Non-Forested Wetlands
Extremely heavy rainfall has become more common in Hawai'i, leading to increased runoff, erosion, and flooding. The number of consecutive wet days and dry days have been increasing in Hawai'i.
Increasing temperatures, an expanding human population, and increased cover of invasive shrubs and grasses, such as common gorse, fountain grass and guinea grass, all contribute to increased risk of wildfire in Hawai'i.
Warmer temperatures and decreased cloud cover in some areas are likely to result in greater evaporation rates, leading to reductions in water supply and increases in demand. Hawai'i has already experienced a trend toward increasing drought conditions during the winter rainy season. Decreased soil moisture increases plant stress, with impacts to agricultural and natural systems.
Warmer oceans are leading to increased coral bleaching and disease outbreaks and changing distribution of tuna fisheries. Freshwater supplies will become more limited on many islands. Coastal flooding and erosion will increase. Mounting threats to food and water security, infrastructure, health, and safety are expected to lead to increasing human migration.
Coastal wetlands will be impacted by sea level rise and changes in water chemistry. Those changes can alter wetland conditions and processes, including the types of habitat they provide, and their ability to manage water quality and flooding.
Changes in the timing of streamflow reduce water supplies for competing demands. Sea level rise, erosion, inundation, risks to infrastructure, and increasing ocean acidity pose major threats. Increasing wildfire, insect outbreaks, and tree diseases are causing widespread tree die-off.
Wet prairie is moderately vulnerable to climate change (when evaluated in low to high climate change emissions scenarios). Wet Prairies may be most vulnerable to changes in hydrology, increasing non-native invasive species, and invading brush. Changes to surface water hydrology are likely to occur with climate alterations to the hydrologic cycle. Thus leading to projected increases in droughts as well as the frequency and intensity of flood events.
Mesic Prairie is highly vulnerable to climate change (when evaluated in low to high climate change emissions scenarios). Mesic Prairie ecosystem occurs where soil depth and annual precipitation (and periodic fire) are primary drivers of prairie development and maintenance. Of all the prairie types, mesic prairie is considered to be the most vulnerable to climate change due to a combination of negative climate-related impacts and the small and isolated nature of remnants that confine and reduce opportunity to rearrange and migrate as a means to accommodate stressors.
Sand Prairie is moderately-low to moderately vulnerable to climate change (when evaluated in low to high climate change emissions scenarios). The Sand Prairie environment is intrinsically hot and arid, plants are adapted to growing on infertile soils and thus the species that grow in this natural community are able to resist potential climate change threats such as drought and extreme heat. It’s possible that the frequency, intensity and timing of precipitation along with increased dry periods between rains may affect groundwater infiltration and increase drought stress.
