The Review of Two Cases of Upper-Level Ecosystem Classification of Land
1. Upper-Level Ecoregions between the United States and China
The ecosystem can be a complex system, which is changed and varied along with longitude, latitude, and elevation on the earth surface, and always adapted to the slop, and aspect and environmental variables in macroscales (Allen et al., 2014; Brodrick et al., 2019). Bailey (1995, 1996) had made his contributions on mapping the ecoregions of the United States, North America, and world continents. Theoretically, Bailey’s Ecosystem Classification had explained the ecoregions and their nested structures in the upper levels of Domain, Division, and Province.
Zheng (1999) and Wu et al. (2003) compared the ecosystem classification between China and the United States. Since they used the temperatures, water conditions, and landforms for the upper level of ECLs, there were similarities between these two ECLs. However, there were some failures to match each level class among the top three levels. At the top levels, China ECLs mainly used the accumulated temperature and the days of great than 100C,and next level used aridity to classify as humid, dub-humid, semiarid, and arid (Labeled as A, B, C, D separately) and used landform types to classify plain, mountain and hills (Labeled as 1, 2, 3…etc.).
China’s ecological geographic ecoregions had been classified and named (Table 1). For example, IIB1 for the CentralSonhLiao Plain, IIB3 for Piedmont Plain & Hills of Sanhe, HIB for High Plateau of Golog_ Nagqu, HIIA/B for High Mountains and Gorges of W. Sichuan and E. Xizang, etc.
Relatively, China's Eco-geographic classification is mostly fitted into Bailey’s Ecosystem Classification regime, and represents the top level of Eco-geographic regions for their scientific needs. Zheng (1999) and Wu et al. (2003) had provided the theory analysis and delineated the boundaries for 11 eco-geographic zones. The HI and HII eco-geographic zone in China did not properly fit into any domain developed by Bailey. Bailey (1995, 1996) initially had put HI and HII area into his framework as M310 Tropical /subtropical Steppe Regime Mountains, and M320 Tropical /subtropical Desert Regime Mountain. Thus, Zheng and Wu et al. left an empty entity for the Domain to which HI and HII eco-geographic zones should have belonged.
Table 1
Upper Level Ecoregions of China and Bailey’s ECL
Bailey’s ECL
|
Domain
|
Division
|
Province
|
China eco-geographic regions
|
US and China
|
200 Humid Temperate Domain
|
230 Subtropical Division
|
M230 Subtropical Regime Mountains
|
VI.South Subtropical Zone
|
250 Prairie Division
|
M250 Prairie Regime Mountains
|
I.Cold Temperate Zone
|
300 Dry Domain
|
310 Tropical /subtropical Steppe Regime Division
|
M310 Tropical /subtropical Steppe Regime Mountains
|
V.Middle Subtropical Zone
|
320 Tropical /subtropical Desert Division
|
M320 Tropical /subtropical Desert Regime Mountain
|
IV.North Subtropical Zone
|
330
Temperate Stepper Division
|
M330 Temperate Steppe Regime Mountain
|
II.Medium Temperte
Zone
|
340 Temperate Desert Division
|
M340 Temperate Desert Regime Mountains
|
III.Warm Temperate Zone
|
400 Humid Tropical Domain
|
410 Savana
Domain
|
M410 Savana Regime Mountains
|
VII.Marginal Tropical Zone
|
420 Rainforest
Division
|
M420 Rainforest Regime Mountains
|
VIII.Middle Tropical Zone
IX.Equator Tropical Zone
|
500 Plateau Domain
|
510 Plateau Sub-Polar Division
|
Provinces of
HIA Humid
HIB Semi-humid
HIC Semiarid
HID Arid
|
HI.Plateau Sub-Polar Zone
|
520 Plateau Temperate Division
|
Provinces of
HIIA Humid
HIIB Semi-humid
HIIC Semiarid
HIID Arid
|
HII. Plateau Temperate Zone
|
Relatively, China's Eco-geographic classification is mostly fitted into Bailey’s Ecosystem Classification regime, and represents the top level of Eco-geographic regions for their scientific needs. Zheng (1999) and Wu et al. (2003) had provided the theory analysis and delineated the boundaries for 11 eco-geographic zones. The HI and HII eco-geographic zone in China did not properly fit into any domain developed by Bailey. Bailey (1995, 1996) initially had put HI and HII area into his framework as M310 Tropical /subtropical Steppe Regime Mountains, and M320 Tropical /subtropical Desert Regime Mountain. Thus, Zheng and Wu et al. left an empty entity for the Domain to which HI and HII eco-geographic zones should have belonged.
The Domain Plateau was predicted by a binary domain decision tree in Fig. 1, and it was comparable with Domain Arctic and Domain Tropic. This Domain classification solved the problems about the tropical and subtropical regions have sub-polar and temperate zones in the high elevation plateau and mountains regimes. The HI and HII eco-geographic zones were delineated (Zheng 1999) and named as the Plateau Sub-polar Division and Plateau Temperate Division separately. The HI was classified with further lower level provinces of HIB: Hilly Plateau of Golog-Nagqu Sub-humid Province, HIC: Plateau with Broad Valley Semiarid Province, HID: Kunlun Mountains & Plateau Arid Province. The HII was classified with further lower level provinces of HIIA/B: High Mountains of Gorges of W. Sichuan and E. Xizang Humid & Semi-humid Province, HIIC: Plateau & Mountains Semiarid Province (E. of Qinghai, Qilian Mountains, and S. Xizang), HIID: Qaidam Basin and N. Slopes of Kunlun Mountains and Ngari Mountains Arid Province in the Table 1.
Based on Bailey’s (1995), the next level classification is the Section based on mesoscale of landforms such as basin, watershed, and mountain terrain shape, pattern, geologic substratum, and geologic structure and scales. China’s ECLs used the plains, hills, and mountains to classify, or equivalent to Bailey’s Sections, which are being named with numeric numbers 1,2, and 3 such as HIB1, HIC1, HIC2, HID1, and HIIA/B1, HIIC1, HIIC2, HIID1, HIID2, HIID3. Theoretically, the predicted HI and HII with A, B, C, D, and intermediate types A/B can exist in the system in the Table 1.
The Analysis of Three Cases of Lower-Level Ecosystem Classification of Land
1. The Study on Lower-Level Ecosystem Classification in United States
Ecoregions of the United States had been examined by Bailey (1995,1996) in great detail at Domain, division, and Province. The first case study used for lower-level was accomplished with upper 4 levels for the project in a 4.5-million-hectare area centered in western of ECOMAP (1993). National Hierarchy of Ecological Unit (NHEU) had been set up to present as the coarsest boundaries Utah, the United States. This project started in 1995, and conducted out in a team works. It stressed one of 300 Dry dominant; Divisions area had bounders intersecting with 340 Temperate Desert Division and M340 Temperate Desert Regime Mountains Divisions; three provinces are interesting with study area, 342 Intermountain Semi-Desert Province, M341 Nevada-Utah Mountains Semi-desert Coniferous Forest Alpine Province, and 341 Intermountain Semi-Desert and Desert Province. The study area is intersecting with 4 sections, Bonneville Basin Section, Central Great Basin Section and Northeastern Great Basin Section, and Northwestern Basin and Range Section. In the Table 2, 8 levels’ ECOMAP Units were applied to the study area as the outline of ecosystem classification, and the rules and ecological features for the ECL model (Fig. 3A).
Table 2
Summary of the bases of ecosystem classification layers for the Hill AFB project
Level
|
ECOMAP Name
|
Example name
|
Main Environmental
Characters
|
Data Source & methods
|
Scales
|
1
|
Domain
|
300 Dry
|
Climate
|
Köppen Bsk
|
Ecoregion
|
2
|
Division
|
340 Dry Temperate
|
Climate
|
Bsk
|
Ecoregion
|
3
|
Province
|
342 Intermountain Semi-Desert
|
Climate
|
Bsk
|
Ecoregion
|
4
|
Section
|
Central Great basin
|
Topography
|
Terrain
|
Segment
|
5
|
Subsection
|
Erosional landscape, East slope of grassy Mountains
|
Intermediate scale terrain segment
|
Terrain segment
|
Landscape mosaic
|
6
|
Landtype Association
|
Moderately hard sedimentary erosional landscape
|
Macroterrain
Units,
|
Erosional, depositional landscape
|
Landscape mosaic
|
7
|
Landtype
|
Alluvium, eolian sediments
|
Mesottrain units
|
Soil type of rock, sedimentary, lake, glacial, volcanic
|
Landscape mosaic
|
8
|
Landtype Phases
|
Moderately hard sedimentary (ridge, middle, foot slope)
|
Microterrain units
|
Landform (side, toe, foot, bottom) and moisture regime
|
Ecozone/zone
|
9
|
Ecological Sites
|
Desert Loam
|
Objectively defined land unit
|
Evaluation and management
|
Sites
|
10
|
Vegetation Stands
|
Desert Loam
|
Homogeneous vegetation
|
Vegetation association
|
Stands
|
Note: Ecoregion, Ecozone means the classification classes had both biotic and abiotic features |
“Bolson” is subsection and used as a special term in the lower level of ecosystem classification, described the terrain. DEM data (30m) was used in the model and generated 60 bolson segments (Fig. 2B). In the study area, the macrotterain, mesoterrain, microterrain units were generated in the model with algorisms to identify and delineate their boundaries. The protocols (Fig. 3A) were used to identify landscape units between ladtype association, landtype, and lantype phase one step at a time seperately. The ecological sites (ESs), the 9th level, was designed to overcome the using important data on ESs, nested to ECOMAP; vegetation stands (VSs), the 10th and finest-grain level were subdivisions of individual polygons of ESs (Fig. 3B) based on differences in disturbance histories that have led to differing current vegetation structure and composition. The vegetation stands were defined and described in terms of vegetation characteristics that represent fine-scale variations in regional climate, site-specific moisture, nutrient regimes, and disturbance histories (fire, grazing and human activities).
2. The Study on Lower-Level of Ecosystem Classification of Land in China
In our second study case, Qinghai province is located western China, and the northeast part of Qinghai-Tibet Plateau. The latitude is from 31039’N to 39011’N, and the longitude is from 89025’E to 103004’E. From south to north, there is almost a span of 8 degrees that equates to 800 km, and from east to west, there is a span of more than 14 degrees that equates to 1200 km (Zhou and Wang et al., 1987). The total area of Qinghai province is 720,000 km2.
Qinghai province is far away from the east-south coast of Mainland China, where the summer monsoon comes from the Pacific Ocean and brings the rainfall to the China continent. The warm and wet air mass only reaches the southeast province boundary and leaves the west part of the area dry in summer and cold in the winter. Geographically, Qinghai province is located in the subtropical and warm-temperate climate zone. However, the average elevation of the province is increased over 3000 m above sea level and the subtropical zone’s evergreen broad-leaved forest and warm-temperate zone’s deciduous broad-leaved forest are total disappeared and replaced by the alpine shrub, alpine tundra, alpine steppe, and alpine desert vegetation. The annual average temperature in the coldest month is under − 6.5OC in the whole province, and the annual average temperature in the warmest month is under 10OC in higher mountain region (> 3500m), 10OC-15OC for the valleys and mountain slop (2700 m -3500 m), above 15OC in east agriculture region and west desert basin. The rainfall is in the summer season during June, July, and August, taking by 80–90% of annual total precipitation. Qilian Mountain ridge is divided north border from Gansu Province. Qaidam bison located in the northwest of the province, basin valley elevation is about 2600 m, the north border with Altyn-Tagh mountain range. Southern Qinghai Plateau is named for the southern area of Golog Mountains and Qinghai South Mountains, and the northern area of Tangula Mountains, which form major higher plateau in Qinghai (Fig. 4 (a)).
The Qinghai province is within the 500 Plateau Domain as we examined and defined, intersected with the HI, Plateau Sub-polar Division and HII, Plateau temperate Division (Fig. 3 (b)). The Qinghai province region is intersecting with 5 Sections in Table 3.
Table 3
Biogeoclimatic Framework and lower-levels’ ECLs in the North East Qinghai Province in China
HIC1: Plateau with Broad Valley Semiarid Section
i QingNan Plateau cold temperate coniferous forest, alpine shrub, alpine tundra Subsection
|
HIIC1: Plateau & Mountains Semiarid Section (E. of Qinghai, Qilian Mountains)
i. Qinghai East-North Alpine Tundra Subsection and QingNan Plateau West Steppe Subsection
i a QingHai East-North temperate Steppe ecozone
ia-1 HuangShui River watershed Forest, Temperate Steppe zone
ii QiLian Mountain East Alpine Shrub and Alpine Tundra subsection
iia QiLian Mountain East Alpine Shrub and Alpine Tundra ecozone
iia-1 Da-Tong River-Black River Alpine Shrub, Alpine Tundra zone
iia-2 Lake Around Alpine Shrub, Alpine Tundra zone
|
HIID 1, 2: Qaidam Basin and N. Slopes of Kunlun Mountains, and Ngari Mountains Arid Section
|
HIB1 Hilly Plateau of Golog-Nagqu Sub-humid Section
|
HID1: Kunlun Mountains & Plateau Arid Section
|
With considering the upper levels’ ecosystem classification in China, the lower-levels’ ecosystem classification in Qinghai province was conducted and classified, showing at Table 3 and Fig. 5. Based on the biogeoclimate condition, vegetation distribution, landform, and plant species feature, three level biogeoclimate classifications under Section were created, for example top layers i., ii., and 3 lower-levels’ hierarchies of Subsection, Ecozone, and zone when applying ECOMAP classification framework.
Using DEM data and spatial analysis model (Zhang and Peterman et al., 2008), the lowest level of the ecological sites were classified, which was based on vegetation type, slope or aspect position (Fig. 5A).
By using objectively defined algorism, the ecological sites map in the area of Haibei Alpine Meadow Ecosystem Station was generated. The map scales was changed from 1:3,000,000 (Subsection, ecozone, and zone) to 1:50,000 in mapping Ecological Sites. With the development in the GIS spatial analysis model ( Zhang et al., 2008), the Normalised temperature surface was generalized and integrated in the Vegetation Dynamic Simulation Model (VDMS). We simulated the alpine tundra vegetation dynamics in response to global warming with scenarios of global annual mean temperature increase of 1o to 3oC. Since the study area was with the features of the plain, lower hills, and glacier mountains, the ecological sites showed the relation with elevation, slope, aspect, temperature, and water condition (Table 4) ( Zhang et al 2008). This approach had been demonstrated, and applicable to the entire region of Qinghai-Tibet Plateau in China (Zhang and Sun et al., 2010) in the simulation of alpine tundra dynamics in response to the global warming.
Table 4
Haibei Ecological Sites’ Soil Temperature, Soil Potential, aspect, and elevation range
Ecological Sites
|
N0. Of Layers
|
Slope
|
Elevation range
m
|
Soil temp
10 cm
|
Soil potential (Centibar)
10 cm
|
Coverage
%
|
Wet Potentilla
|
2
|
NE 15o-NW 40o
|
3200–3450
|
11.17
|
-13.97
|
70–80
|
Dry Potentilla
|
2
|
SW 10o-25o
|
3300–3650
|
10.40
|
-20.00
|
80–90
|
Typical Kobresia
|
1
|
Flat
|
3200–3250
|
12.40
|
-12.10
|
90–95
|
Dry Kobresia
|
1
|
SE20o-SW40o
|
3200–3300
|
15.15
|
-21.00
|
80–90
|
Wet Kobresia
|
1
|
SW30o-W 0o
|
3200–3350
|
11.20
|
-18.00
|
80–85
|
Riverside Blusmus
|
1
|
Flat
|
3100–3140
|
13.50
|
0.00
|
90–95
|
Riverside Kobresian
|
1
|
Flat
|
3100–3200
|
9.80
|
-4.00
|
90–95
|