 | Zemmrich A. Vegetation-ecological investigations of rangeland ecosystems in Western Mongolia: the assessment of grazing impact at various spatial scale levels: Diss. … Dr. rer. nat. / Ernst-Moritz-Arndt-Universität Greifswald, Mathematisch- Naturwissenschaftliche Fakultät. - Greifswald, 2007. - v, 146 p.: ill., graph. - Ref.: p.132-146.
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1 Introduction ................................................. 1
1.1 Scientific rationale and objectives of the study ........ 1
1.2 The investigation area .................................. 6
1.2.1 Geographical region .............................. 6
1.2.2 Climate .......................................... 7
1.2.3 Soil and vegetation .............................. 9
Desert steppe .................................... 9
Mountain steppe ................................. 11
Alpine belt ..................................... 13
1.2.4 Land use ........................................ 17
2 Vegetation-determining factors along an altitudinal
gradient and their importance for grazing effects - the
landscape level ............................................. 21
2.1 Summary ................................................ 21
2.2 Sampling design ........................................ 21
2.3 Data analysis .......................................... 23
2.4 Technical informations ................................. 27
2.5 Results ................................................ 28
2.5.1 Desert steppe ................................... 28
Vegetation classification ....................... 28
Detrended Correspondence Analysis (DCA
Ordination) ..................................... 37
Principle component analysis (PCA) .............. 39
2.5.2 Mountain steppe ................................. 42
Vegetation classification ....................... 42
Detrended Correspondence Analysis (DCA
Ordination) ..................................... 50
Principle component analysis (PCA) .............. 52
2.5.3 Alpine vegetation ............................... 54
Vegetation classification ....................... 54
Detrended Correspondence Analysis (DCA
Ordination) ..................................... 65
Principle component analysis (PCA) .............. 68
2.6 Discussion ............................................. 69
2.6.1 Desert steppe ................................... 69
Response of desert steppe to grazing ............ 78
2.6.2 Mountain steppe ................................. 79
Response of mountain steppe to grazing .......... 87
2.6.3 Alpine vegetation ............................... 88
Response of alpine belt to grazing .............. 97
2.7 Synopsis of results in the framework of concepts
from vegetation ecology ................................ 97
2.7.1 Orientation ..................................... 97
2.7.2 Vegetation-determining factors and their
alteration along the altitudinal belt ........... 98
2.7.3 The role of competition as vegetation-
determing factor ............................... 100
2.7.4 Grazing effects along the altitudinal belt ..... 101
2.7.5 The role of herbivory as vegetation-
determining factor ............................. 104
2.7.6 The role of competition and herbivory as
vegetation-determining factors in the
examined ecosystems ............................ 108
2.8 Conclusions in consideration of climatic, ecological
and grazing peculiarities of the investigation area ... 109
3 Grazing effects on the population of Artemisia
xerophytica ................................................ 112
3.1 Summary ............................................... 112
3.2 Material and methods .................................. 112
3.2.1 Study material and study area .................. 112
3.2.2 Sampling methods ............................... 116
3.2.3 Soil analysis .................................. 117
3.2.4 Dataanalyes .................................... 117
3.3 Results ............................................... 118
3.3.1 Soil ........................................... 118
3.3.2 Artemisia xerophytica .......................... 119
3.4 Discussion ............................................ 122
4 Synopsis of grazing effects at different spatial scale
levels in the desert steppe ................................ 124
4.1 Summary ............................................... 124
4.2 Material and methods .................................. 124
4.2.1 Study area ..................................... 124
4.2.2 Sampling methods ............................... 125
4.3 Results ............................................... 126
4.3.1 Landscape level ................................ 126
4.3.2 Community level ................................ 126
4.3.3 Population level ............................... 128
4.4 Discussion and conclusions ........................... 129
5 References ................................................. 132
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