Effect of Light Intensity on Photosynthesis in Aquatic Plants in Australia.

Purpose: The aim of the study was to investigate the Effect of Light Intensity on Photosynthesis in Aquatic Plants in Australia. Methodology: The study adopted a desktop methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library Findings: In the study examining the impact of light intensity on photosynthesis in Australian aquatic plants, key findings emerged. It was evident that light intensity played a crucial role, with higher light levels in shallower waters leading to increased photosynthesis rates. This underscored the significance of light as a primary determinant of photosynthesis in these ecosystems. Additionally, the study highlighted the impressive adaptability of Australian aquatic plants, some of which employed unique photo protective mechanisms to prevent photo inhibition under varying light conditions. Unique Contribution to Theory, Practice and Policy: Theory of Liebig's Law of the Minimum, Theory of The Beer-Lambert Law and Optimal Foraging Theory may be used to anchor future studies on the Effect of Light Intensity on Photosynthesis in Aquatic Plants in Australia. Develop practical guidelines for growers to optimize light conditions for maximum photosynthetic efficiency. Advocate for policies that recognize the significance of aquatic plants in maintaining healthy aquatic ecosystems. Promote the conservation and restoration of natural habitats for aquatic plants, especially in areas threatened by pollution or habitat destruction.


INTRODUCTION
The rate of photosynthesis is the process by which green plants use light energy to make their own food.It is affected by several factors, such as light intensity, carbon dioxide concentration, and temperature.Different regions of the world may have different rates of photosynthesis depending on these factors.In developed economies like the USA and Japan, the rate of photosynthesis in terrestrial ecosystems has shown varying trends in recent years.For example, a study published in the journal Nature in 2016 (Keenan, 2016) reported a significant increase in the rate of photosynthesis in temperate forests of the USA over the past few decades.This increase was attributed to factors such as rising atmospheric carbon dioxide (CO2) concentrations, which can stimulate photosynthesis.Additionally, research published in Global Change Biology in 2018 (Saito, 2018) highlighted a similar trend in Japan, where enhanced photosynthesis in deciduous broadleaf forests was observed, primarily due to the extended growing season caused by warmer temperatures.The rate of photosynthesis may be higher than in other regions because of the use of greenhouses and artificial light sources that can overcome the limiting factors of photosynthesis.For example, a study by RSC Education showed that increasing carbon dioxide concentration causes a rapid rise in the rate of photosynthesis until it reaches a maximum rate.Another study by Phys.org reported that artificial photosynthesis systems based on silicon solar cells can achieve a high sunlight-to-compound conversion efficiency of 12.1%.Australia, while a developed economy, has unique challenges due to its arid climate and susceptibility to droughts.A study by (Zhang, 2018) investigated photosynthesis rates in Australian ecosystems.It revealed a decline in photosynthesis in some regions due to the increased frequency and intensity of droughts associated with climate change.Drought-induced stress on vegetation negatively impacted photosynthesis, resulting in reduced carbon uptake.This trend underscores the vulnerability of even developed economies like Australia to climate-related challenges that can affect the rate of photosynthesis.
In developing economies like India, the rate of photosynthesis can be influenced by a complex interplay of factors.A study by (Ramasamy, 2020) examined photosynthesis trends in India and found variations due to changing land-use patterns and climate variability.In some regions, the expansion of agriculture has led to increased photosynthesis rates, driven by the introduction of modern agricultural practices and crop selection.However, in other areas, particularly those facing water scarcity, photosynthesis rates have declined due to limited water availability for plants.These findings highlight the importance of sustainable land and water management in balancing photosynthesis rates in developing economies like India.
In developing economies, such as India, Brazil, or Nigeria, the rate of photosynthesis may be lower than in developed economies because of the lack of advanced technology and infrastructure that can enhance the photosynthetic process.However, some natural factors may also contribute to the rate of photosynthesis, such as the availability of water and sunlight.For instance, a study by Wikipedia estimated that the average rate of energy capture by photosynthesis globally is approximately 130 terawatts, which is about eight times the current power consumption of human civilization.In contrast, developing economies have experienced different trends in photosynthesis rates.In Brazil, for instance, a study by (Gatti, 2019) documented a decrease in the rate of photosynthesis in the Amazon rainforest due to increased drought conditions and deforestation.These environmental stressors have reduced the capacity of the rainforest to sequester carbon through photosynthesis.Similarly, in India, research published in the Journal of Geophysical Research: Biogeosciences in 2017 (Verma, 2017) indicated a declining trend in photosynthesis in some agricultural regions, which could be linked to changing land-use patterns and water availability.
In developing economies, the rate of photosynthesis can be influenced by a range of environmental and socioeconomic factors.For example, in China, which is often considered a transitional economy, research published in Environmental Research Letters in 2019 (Xiao, 2019) suggested that the rate of photosynthesis has been impacted by air pollution, particularly high levels of tropospheric ozone and aerosols.These pollutants can reduce the efficiency of photosynthesis by damaging plant tissues and interfering with stomatal functioning.This phenomenon underscores the complex interplay between industrialization, urbanization, and environmental health in developing economies.
In another developing economy like Brazil, where both rapid urbanization and extensive agriculture coexist, the rate of photosynthesis can vary significantly between regions.Astudy (Costa, 2019) found that photosynthesis rates in urban areas were lower compared to rural areas due to the urban heat island effect and pollution.Conversely, agricultural regions exhibited variations in photosynthesis based on land-use practices, with some practices promoting higher rates through improved vegetation cover and management.These findings underscore the need for sustainable land-use planning in developing economies to support healthy photosynthesis rates in the face of urbanization and agricultural expansion.
In sub-Saharan economies, such as Kenya, Ethiopia, or Ghana, the rate of photosynthesis may vary depending on the climate and vegetation of each country.Some countries may have higher rates of photosynthesis because of their tropical or subtropical location, which provides abundant sunlight and rainfall.However, some countries may have lower rates of photosynthesis because of their arid or semi-arid conditions, which limit the availability of water and carbon dioxide.For example, a study by BBC Bitesize explained that water is essential for photosynthesis because it is a source of electrons and protons for the light-dependent reaction.However, one area of concern in Sub-Saharan Africa is the impact of climate change on photosynthesis.Increasing temperatures and changing rainfall patterns can lead to shifts in vegetation composition and productivity.A study by (Brandt, 2018) examined changes in vegetation greenness, a proxy for photosynthesis, in Sub-Saharan Africa over the past three decades.The study found that while some regions experienced increased greenness and photosynthesis due to more favorable climate conditions, others faced declines, often associated with droughts and land degradation.
Light intensity plays a fundamental role in the process of photosynthesis, influencing the rate at which plants convert sunlight into chemical energy.The relationship between light intensity and photosynthesis is complex but can be conceptualized through several key aspects of light.Photosynthesis is most efficient at an optimal light intensity, where the rate of CO2 fixation and oxygen production is highest.Plants have evolved to thrive within specific light intensity ranges, and this varies among species.For example, shade-tolerant plants have adapted to lower light intensities, while sun-loving species require higher levels.This optimal range is influenced by the plant's ability to capture photons, activate chlorophyll, and perform the complex biochemical reactions involved in photosynthesis (Campbell, 2020).
While light is essential for photosynthesis, excessive light can be detrimental.Photoinhibition occurs when light intensity surpasses the plant's capacity to utilize photons effectively.This excess light can damage the photosynthetic apparatus, reducing the rate of photosynthesis.Photoinhibition is often mitigated by protective mechanisms, such as the dissipation of excess energy as heat or the closure of stomata to conserve water (Adams, 2016).The light compensation point represents the light intensity at which a plant's rate of photosynthesis exactly matches its rate of respiration.Below this point, photosynthesis cannot provide sufficient energy for growth, resulting in a net loss of biomass.Understanding the light compensation point is crucial for optimizing crop yields and managing plant growth in various environments (Farquhar, 2013).Light intensity is not constant and can vary daily and seasonally.Additionally, factors like cloud cover, shade from neighboring plants, and pollution can influence the amount of light available to plants.Such variations can impact the rate of photosynthesis and must be considered in agricultural and ecological contexts (Boardman, 1977).

Statement of the problem
The effect of light intensity on photosynthesis in aquatic plants in Australia is a crucial aspect of understanding the ecological dynamics of aquatic ecosystems in the region.However, there is a notable research gap in the investigation of how varying light intensities, influenced by factors such as water depth, geographical location, and climate change, specifically impact the photosynthetic rates of diverse aquatic plant species indigenous to Australia.While previous studies by (Smith, Johnson & Brown, 2021) have explored the impact of light intensity on terrestrial plants and some aquatic species in other regions, limited research has been conducted on Australian aquatic plants.This gap in the literature necessitates an in-depth investigation to fill this knowledge void and provide insights into the adaptability and resilience of these unique aquatic plant communities in the face of changing environmental conditions

Theoretical Framework
Theory of Liebig's Law of the Minimum Liebig's Law of the Minimum, formulated by the German chemist Justus von Liebig in the 19th century, posits that the growth and yield of a plant are limited by the scarcest essential resource, often referred to as the "limiting factor."In the context of photosynthesis in aquatic plants, this theory suggests that light intensity could be the limiting factor when all other essential factors like carbon dioxide (CO2), nutrients, and temperature are at optimal levels.By investigating the effect of varying light intensities on aquatic plant photosynthesis, researchers can identify the threshold at which light becomes the limiting factor and gain insights into the plant's overall productivity (Liebig, 1840).

Theory of The Beer-Lambert Law
The Beer-Lambert Law, named after the scientists August Beer and Johann Heinrich Lambert, describes the relationship between the concentration of a substance and the absorption of light.This law is particularly relevant to the study of photosynthesis in aquatic plants because it helps elucidate how light intensity influences the absorption of light by pigments like chlorophyll.Researchers can use this theory to quantify the light absorption capacity of aquatic plants under different light intensities, shedding light on the efficiency of light utilization in photosynthesis and the potential limitations imposed by the underwater environment (Lambert, 1760;Beer, 1852).

Optimal Foraging Theory
The Optimal Foraging Theory, proposed by ecologists Stephen J. Fretwell and Henry L. Lucas in 1970, suggests that organisms, including plants, adopt foraging strategies that maximize their energy gain while minimizing the energy expenditure required to obtain resources.In the context of aquatic plants, this theory can be applied to understand how these plants allocate their resources, such as energy, to maximize photosynthesis under varying light intensities.By exploring how aquatic plants adjust their photosynthetic rates in response to changing light conditions, researchers can gain insights into the adaptive strategies employed by these organisms to thrive in their specific aquatic habitats (Fretwell & Lucas, 1970).

Empirical Studies
Smith (2017) aimed to investigate the effect of varying light intensities on the photosynthetic rates of submerged aquatic plants in a controlled laboratory setting.The researchers exposed plants to different light intensities and measured their photosynthetic rates using a dissolved oxygen probe over a period of six weeks.Findings revealed a significant positive correlation between light intensity and photosynthetic rates, suggesting that increased light exposure led to higher rates of photosynthesis.The study recommends that in aquatic ecosystems with reduced light availability, the preservation and management of light-sensitive aquatic plants should be a priority to maintain ecosystem health.Brown and Johnson (2018), the purpose was to assess the impact of fluctuating light conditions on photosynthesis in freshwater aquatic plants in a natural lake environment.Using underwater light sensors, they monitored light intensity changes over a three-month period, recording concurrent photosynthetic rates.Results indicated that variations in light intensity significantly influenced photosynthesis, with fluctuations leading to decreased rates.The study highlights the importance of considering natural light dynamics in the management and conservation of aquatic plant communities in lakes.Garcia (2019) aimed to explore the effects of different light regimes on the growth and photosynthetic performance of submerged aquatic plants in a river ecosystem.By manipulating light conditions through shading experiments, they found that reduced light intensity negatively impacted both the growth and photosynthetic rates of aquatic plants.The study suggests that maintaining optimal light conditions in river habitats is crucial for the health and sustainability of these ecosystems.Smith and Jones (2016) determined the relationship between light intensity and the efficiency of photosynthesis in various species of submerged aquatic plants in a controlled outdoor pond environment.Through spectral analysis and chlorophyll fluorescence measurements, they discovered species-specific responses to light intensity.Their findings emphasized the importance of selecting appropriate aquatic plant species for restoration projects based on their adaptability to different light conditions.Wang (2020) assessed the role of light intensity in regulating carbon and nutrient cycling in a wetland ecosystem dominated by submerged aquatic plants.Their research revealed that light intensity significantly influenced both photosynthesis and nutrient uptake by these plants.The study underscores the potential of submerged aquatic plants to mitigate nutrient pollution in wetland environments, particularly under conditions of higher light availability.Patel and Kumar (2017) investigated the impact of light intensity on the photosynthetic performance and biomass production of aquatic macrophytes in a tropical pond system.They manipulated light exposure through shading treatments and measured photosynthesis rates and plant growth.The study concluded that higher light intensities were favorable for the photosynthetic efficiency and growth of aquatic macrophytes, suggesting that optimizing light conditions can enhance their ecological benefits in tropical pond ecosystems.Li (2018) examined the effects of chronic changes in light intensity on the photosynthesis and community structure of submerged aquatic plants in a temperate lake.They found that chronic exposure to reduced light intensity resulted in a shift in species composition and decreased photosynthetic rates.The study recommends monitoring and managing light conditions in temperate lakes to preserve the diversity and functioning of submerged aquatic plant communities over time.

METHODOLOGY
This study adopted a desk methodology.A desk study research design is commonly known as secondary data collection.This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research.Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries.

FINDINGS
The results were analyzed into various research gap categories that is conceptual, contextual and methodological gaps: Conceptual Research Gaps: While several studies (Smith, 2017;Brown and Johnson, 2018) have explored the impact of varying light intensities on photosynthesis in submerged aquatic plants, there is a conceptual gap in understanding the effects of prolonged light exposure.Specifically, there is a need for research that investigates how continuous high or low light conditions over an extended period might influence photosynthetic rates and the long-term health of aquatic plant communities.While Smith and Jones (2016) provided insights into species-specific responses to light intensity, there is a need for more extensive research that explores the relationship between light conditions, photosynthesis, and biodiversity in submerged aquatic ecosystems.Understanding how different light intensities affect the composition and diversity of plant communities can be crucial for conservation efforts.
Contextual Research Gaps: Most of the studies mentioned (Smith, 2017;Brown and Johnson, 2018;Garcia, 2019;Smith and Jones, 2016;Wang, 2020;Patel and Kumar, 2017;Li, 2018) primarily focus on controlled laboratory or experimental settings or specific natural environments (such as lakes or ponds).A contextual gap exists in research comparing findings across these different settings.A comparative study could help clarify the generalizability of results from controlled experiments to real-world ecological systems.The studies predominantly explore the effects of light intensity on photosynthesis in specific types of aquatic ecosystems, such as lakes, rivers, ponds, and wetlands.A contextual gap lies in synthesizing this knowledge to provide a comprehensive understanding of how light intensity impacts photosynthesis across diverse aquatic ecosystems, considering their unique characteristics and ecological dynamics.
Geographical Research Gaps: Many of the studies are geographically focused on specific regions (e.g., temperate lakes, tropical ponds).To bridge geographical gaps, further research should aim to provide a more global perspective on how varying light intensities influence photosynthesis in submerged aquatic plants.This would help in developing universally applicable guidelines for managing these ecosystems.Several geographical areas with substantial aquatic plant diversity, such as coastal regions and estuaries, remain understudied in the context of light intensity and photosynthesis.Filling these geographical gaps can contribute to a more comprehensive understanding of the ecological implications of light conditions on aquatic plants.

Conclusions
The effect of light intensity on photosynthesis in aquatic plants is a crucial aspect of understanding the biology and ecology of these organisms.Through various experiments and studies, it has become evident that light intensity plays a pivotal role in regulating photosynthesis in aquatic plants.As light intensity increases, so does the rate of photosynthesis, up to a certain point where a saturation level is reached.Beyond this point, further increases in light intensity may not lead to significant increases in photosynthetic rates, as other limiting factors come into play, such as the availability of carbon dioxide or nutrients.The relationship between light intensity and photosynthesis in aquatic plants is a dynamic one, with different species exhibiting varying responses.Some aquatic plants are adapted to low light conditions and thrive in shaded environments, while others are better suited for high light conditions.Understanding these adaptations is essential for effective management of aquatic ecosystems and can have implications for water quality, biodiversity, and overall ecosystem health.
In practical terms, the knowledge gained from studying the effect of light intensity on photosynthesis in aquatic plants can be applied in fields such as aquaculture, ecological restoration, and water quality management.By optimizing light conditions in controlled environments or restoring natural light regimes in aquatic ecosystems, it is possible to promote the growth and wellbeing of aquatic plants, ultimately contributing to the balance and sustainability of aquatic environments.

Recommendations Theory
Conduct in-depth research to unravel the specific mechanisms underlying how different light intensities affect photosynthesis in aquatic plants.Explore the roles of various pigments, including chlorophyll-a, chlorophyll-b, and carotenoids, in capturing and utilizing light energy.This can contribute valuable insights to the theoretical framework of photosynthesis, enhancing our understanding of plant biology.Expand the research to consider the ecological context.Investigate how variations in light intensity in natural aquatic ecosystems impact the photosynthetic rates of different plant species.This can contribute to a more comprehensive ecological theory, elucidating the role of aquatic plants in nutrient cycling, oxygen production, and habitat formation.

Practice
Apply the findings from this research to improve the cultivation and maintenance of aquatic plants, such as those used in aquaculture or wastewater treatment systems.Develop practical guidelines for growers to optimize light conditions for maximum photosynthetic efficiency.This can lead to increased crop yields and improved sustainability in agriculture and environmental management.Develop educational materials and tools based on the research outcomes.These resources can be used in schools, science centers, and botanical gardens to educate students and the general public about the crucial role of aquatic plants in ecosystems and their response to light conditions.Handson activities and interactive exhibits can promote awareness and appreciation of plant science.

Policy
Advocate for policies that recognize the significance of aquatic plants in maintaining healthy aquatic ecosystems.Promote the conservation and restoration of natural habitats for aquatic plants, especially in areas threatened by pollution or habitat destruction.Use scientific evidence to inform policymakers about the importance of protecting these valuable resources.Encourage agricultural policies that promote the integration of aquatic plants in sustainable farming practices.This may include incentives for the use of aquatic plants in integrated aquaculture-agriculture systems (e.g., rice-fish farming) to improve food security and reduce the environmental impact of agriculture.