Climate Change Impacts on Salt Marsh Blue Carbon, Nitrogen and Phosphorous Stocks and Ecosystem Services

Bernardo Duarte,Isabel Caçador,João Carreiras

doi:10.3390/app11041969

Abstract

Salt marshes are valuable ecosystems, as they provide food, shelter, and important nursery areas for fish and macroinvertebrates, and a wide variety of ecosystem services for human populations. These ecosystem services heavily rely on the floristic composition of the salt marshes with different species conferring different service values and different adaptation and resilience capacities towards ecosystem stressors. Blue carbon, nitrogen, and phosphorous stocks are no exception to this, and rely on the interspecific differences in the primary production metabolism and physiological traits. Furthermore, these intrinsic physiological characteristics also modulate the species response to any environmental stressor, such as the ones derived from ongoing global changes. This will heavily shape transitional ecosystem services, with significant changes of the ecosystem value of the salt marshes in terms of cultural, provisioning, regulating, and supporting ecosystem services, with a special emphasis on the possible alterations of the blue carbon, nitrogen, and phosphorous stocks retained in these key environments. Thus, the need to integrate plant physiological characteristics and feedbacks towards the expected climate change-driven stressors becomes evident to accurately estimate the ecosystem services of the salt marsh community, and transfer these fundamental services into economic assets, for a fluid communication of the ecosystems value to stakeholders, decision and policy makers, and environmental management entities.

Highlights

Estuarine and coastal transitional systems are key environments for ecosystem functions
Because the objective of the present paper is to evaluate the different ecosystem services of each transitional system and its changes due to climate change, in the present work all of the areas of each species were combined by summing the coverage area of each species in each water body and analyzed by transitional system
Both of these systems are dominated by H. portulacoides, S. perennis, and S. fruticosa, covering between 78–80% of the surveyed marshes

Summary

Introduction

Estuarine and coastal transitional systems are key environments for ecosystem functions. While only occupying about 4% of total land area and 11% of oceans, they are some of the planet’s most productive ecosystems [1] These systems have attracted human population due to their easy access to natural resources, water-promoted trade, commerce, and waste disposal [2]. Marine angiosperms such as salt marsh communities and seagrasses are of ecological value in coastal environments, forming extensive intertidal or shallow water habitats, providing food, shelter, and important nursery areas for fish and macroinvertebrates [4] Due to these important ecological services provided by salt marsh ecosystems to coastal zones, these systems rank among the most productive and valuable ecosystems on Earth [5]. Salt marshes provide numerous ecosystem services, from coastal protection, flood and storm protection, water purification and flow regulation, air quality, maintenance of fisheries, seafood harvest, habitat/refugia, biological and pest control, carbon and nitrogen sequestration, and nutrient cycling, to recreational, educational, aesthetic, cultural activity, and ornamental setting values [9]

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