Ten Ways That Weed Evolution Defies Human Management Efforts Amidst a Changing Climate

Abstract

The ability of weeds to evolve is key to their success, and the relationship between weeds and humans is marked by co-evolution going back to the agricultural revolution, with weeds evolving to counter human management actions. In recent years, climate change has emerged as yet another selection pressure imposed on weeds by humans, and weeds are likewise very capable of adapting to this latest stress of human origin. This review summarizes 10 ways this adaptation occurs: (1) general-purpose genotypes, (2) life history strategies, (3) ability to evolve rapidly, (4) epigenetic capacity, (5) hybridization, (6) herbicide resistance, (7) herbicide tolerance, (8) cropping systems vulnerability, (9) co-evolution of weeds with human management, and (10) the ability of weeds to ride the climate storm humans have generated. As pioneer species ecologically, these 10 ways enable weeds to adapt to the numerous impacts of climate change, including warming temperatures, elevated CO2, frequent droughts and extreme weather events. We conclude that although these 10 ways present formidable challenges for weed management, the novelty arising from weed evolution could be used creatively to prospect for genetic material to be used in crop improvement, and to develop a more holistic means of managing agroecosystems.

Evolution of increased competitive ability may explain dominance of introduced species in ruderal communities

“…Despite this limitation, our study suggests that, as compared to ancestral populations, non‐native populations of C. solstitialis possess enhanced protection against generalist herbivores encountered in the Caldenal (Hierro et al, 2013, 2017). Increased growth, competitive abilities, and defense may result in a combination powerful enough to make C. solstitialis an ideal weed (Baker, 1965; Clements & Jones, 2021) in that system. Centaurea solstitialis may thus be part of the select group of species shown to be capable of growing faster, defending better, and suppressing neighbors more strongly in non‐native than native ranges (Beaton et al, 2011; Kumschick et al, 2013; Ridenour et al, 2008).…”

“…In sum, our assessment of the EICA hypothesis offers three main conclusions. First, evolutionary change between ancestral and non‐native populations is a widespread process (Clements & Jones, 2021; Lortie & Hierro, 2022). Second, that change does not generally proceed through trading growth for shifted defense.…”

The role of intraspecific crop-weed hybridization in the evolution of weediness and invasiveness: cultivated and weedy radish (Raphanus sativusL.) as a case study

“…The copyright holder for this preprint this version posted March 2, 2023. ; https://doi.org/10.1101/2023.03.01.530677 doi: bioRxiv preprint potential to increase weediness and invasiveness in a wide range of environmental conditions (e.g., both inside and outside the agricultural environment), and could increase the chances of success when hybrids invade new environments or are exposed to environmental changes as a result of ongoing climate change (Hovick et al, 2012;Clements and Jones, 2021). However, our inference should be studied by further by evaluating the effect of crop-weed hybridization across a greater diversity of locations in order to assess the generality of these results.…”

Detection of Palmer amaranth (Amaranthus palmeri) and large crabgrass (Digitaria sanguinalis) with in situ hyperspectral remote sensing. I. Effects of weed density and soybean presence

“…With the introduction of herbicide-resistant crops and the lack of rotation of herbicide chemistries, the agricultural ecosystem in production fields is changing due to increasing anthropogenic selection pressures on weed populations (Clements and Jones 2021;Owen 2008). This pressure over time has resulted in the selection of weed biotypes that are resistant to herbicides.…”