Weed Population Dynamics under Climatic Change (original) (raw)
Related papers
Frontiers in Plant Science, 2017
Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C 3 and C 4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C 4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C 4 plants. Although CO 2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the cropweed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO 2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an integral role in developing future management programs for future weed threats. This review has presented a comprehensive discussion of the recent research in this area, and has identified key deficiencies which need further research in crop-weed ecosystems to formulate suitable control measures before the real impacts of climate change set in.
Weeds and Weed Management under a Changing Climate
Human activities, including expanded fossil fuel use and deforestation, have caused atmospheric CO 2 to increase significantly from a pre-industrial concentration. Levels are expected to double sometime during this century, even if CO 2 emissions are immediately scaled back. An increase in CO 2 and other greenhouse gases could lead to an increase in global surface temperature. Both of these major climate change factors will affect the growth of plants, through modification of their photosynthetic performance and other physiological changes. As CO 2 rises, C 3 plants will increase their net photosynthesis, growth, and yield compared to C 4 plants. Therefore, higher atmospheric CO 2 is likely to stimulate the yields of most of the world's crops, which are C 3 plants. Many of the most troublesome weeds in agriculture are C 4 plants, and there is a view that the competitive ability of these weeds might be reduced relative to C 3 crops as climate change occurs. However, as 'colonising plants', weeds have many biological traits, including wide ecological amplitudes, which may give them advantages over other plants to exploit more successfully changed environmental conditions. Also, there are a large number of C 3 weeds in the world, which may become more aggressive under elevated CO 2 and warmer conditions. Under changed climatic conditions, it is more than likely that weeds will become more competitive. The outcome will be potentially negative consequences for agricultural productivity across different regions of the globe, negating some of the otherwise beneficial effects of CO 2 'fertilization' of the major world crops. It is also probable that colonising plants will extend their bio-geographical ranges as global environmental changes occur, and weed management in field situations will become more costly and difficult. Humans have no option, but to adapt to effects of elevated CO 2 and warming of the planet, which they exacerbated. However, climate change is not the only factor that will be changing as 21 st century unfolds. Population growth and varying economic and technological changes are likely to affect the environment no less than will climate change. Developed countries, due to technological advancements, appear better adapted to respond to climate change, including the likely increased global impacts of weeds. On the other hand, burdened by population pressure and declining natural resource bases, many developing countries in the tropical and sub-tropical regions will not be so well placed to face climate change and its flow-on effects, such as water and food scarcity. Our adaptive responses need to be based on increased knowledge of how plant communities will respond to climate change. It will require applying more rigorously scientific knowledge to effectively manage man-made or natural ecosystems. Examples of rational approaches include breeding allelopathic crops cultivars and drought-and stressresistant varieties. Increased conservation farming, agro-forestry, and more holistic weed and pest management will also become more important in the future. Humans must also take action to reduce the primary root cause: the high rate of CO 2 emissions, by a variety of approaches. This would involve burning less fossil fuels, eradicating large-scale deforestation occurring in the tropics and preventing reclamation of large wilderness areas for agricultural use. Among the most feasible actions to mitigate the CO 2 build up involve some combination of conserving energy, substituting alternative energy sources (e.g. solar, wind and hydropower) for fossil fuels.
Impact of climate change on weed threat
2019
Natural events and human activities are believed to be contributing to an increase in average global temperatures. This is caused primarily by increase in greenhouse gases. In future decades, when climate change effects are more consistently felt, weed management requirements in agriculture and nonagricultural situations will change. Control of weeds is likely to be more difficult and more expensive under climate change. Some well known invasive species are likely increase their bio-geographical ranges, and other, relatively mild species may become aggressive invaders. Several studies have focused on the impact of climate change on crop productivity, but less attention has been given to the impact on weed management, particularly herbicide efficacy and its subsequent effects on the development of herbicide-resistant weeds. The mitigation of climate change vulnerability can be mitigated by storing carbon in soils which reduces atmospheric levels of carbon. Climate change has severe d...
Climate Change: Influence on Weeds and New Weed Management
NEW DELHI PUBLISHERS, 2021
Weeds are recognized globally as a major constraint to crop production and food security. In recent decades, the extensive use of herbicides in conjunction with genetically modified herbicide resistant crops has aggravated the situation and it is considered as one of the main drivers of biodiversity loss. Global climate change will further make weed management more challenging. Rise in atmospheric CO2, temperature and changes in rainfall patterns would influence C3 and C4 weeds differently. Weed shifts and invasive alien weeds would become more evident, hence, challenging global crop production. New ecological weed management strategies could help in managing weeds under climate change scenarios. New integrated weed management strategies which reduce reliance on herbicides and encourage non-chemical and ecological approaches would be the future of weed management on long term basis. Keywords: Climate Change; CO2; Selection Pressure; Herbicides; Biodiversity Loss; Resistance; Ecological; Allelopathy; Weed; Management; Paradigm; Future
Weeds and Their Responses to Management Efforts in A Changing Climate
Agronomy
Crop production is a constant battle with weeds, in which weeds, generally, are victorious. Therefore, rather than channeling our efforts into the development of a “silver bullet” to control weeds, the focus should be on sustainable weed management in both natural- and agro-ecosystems. However, sustainable weed management can be a challenge in the context of global climate change. Over the past few decades, global climate change, mostly indicated by phenomena such as increased atmospheric temperature and elevated CO2 levels, is evident due to human activities and natural events. These phenomena also affect regional/local climate, resulting in significant influences on the agricultural systems of a particular region. Rising CO2 levels may give comparative advantages to C3 plants through increased photosynthesis, biomass production and yield, compared to C4 plants. Plants with C4 photosynthetic pathways, on the other hand, are likely to benefit more from rising global temperatures tha...
Possible Effects of Climate Change on Weeds in Agriculture
Selçuk tarım ve gıda bilimleri dergisi, 2020
Agricultural activities are responsible for about 20% of the world's growing greenhouse gases. So energy consumption, Plant Production, Animal Husbandry, fertilization, spraying, etc. in particular, CO 2 , CH 4 and N 2 O are responsible for increasing greenhouse gases (Fig. 3) (Houghton 2003; Pathak & Wassmann 2007). Greenhouse gas emissions from carbon-source soils are increasing as a result of improper land use and unconscious and excessive fertilizing and pesticides (Fig. 4) (Lal 2006). The share of major greenhouse gases in global climate change is given in Figure 2.
Crop-weed interactions and their management under climate change: A review
2019
Weeds pose as biggest threat to crop production accounting about 43% yield loss globally. Unchecked human activities such as over-expanded use of fossil fuels and deforestation have resulted in climate change which further worsens the present situation by impacting both crop and weed. Predicted alteration in atmospheric CO2, temperature and frequent extreme events (e.g., droughts and floods) owing to climate change will reduce crop yields by affecting plant growth as well as pest pressure (weed, insect pest and pathogens) and their invasiveness, thus threatening global food security. CO2 fertilization due to rising CO2 level will benefit C3 crops, thus reducing the competitive ability of most of troublesome weeds which are C4 plants. However, weeds are predicted to become more competitive over crops owing its wide genetic diversity, colonising ability and enhanced aggressively of C3 weeds consequently making weed management in field situations costlier and more difficult. Change in ...
2022
Global climate change and its consequences such as rising temperatures, carbon dioxide (CO2) levels, variable rainfall and soil salinity has an impact on weed species, their population dynamics, reproduction and competitive ability; eventually crop productivity. Among these environmental factors, rising CO2 levels will benefit C3 plants, but in the near future, plants with C4 pathways will be benefited more from rising temperatures and changing rainfall patterns around the world. Climate change can alter the weed life cycle, community composition, distribution, phenology and infestation. Over the course of the year, some weed species go extinct while others develop into more noxious invaders and evolve genetic artefacts in response to intensifying climatic and non-climatic selection pressures. Due to unfavourable climatic change, weed species release allelo chemicals along with increase the growth of below ground part such as root or rhizome, particularly in perennial weeds, making the weed more competitive over crops. On the solution side, variations in temperature, CO2 levels and rainfall alter stomatal conductance, cuticle viscosity, transport, uptake, leaf retention duration and herbicide efficacy. Therefore, to adapt and mitigate; it is important to review how climate change can influence the crop-weed interaction, competition, herbicide efficacy and resistance.
Predictive Modelling for Rice Weeds in Climate Change: A Review
Advances in Agricultural and Food Research Journal, 2022
Rice (Oryza sativa L.) is an essential staple food not only for Asians but also for people worldwide. However, weeds in rice fields can cause yield reduction due to their tendency to compete for resources. These significant biological obstacles can potentially cause complete yield loss if inappropriately managed. In addition, future climate change can cause rice weeds to become more competitive against cultivated rice plants by providing new favourable conditions for the unwanted species to expand aggressively. As the effect of climate change on rice weeds has been studied, the abiotic parameters, including carbon dioxide concentration, atmospheric temperature, drought, and soil salinity, can be used to construct predictive modelling to forecast rice weed infestation. Suppose the weed invasion in rice fields can be predicted accurately based on the weather information. In that case, the farmers can prepare the countermeasure early to avoid high yield loss. However, some challenges must be faced by the researchers as the weed invasion depends not only on the climate alone. This review summarises the effect of climatic variation on weed infestation in rice fields. It also discusses how predictive modelling had been developed based on the information on the environmental conditions.