The Twangiza mine is located in the Mitumba mountain range, in the western part of the Albertine Rift Valley, just 20 km East of Itombwe Nature Reserve. A biological inventory was carried out within the mine’s decade...The Twangiza mine is located in the Mitumba mountain range, in the western part of the Albertine Rift Valley, just 20 km East of Itombwe Nature Reserve. A biological inventory was carried out within the mine’s decade-old progressive ecological rehabilitation sites. This inventory covered insects, amphibians, reptiles, birds and small mammals. The main objective of the inventory was to assess the level of animal recolonization in the 100-hectares’ restored areas. A total of 22 insect genera, 4 amphibian species, 11 reptile species, 43 bird species and 11 small mammal species were found. All of them were strongly settled in the core area within the afforested sites. Prior to the start of the Twangiza mine activities and 4 years before the ecological rehabilitation in the area, the avifauna was depauperate, both in number of species and their abundance. By then, no mammals or reptiles were recorded within the footprint area. The environmental and social baseline assessment identified 38 bird species in 2008, mainly grassland and mobile species, which were using scrub along valley streams as a refuge, outside the current mine footprint. Our results clearly demonstrate the positive impact of the afforestation on insect, amphibian, reptile, bird and small mammal’s diversity in this area.展开更多
Volcanism is a primary process of land formation.It provides a model for understanding soil-forming processes and the role of pioneer bacteria and/or archaea as early colonizers in those new environments.The objective...Volcanism is a primary process of land formation.It provides a model for understanding soil-forming processes and the role of pioneer bacteria and/or archaea as early colonizers in those new environments.The objective of this study was to identify the microbial communities involved in soil formation.DNA was extracted from soil samples from the Llaima volcano in Chile at sites destroyed by lava in different centuries(1640,1751,and 1957).Bacterial and archaeal 16 S r RNA genes were analyzed using quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing.Results showed that microbial diversity increased with soil age,particularly between the 1751 and 1640 soils.For archaeal communities,Thaumarchaeota was detected in similar abundances in all soils,but Euryarchaeota was rare in the older soils.The analysis of bacterial 16 S r RNA genes showed high abundances of Chloroflexi(37%),Planctomycetes(18%),and Verrucomicrobia(10%)in the youngest soil.Proteobacteria and Acidobacteria were highly abundant in the older soils(16%in 1640 and 15%in 1751 for Acidobacteria;38%in 1640 and 27%in 1751 for Proteobacteria).The microbial profiles in the youngest soils were unusual,with a high abundance of bacteria belonging to the order Ktedonobacterales(Chloroflexi)in the 1957 soil(37%)compared with the 1751(18%)and 1640(7%)soils.In this study,we show that there is a gradual establishment of the microbial community in volcanic soils following an eruption and that specific microbial groups can colonize during the early stages of recovery.展开更多
The regime of disturbance with natural or anthropogenic origin can lead to the destabilization or even to a mass mortality of benthic communities. Due to the heterogeneity of the disturbance there is a formation of pa...The regime of disturbance with natural or anthropogenic origin can lead to the destabilization or even to a mass mortality of benthic communities. Due to the heterogeneity of the disturbance there is a formation of patches in different stages of ecological succession. The aim of this study is to follow and describe the resilience in artificial disturbed sediment in a polluted bay in Rio de Janeiro. The sediment was collected, sterilized and placed inside corers (10 cmdiameter ×15 cmheight) in the same place where it was collected. We allocated the samples in two structures, the difference between them was that one was placed closed to the bottom and the other was placed50 cmheight. We found 2352 organisms distributed in 14 taxons. The class Polychaeta and the order Amphipoda showed the highest density in all the survey and treatments. We identified the factors influencing the scenarium: different mechanisms of dispersal, the position of the structures and life history of each group. Disturbance can be the main cause of the patch’s diversity found in estuaries and coastal areas. Because of this, monitoring of selected areas becomes an important tool to understand the regime of disturbance as a key factor structuring benthic communities in soft sediment, also suggesting a metapopulation dynamics.展开更多
文摘The Twangiza mine is located in the Mitumba mountain range, in the western part of the Albertine Rift Valley, just 20 km East of Itombwe Nature Reserve. A biological inventory was carried out within the mine’s decade-old progressive ecological rehabilitation sites. This inventory covered insects, amphibians, reptiles, birds and small mammals. The main objective of the inventory was to assess the level of animal recolonization in the 100-hectares’ restored areas. A total of 22 insect genera, 4 amphibian species, 11 reptile species, 43 bird species and 11 small mammal species were found. All of them were strongly settled in the core area within the afforested sites. Prior to the start of the Twangiza mine activities and 4 years before the ecological rehabilitation in the area, the avifauna was depauperate, both in number of species and their abundance. By then, no mammals or reptiles were recorded within the footprint area. The environmental and social baseline assessment identified 38 bird species in 2008, mainly grassland and mobile species, which were using scrub along valley streams as a refuge, outside the current mine footprint. Our results clearly demonstrate the positive impact of the afforestation on insect, amphibian, reptile, bird and small mammal’s diversity in this area.
文摘Volcanism is a primary process of land formation.It provides a model for understanding soil-forming processes and the role of pioneer bacteria and/or archaea as early colonizers in those new environments.The objective of this study was to identify the microbial communities involved in soil formation.DNA was extracted from soil samples from the Llaima volcano in Chile at sites destroyed by lava in different centuries(1640,1751,and 1957).Bacterial and archaeal 16 S r RNA genes were analyzed using quantitative polymerase chain reaction(q PCR)and Illumina Mi Seq sequencing.Results showed that microbial diversity increased with soil age,particularly between the 1751 and 1640 soils.For archaeal communities,Thaumarchaeota was detected in similar abundances in all soils,but Euryarchaeota was rare in the older soils.The analysis of bacterial 16 S r RNA genes showed high abundances of Chloroflexi(37%),Planctomycetes(18%),and Verrucomicrobia(10%)in the youngest soil.Proteobacteria and Acidobacteria were highly abundant in the older soils(16%in 1640 and 15%in 1751 for Acidobacteria;38%in 1640 and 27%in 1751 for Proteobacteria).The microbial profiles in the youngest soils were unusual,with a high abundance of bacteria belonging to the order Ktedonobacterales(Chloroflexi)in the 1957 soil(37%)compared with the 1751(18%)and 1640(7%)soils.In this study,we show that there is a gradual establishment of the microbial community in volcanic soils following an eruption and that specific microbial groups can colonize during the early stages of recovery.
文摘The regime of disturbance with natural or anthropogenic origin can lead to the destabilization or even to a mass mortality of benthic communities. Due to the heterogeneity of the disturbance there is a formation of patches in different stages of ecological succession. The aim of this study is to follow and describe the resilience in artificial disturbed sediment in a polluted bay in Rio de Janeiro. The sediment was collected, sterilized and placed inside corers (10 cmdiameter ×15 cmheight) in the same place where it was collected. We allocated the samples in two structures, the difference between them was that one was placed closed to the bottom and the other was placed50 cmheight. We found 2352 organisms distributed in 14 taxons. The class Polychaeta and the order Amphipoda showed the highest density in all the survey and treatments. We identified the factors influencing the scenarium: different mechanisms of dispersal, the position of the structures and life history of each group. Disturbance can be the main cause of the patch’s diversity found in estuaries and coastal areas. Because of this, monitoring of selected areas becomes an important tool to understand the regime of disturbance as a key factor structuring benthic communities in soft sediment, also suggesting a metapopulation dynamics.
