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Cover page of High Priority Invasive Species in Los Angeles County

High Priority Invasive Species in Los Angeles County

(2021)

Human activities have interfered with the distribution ranges and dispersal barriers of many species for hundreds of years. Common methods of accidental dispersal include the use of contaminated equipment and the release of exotic pets (Hardion et al., 2014). The introduction of a species may also be deliberate, such as the relocation of species into a novel area for gardening, construction, erosion control, or food production (Hardion et al., 2014). Anthropogenically introduced species may threaten local ecosystem biodiversity by outcompeting native species for resources (Hardion et al., 2014). Therefore, the introduction of non-native species, which are key drivers of human-induced environmental change globally (Vitousek et al., 1997), alter the evolutionary trajectory of native species. This is accomplished by means of competitive exclusion, niche displacement, hybridization, predation, and ultimately, extinction (Shea, 2002). Species categorized as either threatened or endangered are particularly vulnerable to extinction (Wilcove et al., 1998). The resulting loss of native species constitutes an irreversible removal of evolutionary potential (Mooney et al., 2001), as well as a critical cause of ecosystem degradation.

The negative impact of invasive species on ecosystem health extend to a multitude of ecosystem goods such as agricultural products and fisheries. They also hinder ecological services that are typically provided by native species, such as clean drinking water and climate stabilization. This poses a threat because ecosystem goods and services are fundamental to human well-being (Daily et al., 1997). Translating this impact into a monetary value is often challenging. The lack of a concrete and precise economic impact assessment allow the burdens imposed by invasive species to be overlooked. This results in an “invisible tax” on ecosystem services that is rarely considered during decision making (Pejchar and Mooney, 2009).

Furthermore, invasive species have a direct impact on human and animal health (e.g., via toxins, thorns, and allergenic pollen). For example, mosquitoes, which are common vectors for disease, are capable of altering the transmission cycle of pathogens (Juliano and Lunibos, 2005). The introduction of new species of mosquitoes into novel areas has been facilitated by worldwide ship transport (Lunibos, 2002).

Given the broad and substantial burden of invasive species, urgency is required to control and limit their harmful impacts. Such a feat would necessitate specific knowledge regarding their biology, ecology, and geographic origin (Hardion et al., 2014). In the following review, we conducted a thorough assessment of five key invasive species in the County of Los Angeles, providing information on their origins, current distribution, ecological and health impacts, economic costs, as well as ideal management guidelines founded in scientific research.

Cover page of A Geospatial Approach to Conservation Prioritization: Examining the Applications of GIS-based Vegetation Data in Los Angeles County

A Geospatial Approach to Conservation Prioritization: Examining the Applications of GIS-based Vegetation Data in Los Angeles County

(2021)

The California Floristic Province is one of the world’s biodiversity hotspots, one of 36 regions which contain over half of the world’s vegetation. With projected increases in anthropogenic land transformation and use, omnipresent impacts of global climate change, and threats of habitat fragmentation and loss, understanding the vegetation composition of Los Angeles County is integral to prioritizing conservation efforts. By creating one continuous dataset with regional dominant alliance type for the entirety of the county, rare vegetation types and their locations can be identified. The goal of this project is to create such data set and produce maps and associated analyses to create a comprehensive overview of the rare vegetation in Los Angeles County, highlight at-risk regions and any current gaps in protection, providing information and framework for structuring future management and conservation projects.

Cover page of 2019 Sustainable LA Grand Challenge Environmental Report Card for Los Angeles County Water

2019 Sustainable LA Grand Challenge Environmental Report Card for Los Angeles County Water

(2019)

The Sustainable LA Grand Challenge (SLA GC) Environmental Report Card (ERC) for Los Angeles County (L.A. County) is the only comprehensive environmental report card for a megacity in the world. This 2019 ERC on Water provides an in-depth look at the region's efforts in moving toward a more resilient local water supply, which requires maximizing high-quality local water supplies, improving water conveyance and treatment infrastructure, reducing water consumption, and implementing innovative technology and policy solutions. Twenty indicators were assessed across eight categories. Many of these indicators are new areas of assessment for the ERC and will provide a more comprehensive picture of current conditions compared to the 2015 ERC that last assessed L.A. County’s water. Grades were assigned in each category based on compliance with environmental laws or numeric standards where applicable, on our best professional judgment, and on historical improvements and context. This year’s grades range from D/ Incomplete to B+, and although there has been great progress in some areas, others still require significant improvement to raise the county’s C+ average.

Cover page of LA Sustainable Water Project: Los Angeles City-Wide Overview

LA Sustainable Water Project: Los Angeles City-Wide Overview

(2018)

This report assesses the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local water supplies for the City of Los Angeles (the City).  This final report summarizes the current practices and future opportunities at the City-owned Water Reclamation Plants and underlying groundwater basins and highlights the importance of considering all aspects of integrated water management even when dealing with water quality or supply-focused projects.  

Implementing watershed-scale best management practice programs to meet stormwater permit requirements will significantly improve water quality in all watersheds.  However, additional mechanisms such as increasing Low Impact Development implementation and comprehensive source tracking and source control mechanisms will be required to potentially eliminate water quality exceedances.  There are multiple efforts occurring in the City and the region to increase the recharge of recycled water into the ground and the volumes of remediated groundwater extracted. 

This research further assessed the impacts of potential water supply portfolios, with greater volumes of locally-supplied water, on GHG emissions and energy needs of supplying LA’s water.  Conservation will be another powerful tool to decrease our dependence on imported water.  This research demonstrates the complex interrelationships between all aspects of urban water management, including, for example, stormwater management and local water supply.

Cover page of LA Sustainable Water Project: Los Angeles River Watershed

LA Sustainable Water Project: Los Angeles River Watershed

(2017)

The LA Sustainable Water Project: Los Angeles River Watershed report explores the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local water supplies for the City of Los Angeles (the City) in the highly urbanized Los Angeles River (LAR) watershed.To assess the integrated water landscape in this watershed, the report also looks at current practices and future opportunities at the Donald C Tillman, LA Glendale, and Burbank Water Reclamation Plants (WRPs) and in the underlying Upper LA River Area (ULARA) adjudicated groundwater basins. Implementing watershed-scale best management practice programs to meet stormwater permit requirements will significantly improve water quality. However, additional mechanisms such as increasing Low Impact Development implementation and comprehensive source tracking and source control mechanisms will be required to potentially eliminate water quality exceedances. The 3 WRPs in the watershed currently discharge more than 30 million gallons per day of treated wastewater into the River; an increased focus on increasing local water supply could lead to a reduction in these discharges.

The combination of increased stormwater capture and increased use of recycled water in the LAR watershed could lead to lower flows in the LAR and impact habitat and recreational uses; further study is needed to characterize potential impacts and identify optimal flows for the future of the LAR. The City is leading efforts in ULARA to increase the recharge of recycled water into theground by 30,000 acre feet per year and increase the volumes of remediated groundwater extracted by around 120,000 acre feet per year. This research demonstrates the complex interrelationships between all aspects of urban water management, including stormwater management and local water supply.

Cover page of LA Sustainable Water Project: Dominguez Channel & Machado Lake Watersheds

LA Sustainable Water Project: Dominguez Channel & Machado Lake Watersheds

(2017)

This report explores the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local-water supplies for the City of Los Angeles (the City) in the highly urbanized Dominguez Channel (DC) and Machado Lake (ML) watersheds.  To assess the integrated water landscape in this watershed, the report also looks at current practices and future opportunities at the Terminal Island Water Reclamation Plant (TIWRP) and in the underlying adjudicated groundwater basins: West Coast Basin and Central Basin.  

Implementing watershed-scale best management practice programs to meet stormwater permit requirements will significantly improve water quality in these watersheds. However, additional mechanisms such as implementing the City’s Low Impact Development ordinance and comprehensive source tracking and source control mechanisms will be required to potentially eliminate water quality exceedances.   

TIWRP currently treats nearly 15 million gallons per day (MGD) of wastewater with advanced-water treatment for reuse; however, sufficient demand exists locally to utilize approximately 25 MGD.  West Coast and Central Basins provide multiple opportunities to increase our local water supply through increasing recharge and extraction in these basins, including 450,000 acre feet of available dewatered space in the basins.  This research demonstrates the complex interrelationships between all aspects of urban water management, including, for example, stormwater management and local water supply.

Cover page of Enhanced PM2.5 pollution in China due to aerosol-cloud interactions

Enhanced PM2.5 pollution in China due to aerosol-cloud interactions

(2017)

Aerosol-cloud interactions (aerosol indirect effects) play an important role in regional meteorological variations, which could further induce feedback on regional air quality. While the impact of aerosol-cloud interactions on meteorology and climate has been extensively studied, their feedback on air quality remains unclear. Using a fully coupled meteorology-chemistry model, we find that increased aerosol loading due to anthropogenic activities in China substantially increases column cloud droplet number concentration and liquid water path (LWP), which further leads to a reduction in the downward shortwave radiation at surface, surface air temperature and planetary boundary layer (PBL) height. The shallower PBL and accelerated cloud chemistry due to larger LWP in turn enhance the concentrations of particulate matter with diameter less than 2.5 μm (PM2.5) by up to 33.2 μg m−3 (25.1%) and 11.0 μg m−3 (12.5%) in January and July, respectively. Such a positive feedback amplifies the changes in PM2.5 concentrations, indicating an additional air quality benefit under effective pollution control policies but a penalty for a region with a deterioration in PM2.5 pollution. Additionally, we show that the cloud processing of aerosols, including wet scavenging and cloud chemistry, could also have substantial effects on PM2.5 concentrations.

Cover page of 2017 Sustainable LA Grand Challenge Research Symposium Program

2017 Sustainable LA Grand Challenge Research Symposium Program

(2017)

On May 17, 2017, Sustainable LA Grand Challenge (SLA GC) hosted their first symposium showcasing cutting-edge research toward the goal of 100% renewable energy, 100% locally sourced water, and enhanced ecosystem and human health in Los Angeles County by 2050.

Cover page of Artes: An Integrated Model of Water Supply in L.A. County

Artes: An Integrated Model of Water Supply in L.A. County

(2017)

Artes is a model of water management in metropolitan Los Angeles. It was developed to investigate the potential for maximizing local water supplies and reducing imports across Los Angeles and its hundreds of water agencies. Model results have helped assess the implications of local water supply on urban water systems reliability, stormwater capture and water reuse, groundwater management, environmental flows, economics, and urban landscapes (trees and plants). The model is a product of the California Center for Sustainable Communities at UCLA and was developed through a collaborative research network spanning UCLA, the University of Utah, and Colorado School of Mines. The project was funded through the National Science Foundation's Water, Sustainability, and Climate program. 

Cover page of 2017 Sustainable LA Grand Challenge Environmental Report Card for Los Angeles County Energy and Air Quality

2017 Sustainable LA Grand Challenge Environmental Report Card for Los Angeles County Energy and Air Quality

(2017)

The 2017 Sustainable LA Grand Challenge Environmental Report Card (ERC) for Los Angeles County (LA County) on Energy and Air Quality offers an in-depth look at the region’s sustainability efforts focusing on the energy we use, greenhouse gas emissions, and the air we breathe. The LA County Environmental Report Card is the only comprehensive environmental report card for a megacity in the world. This ERC assesses 21 indicators that fall into five categories: Stationary Energy Use; Transportation; Renewable Energy Resources; Greenhouse Gas Emissions; and Air Quality and Human Health Impacts. A majority of these indicators are entirely new areas of inquiry for the ERC, and together will provide a broader picture of current conditions compared to the 2015 ERC. Grades were assigned in each category based on compliance with environmental laws or numeric standards where applicable, on our best professional judgment, and on historical improvements and context. This year’s grades range from C-/ Incomplete to B, and although there is progress towards meeting local and state goals, and a number of new standards and regulations that will undoubtedly have a positive impact in years to come.