Why are alpine lakes particularly sensitive to acid deposition?

Alpine lakes are particularly sensitive to acid deposition due to their low buffering capacity and slow recovery rates.

Alpine lakes, often found in high mountainous regions, are typically characterised by their low alkalinity. Alkalinity, in this context, refers to the capacity of water to neutralise acids, also known as its buffering capacity. The lower the alkalinity, the less capable the water is of neutralising incoming acids. This makes alpine lakes particularly vulnerable to acid deposition, as they lack the necessary buffering capacity to neutralise the acids, leading to a decrease in pH levels and an increase in acidity.

The geology of the regions where alpine lakes are found often consists of hard, crystalline bedrock. This type of rock is poor in carbonate minerals, which are crucial for neutralising acids. Therefore, the surrounding geology does not provide sufficient buffering substances to the lake, exacerbating their sensitivity to acid deposition.

Furthermore, alpine lakes are often isolated and have slow recovery rates. They are typically located in remote, high-altitude areas with harsh climatic conditions, which limit biological activity and slow down the process of recovery from acidification. The cold temperatures slow down chemical reactions, including those that could help neutralise the acid. Additionally, the isolation of these lakes means they are less likely to receive fresh inputs of less acidic water from other sources, which could help dilute the acid.

Lastly, the ecosystems of alpine lakes are adapted to very specific, stable conditions. Changes in pH can have significant impacts on the aquatic life, including fish and microorganisms, which may not be able to tolerate the increased acidity. This can lead to a loss of biodiversity and disrupt the ecological balance of the lake.

In conclusion, the sensitivity of alpine lakes to acid deposition is due to a combination of their low buffering capacity, the geology of their surroundings, their isolation and slow recovery rates, and the specific adaptations of their ecosystems.