Revista Ecologia e Nutrição Florestal - ENFLO

Influence of soil compaction on natural regeneration on a deactivated gravel airstrip in land restoration process

Mon, 25 Nov 2024 00:00:00 -0300

Natural regeneration has been shown to be a good indicator of the state of land restoration. Therefore, this work was carried out with the aim of understanding the floristics and structure of the regenerating plant community and evaluating the influence of soil penetration resistance on the variables diameter, height, density, and basal area of the natural regeneration of shrub-tree species in a degraded area in land restoration process. The study was carried out on a deactivated airstrip in the municipality of Itutinga, MG. To inventory natural regeneration, 19 systematic plots of 5 m x 2 m were launched, totaling a sampling area of 190 m². All shrub or tree species that had a height greater than or equal to 10 cm were surveyed, which were measured in diameter at ground level and in height. The influence of the soil's mechanical resistance to penetration on the diameter, height, density, and basal area of regeneration were calculated using the Pearson Correlation index. The evaluation took place 17 years after reforestation, which was carried out through quincunx planting across the entire area. The regeneration showed satisfactory development and diversity, indicating that forest succession occurs naturally. The diameter and height of regenerating shrub-tree plants were negatively influenced by soil compaction in layers below 40 cm deep. Some species that stand out in growth can be recommended for planting in areas degraded by soil compaction. Deep cross subsoiling is recommended in areas degraded by cutting or filling the soil.

Mixed forest plantation with native and exotic species in a degraded area

Mon, 02 Sep 2024 00:00:00 -0300

Reforestation is the main way to recover degraded areas, and the use of a wide variety of species can assist in the recovery process, both in terms of the process itself as cost minimization. The objective of this work was to evaluate the development of a mixed reforestation with native and exotic species in a degraded area by soil compaction. The planting was carried out where there was an unpaved airstrip at Itutinga town, MG. The evaluation of tree species was carried out using five plots of 1,250 m² (25 m x 50 m), systematically distributed. The mechanical resistance of the soil to penetration was determined using an impact penetrometer to a depth of 60 cm. To evaluate the influence of soil mechanical resistance to penetration on tree growth, the Pearson r correlation index was calculated. In the inventory, 534 tree individuals with CAP equal to or greater than 5 cm, belonging to 41 species, were measured and identified in the study area. Most of the inventoried individuals come from species used in planting and most of the species with the highest importance values belong to the ecological group of pioneers. The predominance of trees that are attractive to the fauna and native to the region indicate that the forest succession will occur satisfactorily. The soil resistance to penetration negatively influenced the basal area, that is, the greater the soil compaction in this layer, the lower the occupation of the stand.

Root density of Megathyrsus maximus BRS Quênia and Urochloa brizantha BRS Piatã in silvipastorl systems

Mon, 03 Jun 2024 00:00:00 -0300

The objective of this study is to determine the root density of Megathyrsus maximus and Urochloa brizantha forages at a depth of 20 cm alone, in relation to their distances from the tree component in two systems of livestock-forest integration with two entities. For this study, the following livestock-forest integration systems were carried out: a system with 3 years of composting by AEC-043 eucalypts clones spaced in strips of simple lines of 15x2 m and the forage component Megathyrsus maximus cv. Quenia; The other system requires 2 years of growth and AEC-2034 eucalyptus clones with the same forest root and forage component Urochloa brizantha BRS Piatã. Five transects were collected randomly in each of two livestock-forest integration systems and measured 5 distances from the tree component for root collection in the dry period. The roots are separated and dried only for density evaluation. In the area as a livestock-forest integration system with 2 years of life with eucalypts clones AEC-2043 and Urochloa brizantha forage, a higher average production of total density of roots at a distance of 5 meters from the tree component, with value of 11.75 g and less root density at zero distance with 8.63 g. In the 3-year livestock-forest integration system, with AEC-043 eucalyptus clones and Megathyrsus maximus forage component, the highest concentration of root density occurred at distance zero with 10.23 g and lowest root density at distance 5 m with 4.45 g. In both systems, eucalyptus influenced the root system of the forage grass.