The unbridled growth in pollution on the planet has had adverse effects on many processes in nature. One of those essential processes that transfer energy among organisms in an ecosystem is primary productivity.
It is the production of new organisms or organic matter by plants and autotrophs. The rise of pollution and its potential effects on primary productivity are the emphases of this literature.
Gross Primary Production
Gross primary production or the conversion of carbon dioxide into sugar is one of the foundational processes for every ecosystem. Photosynthetic energy fixation by green plants (or ‘primary production’) is the most basic ecological process of the biosphere.
Gross primary production also refers to the number of carbon compounds produced by plants during photosynthesis in a given ecosystem and timeframe.
To put it in even simpler words, it is the energy absorbed by a plant to convert into chemical energy during the process of photosynthesis.
Some of this energy is used by the autotroph itself for its metabolism or respiration. Net primary production is the gross primary production minus aerobic respiration.
Gross Primary Productivity
Gross primary productivity is the rate of production of carbon compounds by plants or autotrophs during photosynthesis in a given ecosystem within a given timeframe or per unit area per unit of time.
Net primary productivity is gross primary productivity excluding the energy captured for metabolic processes. Therefore, gross primary productivity will always be more than net primary productivity.
It is understood that climate change causes significant shifts in GPP from a local to a global scale. Pollution is a crisis that is responsible for great damage to the earth in terms of human life and capital.
Several pollutants are potent to cause detrimental effects over primary production. These pollutants can depress and stimulate primary production.
Eutrophication, acidification, and direct toxicity are the primary mechanisms of impact of pollutants that affect large ecosystem processes.
One such example is acid rain. Acid rain is known for having a negative impact on forests. Others are sulfur oxide, nitrogen oxide, ozone, and volatile organic compounds.
The effect of such pollution on terrestrial and marine ecosystems will be further studied and reviewed to understand how gross primary productivity has been affected by pollution.
What Are The Factors That Directly Affect Gross Primary Productivity
Several factors affect autotrophs on land and water, i.e. plants and phytoplanktons, and they are listed below:
- Availability of Light
- Availability of Nutrients
- Compensation Depth
- Photosynthetic Capacity
- Species Composition
- Species Succession
As pollution lingers in the same environment as autotrophs, it gradually begins to have adverse effects on either of these factors that cascade to gross primary productivity.
What Are The Pollutants That Affect Gross Primary Productivity?
Microplastics have a detrimental impact on zooplankton organisms wherein primary productivity is affected. As global plastic production increases year after year, most of the plastic waste makes its way into the marine environment due to an improper waste management system.
Slowly but steadily, plastic debris contaminates the marine environment by reaching microscopic scales and reducing growth reduction.
A study in 2016 concluded that algal growth was reduced by 45% due to the high concentration of plastic particles in their environment.
Individual algae have also shown negative effects on primary productivity due to the contamination of microplastics in their environment.
Ozone and haze pollution
Surface ozone or tropospheric ozone is a pollutant known to have a drastic impact on plant productivity. Industrial and rural regions alike have been subject to tropospheric ozone with impacts on agriculture and climate change.
Plant productivity is reduced by the entry of tropospheric ozone into the leaves by the way of stomata. After its entry, its effects are seen in the reduction of photosynthesis, accumulation of biomass, and resultant oxidative stress.
Chlorinated hydrocarbons are one of the most prevalent chemicals in use in modern society. It is present in pesticides and insecticides that gradually accumulate in the ocean and linger in the environment.
In 1968, it was Wurster who first raised an alarm regarding the negative impact of chlorinated hydrocarbons on primary production in the oceans.
Primary production in marine Algae decreased by 50-80 percent and these findings were confirmed over the years with subsequent years.
Although this reduction varied among certain types of Algae and phytoplankton, they all displayed apparent effects.
Methyl-mercury, a result of the methylation of mercury, has utility as a fungicide, and disinfectant apart from its use in batteries and fluorescent bulbs.
It also contaminates freshwater in the form of mercury through soil runoffs and effluents from the industry.
Due to its high rate of toxicity and biomagnification, methylmercury has hazardous effects on aquatic primary productivity.
There has been an evident impact on photosynthesis, including oxidative stress in producers, hormone metabolism, nutrient metabolism, and cell growth.
Soil pollution has become rather common due to anthropogenic activities that raise the concentration of metals in the soil. One such metal is copper.
A higher concentration of copper in the soil makes it a toxicant to plants, according to a study done in 2007.
This is due to its inhibitory effects on the biochemical, proteomic, and physiological levels of plant cells. Studies have shown a reduction in the germination rate as well as plant biomass.
Hence, there is a strong correlation between plants in copper-contaminated soils and their biochemical changes.
Ciprofloxacin, a very commonly used fluoroquinolone has been found to inhibit the photosynthesis of organisms. Ciprofloxacin gets in the way of the transfer of energy and catalytic activity of reaction center II (RC-II).
The interference causes a delay in the kinetics of photoreduction. Other plants impacted by Ciprofloxacin displayed a reduction in the synthesis of leaves.
Therefore, Ciprofloxacin affects gross primary productivity by causing morphological deformities and influencing photosynthesis.
This literature concluded that there is a direct relationship between increasing pollution and decreasing gross primary productivity.
Gross primary productivity, the subject of pollution, various factors affecting primary productivity, and the pollutants affecting gross primary productivity have been discussed in detail.
Data regarding the pollutants that have affected gross primary productivity are well-established and adequately reviewed.
Further studies have widely suggested that pollution and climate change will continue to increase due to and despite the inadequate measures currently in place.
Such an increase will aggravate the damage to gross primary productivity beyond its current thresholds.
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