Community dynamics and development of soft bottom macrozoobenthos in the German Bight (North Sea) 1969 - 2000 [Elektronische Ressource] = Dynamik und Entwicklung makrozoobenthischer Weichbodengemeinschaften in der Deutschen Bucht (Nordsee) 1969 - 2000 / Alexander Schroeder

Aschroed

Sujets

• Biologie

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2004
• Nombre de lectures: 20
• Langue: Deutsch
• Poids de l'ouvrage: 8 Mo

Extrait

Community dynamics and development
of soft bottom macrozoobenthos
in the German Bight (North Sea)
1969 - 2000

Dynamik und Entwicklung
makrozoobenthischer Weichbodengemeinschaften
in der Deutschen Bucht (Nordsee)
1969 - 2000

55°
54°
6° 7° 8° 9°

Dissertation zur Erlangung des Grades eines
Doktors der Naturwissenschaften (Dr. rer. nat.)

vorgelegt dem Fachbereich 2 (Biologie & Chemie)
der Universität Bremen


Alexander Schroeder
Bremen 2003 Aus dem
Alfred-Wegener-Institut für Polar- und Meeresforschung
Bremerhaven
























1. Gutachter: Prof. Dr. W.E. Arntz
2. Gutachter: Dr. R. Knust Contents
Zusammenfassung ................................................................................................................ I
Summary.................................................................................................................................. III
1. Introduction...................................................................................................................... 1
2. The German Bight (North Sea)................................................................................. 5
2.1 Topography..................................................................................................................... 5
2.2 Climate............................................................................................................................. 5
2.3 Hydrography ................................................................................................................... 6
2.4 Sediments........................................................................................................................ 7
2.5 Benthic fauna.................................................................................................................. 8
3. Methods ........................................................................................................................... 11
3.1 Long term stations ....................................................................................................... 11
3.2 Benthos data................................................................................................................. 12
3.2.1 Sampling methodology................................................................................................ 12
3.2.2 Sample processing...................................................................................................... 13
3.2.3 Data sources ............................................................................................................... 14
3.2.4 Data quality control...................................................................................................... 15
3.2.5 Data selection for the long-term study......................................................................... 15
3.2.6 Spatial sampling .......................................................................................................... 16
3.3 Environmental data 17
3.4 Analytical methods 18
3.4.1 Indices ......................................................................................................................... 18
3.4.1.1 Spatial distribution & variability ............................................................................... 18
3.4.1.2 Diversity .................................................................................................................. 20
3.4.1.3 Multivariate similarity............................................................................................... 23
3.4.2 Multivariate analytical procedures 24
3.4.2.1 MDS ........................................................................................................................ 24
3.4.2.2 Cluster Analysis ...................................................................................................... 25
3.4.3 Statistical tests............................................................................................................. 26
3.4.3.1 Comparison of univariate measures....................................................................... 26
3.4.3.2 Correlations............................................................................................................. 26
3.4.3.3 Smoothing of time series ........................................................................................ 26
3.4.3.4 Multivariate differences........................................................................................... 27
3.4.3.5 Comparing multivariate pattern between stations .................................................. 27
3.4.3.6 Multivariate Mantel correlograms............................................................................ 27
3.4.3.7 Multiple statistical test............................................................................................. 28
3.4.4 Analysis of spatial variability 29
3.4.5 Samples size dependence .......................................................................................... 30
3.4.6 Temporal community development ............................................................................. 31
3.4.7 Environmental influences ............................................................................................ 32 4. Results ............................................................................................................................. 33
4.1 Precision of sampling position ................................................................................... 33
4.2 Spatial variability .......................................................................................................... 34
4.2.1 Spatial structuring........................................................................................................ 34
4.2.1.1 Gradients................................................................................................................. 35
4.2.1.1.1 Community composition ................................................................................................. 35
4.2.1.1.2 Sum parameter....... 36
4.2.2 Benthic community composition.................................................................................. 37
4.2.2.1 SSd......................................................................................................................... 37
4.2.2.2 WB.......................................................................................................................... 38
4.2.2.3 Slt........ 40
4.2.2.4 FSd...... 41
4.2.3 Precision of quantitative sum parameters ................................................................... 42
4.2.3.1 Sample size influence on density............................................................................ 43
4.2.3.2 Sample sizee on biomass ......................................................................... 44
4.2.4 Community structure and sample size influences....................................................... 45
4.2.4.1 Sample size influence on species number ............................................................. 47
4.2.4.2 Sample size influence on evenness ....................................................................... 51
4.2.4.3 Sample size influence on heterogeneity diversity................................................... 52
4.2.5 Multivariate community similarity................................................................................. 53
4.2.5.2 Sample size influence on multivariate similarity ..................................................... 55
4.2.6 Temporal changes in spatial variability 56
4.3 Methodological changes.............................................................................................. 58
4.3.1 Penetration depth & grab type..................................................................................... 58
4.3.2 Combination of different grabs .................................................................................... 59
4.3.2.1 Univariate measures............................................................................................... 59
4.3.2.2 Inter-sample similarity ............................................................................................. 61
4.3.3 Sampling time.............................................................................................................. 62
4.4 Benthos time series...................................................................................................... 63
4.4.1 Similarity between benthic communities ..................................................................... 63
4.4.2 Similarity of temporal development ............................................................................. 65
4.4.3 Community development at single stations................................................................. 66
4.4.3.1 SSd......................................................................................................................... 66
4.4.3.2 WB.......................................................................................................................... 76
4.4.3.3 Slt........ 85
4.