NBR NBR Cianeto The NBR prompted the ABNT (Brazilian Association for Technical Standardization) to produce eleven. Buy NBR ELABORACAO E APRESENTACAO DE PROJETO DE REABILITACAO DE AREAS DEGRADADAS PELA MINERACAO from SAI Global. ABNT NBR pdf. Uploaded by. paulolimad Nbr Elaboracao E Apresentacao de Projeto de Reabilit. Uploaded by. paulolimad.
|Published (Last):||20 June 2015|
|PDF File Size:||4.67 Mb|
|ePub File Size:||11.7 Mb|
|Price:||Free* [*Free Regsitration Required]|
Unexpected effects of pigeon-peas Cajanus cajan in the restoration of rupestrian fields. I,II ; Castro, S. III ; Ker, F. I ; Fernandes, G I.
Restoration by planting the legume Cajanus cajan was implemented in some of these areas. The present study compares plant species richness, diversity, abundance, nbbr, similarity, and soil composition between restored and non-restored areas, in an attempt to evaluate the effectiveness of the use of C.
Each treatment restored and non-restored had four sampling areas, each with three 130030 2 plots. We counted and identified every individual plant found within these plots. We also collected soil from the superficial layer cm of each sampling area in both treatments. The areas where C. The soil of nrb areas also contained higher levels of Phosphorus and Magnesium. Contrary avnt the expectations, soil enhancement in the quartzitic abht poor in nutrients in the rupestrian fields can facilitate the invasion by exotic plants, which are not adapted to the lack of nutrients.
As it appears, the use of C. The rupestrian fields of the southeastern Brazil are composed of a mosaic of vegetation types, from which we barely know the number of species and some natural history.
The steady increase in human activity within this region has impacted this ecosystem in recent decades. Impacts originating from mining, road construction, pasture establishment, tourism, and periodic fires, have been the main source of soil erosion, species extinction, and alien species invasion Viana et al. However, most initiatives to restore degraded areas have been using methods that do not follow this definition strictly.
In most cases, exotic species are used with consequences to ecosystem processes and functioning not fully evaluated. This highway was restored in and the pigeon pea, Cajanus cajan Fabaceaewas used to facilitate the succession process.
The species has its origins in India Provazi et al. Ultimately, better nutrient mobilization would enhance plant growth and performance, hence leading to faster and larger vegetation cover. Ignoring this fact, environmental agencies have broadly allowed the use of exotic species, despite awareness of the impacts of invasive species on local flora and associated fauna.
In spite of the scientific arguments that the use of C.
The environmental agencies involved allowed the use of a mix of species containing many exotic species that were spread into the region by hydro-seeding, when previous studies had advised the use of only native species Ribeiro et al. The justification to use C. However, several years after its introduction, casual observations indicated that C.
Therefore, the goal of this study is to provide empirical data on the effects of using C. The region is characterized by mesothermic climate, with dry winters and wet summers. Mean temperature ranges from Elevation at the studied sites averages meters. All monitored areas were located from five to fifty meters from the road. Out of the eight chosen areas, four were previously restored through the planting of C. Restored and non-restored areas were located at a minimum of m to a maximum of 3.
In each of these areas, three plots of 5 x 5 meter totalizing m 2 for each treatment were randomly chosen. All plant individuals except grasses within the plots were counted and identified.
We analyzed the number of plant species richnessplant diversity Shannon index Niklaus et al. In addition, we compared the area similarity comparing plots through Jaccard index Ricklefs, within both treatments.
To test the influence of C. Each sample was composed of soil from the superficial layer maximum depth: As some data did not present normal distribution and variance homogeneity, we used the Mann-Whitney test to compare diversity, species richness, equitability, plant abundance, and soil traits.
To evaluate the influence of Phosphorus and Magnesium on the plant abundance and species richness we used a Pearson correlation Zar, Cajanus cajan density within the restored areas was 4. The older individuals of C. Species richness and plant abundance were 2. Likewise, diversity was 1. Equitability did not differ significantly between the restored and non-restored sites Table 1.
Similarity was small and varied from 0 to 0. On the other hand, none of the other soil components analyzed differed statistically between the two treatments Table 2.
When only the areas restored with C. The data presented here shows that the restoration program using the exotic species C. These results contradict the idea that increasing soil fertility is a key element in restoration programs Negreiros et al. Perhaps, the use of alien sun-plants in forest ecosystems would have reduced impacts in the community, as it is expected that these species became extinct as the native trees grow.
Casual observations indicate that under larger density, C. Under such 1030 scenario, C. Although the amount of organic matter was not analyzed in the present study, the abnnt of nitrogen between the two treatments did not differ statistically.
The quantity of magnesium found in this study was lower than that reported by Marques et al. The level of Phosphorus found in the restored areas was higher then the level reported by Marques sbnt Negreiros et al.
The higher amount of Phosphorus in the soil must also be related to the elevated litter formation in the areas where C. The disturbance of a system through species introduction, biomass input, or manuring can lead to higher levels of Phosphorus mineralization due to an increase in the microbial activity Gatiboni et al. In addition, abny procedures are generally associated with calcium and phosphate input Embrapa,which can also explain the higher amount of phosphorus in the areas where C.
After fertilization, the inorganic forms of phosphorus increase due to its accumulation in the soil Grant et al.
nbr 14063 1998
The phenomenon was explained by the paving process, which uses a substance rich in CaCO 3 that would promote an increase in pH along the road side. In fact, we found high pH levels in both treatments. Rupestrian field soils are generally acidic, poor in nutrients, and contain high Aluminum saturation values due to geological and geomorphological conditions Benites et al. Despite the higher concentration of phosphorus, the presence of C. Even if the nutrient increase that resulted from the presence of C.
Fertilization can enhance the growth rate of plants during restoration processes, but can also promote competitive exclusion of some species Lawrence, Indeed, Tilman found a negative correlation between species richness and soil fertilization while Negreiros et al.
Natural tropical ecosystems are formed by numerous types of vegetation in which species composition and selective pressures imposed by both, biotic and abiotic factors, may be singular. Restoration must take into account previous knowledge and idiosyncrasies of each vegetation and site.
The perception that cocktails of species can be widely used in restoration and that the use of exotic Fabaceae does not represent risks to the succession process is misleading. The observations we present here, together with those reported by Negreiros et al. The introduction of exotic species is one of the main causes of the current mass extinction of species Mittermeier et al.
In conclusion, the use of C. Although equitability, similarity between plots, and some soil components did not vary between treatments, the restoration project reduced plant diversity and abundance in the areas examined.
Deeper understanding of the role of commonly used practices and exotic species in the restoration of Brazilian vegetation is urgently needed because tropical vegetations present different species composition structure and functional properties. We also would like to thank the Reserva Natural Vellozia for logistical support; to C. Barbosa for suggestions and commentaries. Distribution of non-native invasive species and soil properties in proximity to paved roads and unpaved roads in a quartzitic mountainous grassland of southeastern Brazil rupestrian fields.
Centres of plant diversity: World Wide Fund For Nature, Disturbance, diversity, and invasion: The response of tropical tree seedlings to nutrient supply: Seedling growth and biomass allocation of endemic and threatened shrubs of rupestrian fields. A long-term field study on biodiversity X elevated CO 2 interactions in grassland. Mycorrhizal inoculation effect on nodulation and N accumulation in Cajanus cajan at soil P concentrations sufficient or inadequate for mycorrhiza-free growth.
Botanical description of selected pigeonpea pure lines. Patterns of abundance of a narrow endemic species in a tropical and infertile montane habitat.
Unexpected effects of pigeon-peas (Cajanus cajan) in the restoration of rupestrian fields
A economia da natureza. Secondary succession and the pattern of plant dominance along experimental nitrogen gradients. Ecological road threatens endemic Brazilian plant with extinction.