A Hierarchical Ecosystem Approach to Evaluate Global Warming Impacts in Three Global Ecoregions

Abstract

Global warming has substantial effects on terrestrial ecosystems in the different Ecoregions. A hierarchical ecosystem approach was conducted to analyze global warming influences with global warming impacts on the three distinct global ecoregions. The ecosystem classification of land (ECL) has been developed and integrated as a hierarchical system. Recently, the hierarchical ecosystem classifications in 300 Dry Domain of the United States, 100 Polar Domain of Canada, and 500 Plateau Domain of China were demonstrated and explored in studying the environmental system changes and global warming impacts. This article tries to present the distinctive dissimilarity in each ecoregion and demonstrate the ecosystem responses linked to the hierarchical ecosystem structure and ecological function level. 1) In the Dry Domain, the warmer and wetter of Utah’s climate gave rise to Rocky Mountain subalpine conifer forests and Great Basin pinyon and juniper woodlands suitable for growing, which correspond to their Utah’s Climate life zone, and are affiliated with the Middle levels of ECL ( U7 up to U4). Conversely, in a warmer and drier of Utah’s climate, annual plant species and invaded species shifted and expanded at the lower levels of ECL (U10 up to U9). 2) In the Polar Domain, a warmer and wetter winter of Yokon climate influence the Spruce treeline moving northward and to higher elevations, as well as for the arctic tundra and alpine tundra. Arboreal species grow fast to reach fructification. These are typically appeared in the middle levels of ECL (Y8 up to Y5) and changed the carbon budget to a carbon sink (Y4 up to Y2). With a warmer and drier summer, Shrubification in Yukon is happening rapidly (Y6 up to Y5 ). Potentilla shrub and Salix shrub expand to the arctic tundra region. 3) In the Plateau Domain, an annual air temperature increases by 0.5o C/10y over the last 45 years, and the temperature fluctuations have significantly affected the essential changes in the global energy balance and carbon budget in the upper levels of ECL (Q4 up to Q1). However, the precipitation showed no noticeable difference. The alpine tundra vegetation simulated by the Vegetation Dynamic Simulation Model (VDSM) integrated with scenarios of a global temperature increase of 1 to 3°C. It illustrated the vegetation biomass changes in the lower levels to middle levels of ECL (Q8 up to Q6 ) and the vegetation distribution dynamics had appeared in upper levels of ECL ( Q4 up to Q1) .

Improving Hierarchical Ecosystem Structures and Multicriteria Evaluation for Current Land Ecosystem Classification

“…The lower-level LECs can be created in ArcGIS software efficiently when high resolution DEM is available. The Ecological Sites/Ecosites can be objectively defined at the bottom level (West et al 2005;Paul et al 2018;Zhang and Zhou 2022). In this study, there was a lack of plant species commonly shared between Y8 and U9 ecoregions.…”

“…Unique focal level ecosystems can be identified based on climate, landform, hydrology, and bioclimatic features. Habitats found in the Dry Domain are not interchangeable with those in the Polar Domain (Zhang and Zhou 2022). This finding has significant implications for understanding how ecosystems respond to global warming impacts.…”

“…This finding has significant implications for understanding how ecosystems respond to global warming impacts. It emphasizes that species adapted to specific ecosystems cannot survive in drastically different environments, and invading species must come from similar ecosystems or habitats (Zhang and Zhou 2022).…”

“…One of Yukon Ecosites was identified as the climax community Lodgepole Pine Spruce-Grass-Lichen (Table 2). To differentiate between regional ecosystems at the bottom level, there is a lack of plant species that are commonly shared (West et al 2005;Zhang and West 2022;Zhang and Zhou 2022). As a result, when a comparison was made between the Ecological sites/Ecosites of the two ecosystems, the pH values were chosen as a component in the E [i, j] matrix.…”

Improving Hierarchical Ecosystem Structures and Multicriteria Evaluations for Current Land Ecosystem Classification

“…Unique ecosystems can be identi ed based on climate, landform, hydrology, and bioclimatic features. Habitats found in the Dry Domain are not interchangeable with those in the Polar Domain(Zhang et al 2022). This nding has signi cant implications for understanding how ecosystems respond to global warming impacts.…”