of these disturbed habitats could improve the resistance toward invasion by this noxious weed.

Impacts of Anthropogenic Disturbance on Vegetation Dynamics: A Case Study of Wadi Hagul, Eastern Desert, Egypt

“…The introduction of invasive and alien species into natural habitats represents a threat to existing species. Assaeed et al [ 86 ] indicated that invasive and exotic plants may pose a threat to natural resources and biodiversity, especially in arid habitats. Successful invaders often exhibit great degrees of adaptability, allowing them to thrive in a variety of environments [ 87 , 88 ].…”

Trait-Environment Relationships Reveal the Success of Alien Plants Invasiveness in an Urbanized Landscape

“…This hypothesis speculates that resource-demanding alien species are likely to enter high-resource urban habitats correlated with high human-made pressures. These pressures are supposed to increase the content of soil organic matter and nutrients [ 56 ] that can facilitate alien invasiveness. By contrast, native species show homogeneity in their associations with the environment in urban and non-urban habitats, indicating their conservative responses towards urbanization.…”

“…According to recent invasion research, alien populations may accomplish rapid-growth by reallocating below-ground and above-ground biomass, which could be linked to resources fluctuation [ 58 , 59 , 60 ]. For example, a comparative study by [ 56 ] found that the alien plant species Argemone ochroleuca optimized biomass allocation and maximized resource utilization in an urbanized habitat [ 61 ] in a way that maximized fitness and growth [ 62 , 63 ]. This shift in biomass allocation suggests that intraspecific variation and potential plasticity in plant functional traits can be considered as an adaptive strategy to changes in environmental conditions [ 64 , 65 ].…”