Section IV: Ecosystem Monitoring

41

Altitudinal Belts: Global Mountains, Patterns, and Mechanisms

Introduction..................................................................................................339

Global Altitudinal Belts: Diversity and Complexity................................341

Patterns of Altitudinal Belts........................................................................341

From High to Low Latitudes • From Coastal to Inland Areas of Continents • From the Outer Margins to the Interior of Mountain Massifs • Difference between Shady and Sunny Slopes and between Windward and Leeward Slopes • The Upward Shifting of Altitudinal Belts with Global Warming

Baiping Zhang Mechanisms for the Pattern of Altitudinal Belts......................................343

Chinese Academy Latitude • Continentality vs. Isolation • Mass Elevation Effect vs. Summit

of Sciences '

Syndrome • Physiological Factors • Key Bioclimatic Indexes

Fang Zhao Conclusions...................................................................................................345

Henan University References......................................................................................................345

Introduction

This entry is to show the diversity and complexity of global altitudinal belts, their basic patterns, and the main mechanisms. The mountains of the world are characterized by numerous and colorful altitudinal vegetation belts and their local-specific combination from mountain base upwards to mountain top (i.e., spectra of altitudinal belts, Figure 41.1), thanks to the extremely high degree of three-dimensional differentiation and heterogeneity of landscapes and the whole environment. On the one hand, these belts follow a general trend of ascending from polar to tropical regions, from island to continental inland, and from the periphery to central parts of large mountain massifs; on the other hand, local factors (geo- morphic, human, and soil factors; and even ocean currents, species competition, beetle infestations, invasive pathogens, and even herbivores) could distort the general trend of global-scale distribution and modify the altitudinal limits of these belts to varying degrees. In other words, global and local factors interplay to shape the actual distribution of altitudinal belts. The most prominent and ever taken-for- granted phenomenon is that the latitudinal distribution of treelines and snowlines actually takes on a subtropical/dry tropical double humps with a tropical depression [1,2], and this was ever justified with low seasonal variation of temperature and the consequential lack of “summer heat” during the growing season [3-5]. But the hidden root or geographic factor forming these two humps (at 30°N and 20°S, respectively) has not been revealed. To scientifically illuminate the formation of the two humps can greatly promote the study of global patterns and mechanisms of altitudinal belts and the understanding of extremely high complexity of the ecological world.

(See color insert.) Representative spectra of altitudinal belts of the global main mountain ranges

FIGURE 41.1 (See color insert.) Representative spectra of altitudinal belts of the global main mountain ranges.

This chapter comprehensively introduces and considers mass elevation effect (MEE) as the main driving factor for the distribution pattern of global altitudinal belts. The conceptual and numerical models of MEE are developed for the main mountain ranges of the world, including the Tibetan Plateau, the Alps, Scandinavian Mts., the Rocky Mts., the Andes, and New Zealand Mts. This can help greatly promote the study of global altitudinal belts and ecological complexity.

 
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