To determine the most likely long-term effect of increased salinity on the vegetation types listed, let's examine the given salinity data and compare the maximum salinity measured for each vegetation type against their typical salinity range.
1. Swamp:
- Typical Salinity Range: 0-0.5
- Maximum Salinity Measured: 8
- The maximum salinity measured (8) is much higher than the typical range (0-0.5), indicating that the salinity levels have significantly surpassed what swamps can typically tolerate.
2. Fresh Marsh:
- Typical Salinity Range: 0-3
- Maximum Salinity Measured: 26
- The maximum salinity measured (26) far exceeds the typical range (0-3), suggesting that the salinity levels are well above the tolerance limit for fresh marshes.
3. Intermediate Marsh:
- Typical Salinity Range: 2-8
- Maximum Salinity Measured: 26
- The maximum salinity measured (26) is significantly above the typical range (2-8), showing that intermediate marshes are also experiencing salinity levels beyond their normal tolerance.
4. Brackish Marsh:
- Typical Salinity Range: 4-10
- Maximum Salinity Measured: 34
- The maximum salinity measured (34) is much higher than the typical range (4-10), suggesting that brackish marshes are encountering salinity levels that are too high for their regular environment.
5. Saline Marsh:
- Typical Salinity Range: 8-29
- Maximum Salinity Measured: 30
- The maximum salinity measured (30) is slightly higher than the typical range (8-29), indicating that even saline marshes are experiencing salinity levels just above their usual tolerance.
Since the salinity levels in each type of vegetation area are exceeding their typical salinity ranges, especially by large margins in many cases, the plants that are currently found in these areas will struggle to survive. Over time, the areas would most likely undergo a shift in species composition.
Given that the salinity has increased substantially, the most likely long-term effect would be:
A shift in species composition to more salt-tolerant plants.
Increased salinity excludes salt-intolerant plants, and naturally, the environment will favor the growth and establishment of species that can withstand higher salinity levels. Thus, more salt-tolerant species will become more prevalent in these areas.
