las comunidades de peces del río guadiamar y el accidente minero ...

More documents

Recommendations

Info

Relaciones peces/hábitat en el Guadiamar Omland, 2004). Variance partitioning of the significant variables selected for the general model was performed to identify the most important scale in each case. The potential influence of spatial autocorrelation was tested using a matrix of the reticular distance between all sampling points with each other, and calculating Moran’s I of the residuals of preliminary regressions. Moran’s I value obtained was always 0.05), therefore spatial autocorrelation was unlikely to influence the model results. This analysis was carried out using SAM (Spatial Analyses in Macroecology, Rangel et al., 2006). All other analyses were performed using R version 2.12 and packages: vegan, hier.part, gtools and asbio (R Development Core Team, 2010). In order to assess whether the spill had a relevant influence on species richness and diversity in the Guadiamar River basin eight years after the accident, a binomial variable “Spill” was initially included in models, indicating whether the sampling site was located within the originally affected area (1) or not (0). However, since the spill point is located 5 km downstream from the main reservoir in the Agrio River (Agrio reservoir hereafter), there is an almost complete overlap between the affected area and that influenced by the reservoir, and these two factors are expected to have a negative influence on richness and diversity. In addition, both variables (Spill and Number of reservoirs upstream) are collinear (almost 90%), and only two sampling sites under reservoir influence are upstream from the spill point (Spill = 0). Therefore, the spill influence was assessed using a different approach. Species richness and diversity values downstream from the Agrio reservoir were compared with richness and diversity values downstream of reservoirs from similar watersheds within the Guadalquivir river basin that were not affected by the spill. It was expected that if the spill still exerts a significant influence for the fish community, values from the Guadiamar River basin would be lower than those from other watersheds. For this purpose, data from an ongoing survey carried out for the whole Guadalquivir River basin that uses the same fishing methods (Fernández-Delgado et al., 2010) were used. Six basins with similar reservoirs and environmental characteristics were chosen (Cala, Pintado, Huesna, Montoro, Rumblar and Fernandina) (Fig. 2). Fish richness and diversity data from points located in reaches downstream from the main reservoir in each of these basins were compared with values downstream of the Agrio reservoir using ANOVA. This analysis was also carried out using R 2.12 (R Development Core Team, 2010). 61
Table 1. Selected variables and regression model results for native (-na) and exotic (-ex) fish species richness (S) and diversity (H) at the catchment (_C) and site (_S) scales. The first column shows the variables selected after testing for collinearity. S.E. = standard error, p = probability, Adjusted R 2 = coefficient of determination, Pr(>|t|) = significance. Las comunidades de peces del río Guadiamar y el accidente minero de Aznalcóllar 62
Page 1 and 2:
DEPARTAMENTO DE ZOOLOGÍA UNIVERSID
Page 4 and 5:
DEPARTAMENTO DE ZOOLOGÍA UNIVERSID
Page 6 and 7:
TITULO DE LA TESIS: LAS COMUNIDADES
Page 8:
A mi Madre,
Page 11 and 12:
A mis antiguos compañeros del Grup
Page 13 and 14:
Material and Methods 39 Results 45
Page 15 and 16:
ABSTRACT This PhD Thesis analyzes t
Page 17 and 18:
Las comunidades de peces del río G
Page 19 and 20:
Page 21 and 22:
Page 23 and 24: Las comunidades de peces del río G
Page 25 and 26: ÁREA DE ESTUDIO Cuenca del río Gu
Page 27 and 28: Área de estudio Figura 1. Cuenca d
Page 29 and 30: Área de estudio farallón del Alja
Page 31 and 32: Área de estudio Principales impact
Page 34: PARTE I: Ictiofauna de la cuenca de
Page 48 and 49: II.1- Habitat quality affects the c
Page 50 and 51: Condición somática de L. sclateri
Page 54 and 55: Table 1. Mean habitat variable valu
Page 66 and 67: II.2- Habitat-fish community relati
Page 68 and 69: Relaciones peces/hábitat en el Gua
Page 76 and 77: Figure 2. Tributary network of the
Page 86: PARTE III: Evolución de la comunid
Page 99 and 100: Table 1. List of the fish species c
Page 123 and 124: 110
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
146
Page 161 and 162:
Appendix 1. Environmental variables
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
show all

las comunidades de peces del río guadiamar y el accidente minero ...

Create successful ePaper yourself

Delete template?

Save as template?