Urban

Urban strategies and approaches.

Taxonomy Machine Name
niacs_strategy_urban
Taxonomy Alias
urban

Warming temperatures and changes in rainfall, now and into the future, are increasing the range of avian malaria to higher elevations, threatening numerous forest bird species.

Submitted by KGiesting on

Avian malaria is a primary factor in the decline of many Hawaiian forest birds, especially those of the family Fringillidae, such as the Hawaiian honeycreeper. Currently, high elevation forests are the only remaining refugia for some bird species, as avian malaria, and its associated vector, the southern house mosquito, is limited by temperature constraints.

Changes in mean annual rainfall (MAR) can lead to shifts in stream flow regimes in tropical watersheds, with impacts to aquatic organism habitat quality and downstream water supply.

Submitted by KGiesting on

Drier conditions with reduced groundwater recharge and stream discharge are expected in the future, as well as increased flow variability and instability. Projected declines in overall rainfall, increased magnitude of precipitation extremes (rainfall and drought), and increases in air and ocean temperatures are expected to contribute to changed stream flow regimes, including shifts in potential evapotranspiration, rates of infiltration, and onset and duration of surface runoff. Increased air temperatures and reductions in coastal precipitation have already reduced median base flow by 23%.

Future projections, through 2061, indicate a >30% decrease in carbon sequestration in terrestrial ecosystems.

Submitted by KGiesting on

Terrestrial ecosystems in Hawaii have a high carbon sequestration capacity due to the year-round warm, wet climate and highly fertile soils. However, decreases in carbon sequestration are predicted through 2061, due to decreases in net primary production (NPP), increased carbon losses from land-use change, and increased aquatic carbon-leaching losses to nearshore waters. Hawai'i island is projected to remain a net carbon sink through 2061, due to terrestrial carbon sequestration.

Two fungal pathogens, which cause the disease Rapid ‘Ōhi‘a Death (ROD), are leading to widespread loss of ‘ōhi‘a lehua, Hawai'i's most widespread native tree.

Submitted by KGiesting on

This fungal disease has the potential to alter the structure of ‘ōhi‘a dominated forests. Many native plants are likely vulnerable to ‘ōhi‘a mortality events. Protecting trees from damage by introduced feral ungulates can help reduce the prevalence of this fungal disease, as damage is often a precursor to infection.

Production potential for agroecosystems in the future, based on 3 different climate models, ranges from no change to decreases of up to 19% by end of century.

Submitted by KGiesting on

Indigenous agroecosystems can achieve the goals of conserving biodiversity while increasing food production. Species richness within agroecosystems is often comparable to adjacent forest reserves. Historic production from indigenous agriculture is estimated to have potentially yielded enough food to feed more than 1.2 million people each year.

Around 1990, the frequency of Trade Wind Inversions (TWI) increased dramatically. This has led to drier conditions in high elevation ecosystems.

Submitted by KGiesting on

The rainfall declines associated with increased frequency of TWI seem to be having ecological impacts, such as decreased rainfall in some areas. These changes impact native plants, such as the Haleakalā silversword, the populations of which have experienced a 60% decline since the early 1990s.

Hawaii is home to a wide variety of ecological habitats with more than 1000 native plant species; many are threatened or endangered.

Submitted by KGiesting on

90% of the terrestrial species are endemic (unique to the region), and many are threatened or endangered. Habitat loss and alteration, and the spread of invasive plants have all contribute to extinctions and ecosystem decline. Sea level rise is expected to severely impact low-lying areas, including coastal plants, nesting seabirds, seals, and turtles.

Sea surface temperatures and acidity are now the highest in recorded history. Coral bleaching is projected to occur annually by 2045.

Submitted by KGiesting on

Ocean acidification and coral bleaching will lead to loss of coastal habitats and negatively impact the productivity of fisheries. The productivity of ocean fisheries is anticipated to decline by up to 50% by late century. By late century, under a high emissions scenario, nearly all coral reefs are expected to be severely compromised by ocean acidification. Currently, coral reef cover is at 38%; by late century, the amount is projected to be less than 1%.