One Shared Region and Two Different Change Patterns: Land Use Change in the Binational Californian Mediterranean Region

Ricardo Eaton-Gonzalez,Eric Mellink

doi:10.3390/land4041138

Ricardo Eaton-Gonzalez, Eric Mellink

Open Access

https://doi.org/10.3390/land4041138

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Abstract

The Californian Floristic Province, ranging from Northern California, USA, to the northwestern portion of the state of Baja California, Mexico, is a region of great biological richness that has a high risk of loss of species due to the effect of human activities. The main stressor that threatens its biodiversity is the change in land use and vegetation cover, which severely impacts the environmental and socio-economic systems’ functioning, affecting the provision of environmental services including the maintenance of biodiversity. The Tijuana River Watershed (TRW) is located within this floristic province. It has experienced rapid population growth during the last 50 years, demanding development of infrastructure in areas where native vegetation existed. As a binational watershed, it is an ideal area to study the processes involved in fragmentation and connectivity of natural environments, since both countries, while sharing the same environment, contrast greatly in their economic and social systems, which impose different pressures to these shared natural resources. Our research addresses change in vegetation cover and land use in the TRW, analyzing the changes and differences between Mexico and the United States. This analysis will be a basis to propose future management strategies for the conservation of ecological processes and biodiversity, according to the policies and actions for land management and conservation in both countries.

Highlights

Conservation efforts have identified areas of greater biological richness and those that present high risk of loss of species due to human activities. These regions are known as hotspots [1] and of the 34 currently defined around the world, one is the Californian Floristic Province, which is shared between the northern portion of Baja California in Mexico and the states of California and Oregon in the United States (U.S.) (Figure 1)
Our research addresses the change in land use and vegetation cover in the Tijuana River Watershed (TRW) between 1990 and
The TRW is a 450,000 ha area shared between northwestern Baja California, Mexico and Southwestern California, U.S A little over 75% is located in Mexico [10,19,20,21] (Figure 1)

Summary

Introduction

Conservation efforts have identified areas of greater biological richness and those that present high risk of loss of species due to human activities These regions are known as hotspots [1] and of the 34 currently defined around the world, one is the Californian Floristic Province, which is shared between the northern portion of Baja California in Mexico and the states of California and Oregon in the United States (U.S.) (Figure 1). Between 1972 and 1994, the watershed lost 200 km of native vegetation from 85 patches in Mexico and 110 km from 87 patches in U.S [10] This process of change in land use from natural to urban occurs in three phases: pre-urban vegetation, construction phase, which exposes bare soil for one to three years, and mature phase with impervious surfaces and vegetation. Mexico and the U.S We propose that our analyses and results provide the foundation for management strategies for the conservation of ecological processes and biodiversity in both countries

Study Area

Information Compilation

Land Use and Vegetation Cover Information Standardization

LUVC Change and Fragmentation Analyses

Results and Discussion

Conclusions