Manual Crowning Versus Cardboard in Forest Restoration: Costs and Effect on Seedling Development

Abstract

Invasive grasses are one of the biggest obstacles to be overcome in restoration plantations. Thus, developing efficient and low-cost techniques to overcome this obstacle is a challenge for science and the ecological restoration practice. The objective of this study was to evaluate the effect of the use of cardboard for the crowning operation on the growth of forest tree species from the Atlantic Forest biome and on the operating costs of this technique in a reforestation implemented in Seropédica, Rio de Janeiro state. The predominant vegetation of the area was of Andropogon bicornis L. An experiment was installed in randomized blocks, with two treatments and 12 replications. The treatments consisted of crowning with cardboard and crowning with hoe. The used cardboard (50 x 50 cm) were pre-treated with a preservative solution with CuSO4. Treatments were applied to 11 forest species from the Atlantic Forest biome: Anadenanthera colubrina var. cebil (Griseb.) Altschul, Citharexylum myrianthum Cham., Enterolobium contortisiliquum (Vell.) Morong, Eugenia brasiliensis Lam, Eugenia uniflora Lam, Handroanthus chrysotrichus (Mart. ex DC.) Mattos, Hymenaea courbaril L., Inga laurina (Sw.) Willd., Plinia cauliflora (Mart.) Kausel, Plathymenia reticulata Benth. e Triplaris americana L. Evaluations were carried out as for height, diameter at collar height (DCH) and survival rate, 6, 12 and 18 months after planting. The costs of each crowning method were also quantified. Overall, the height, DCH and growth rates did not differ between the crowning treatments for the species evaluated. However, the cardboard crowning treatment showed a higher survival rate (80%) of plants, compared with the hoe crowning (73%). The cost of the crowning with cardboard over a 12-month period was 40% lower than that of the crowning with hoe. These results show that the cardboard crowning technique can be a viable and a cost effective alternative to replace the crowning with hoe in reforestation areas with species from the Atlantic Forest biome.

Coroamento com papelão para controle de braquiária na formação de povoamento para restauração florestal

“…The bars refer to the standard deviation. Gonçalves et al (2018) avaliaram o efeito do emprego do papelão na supressão de gramíneas e no crescimento de espécies arbóreas no município de Seropédica, RJ. Os autores constataram que aos 18 meses após plantio, a taxa de sobrevivência foi maior no tratamento com papelão, enquanto que os crescimentos em altura e diâmetro ao nível do solo não foram afetados, quando comparados ao coroamento manual.…”

“…Era esperado que o coroamento com papelão compensasse os custos com coroamento manual, devido ao elevado número de intervenções necessárias, como relatado por Gonçalves et al (2018), que constataram economia de até 50% no custo de manutenção quando o uso de papelão foi comparado ao coroamento com enxada durante os 12 primeiros meses após o plantio. No entanto, em razão da baixa durabilidade do papelão nesse trabalho, o tempo não foi suficiente para abater o custo de aquisição, preparo e transporte das embalagens, sendo o custo do coroamento com papelão cerca de 65% superior ao coroamento manual (Tabela 1).…”

“…Dentre as operações para controle de plantas daninhas que mais necessitam de mão de obra, tem-se a roçada semimecanizada e coroamento manual (Eloy et al, 2014). Em vista da necessidade de buscar alternativas, uma opção seria a utilização de papelão para o coroamento das mudas recém-plantadas em campo (Gonçalves et al, 2018;Silva et al, 2018). Essa técnica tem como objetivo promover o coroamento artificial das mudas, eliminando a necessidade de coroamentos manuais realizados com enxada.…”

Efficiency of Cardboard Crowning on the Suppression of Invasive Alien Grasses

“…In this sense, crowning seedlings with cardboard has been proposed as an efficient and low-cost alternative for controlling weed competition in reforestation areas (Martins et al, 2004;Palhares et al, 2011;Gonçalves et al, 2018;Silva et al, 2018;Benites et al, 2020). Cardboard is expected to inhibit seed germination and also lead to the senescence and death of undesirable existing vegetation, in order to control competition.…”

Grasses Control Strategies in Setting Restoration Stand of the Atlantic Forest

“…Weed control in forest restoration is usually performed by employing mechanical techniques, as mowing and hoeing. However, as underlined by Vasic et al (2009) in areas infested by fast-growing weeds, as the brachiaria grasses, the mechanical method is not so effective, in addition to having high cost attached to labour force (Gonçalves et al, 2018;Santos et al, 2018). Thereby, it is important to pursue controlling alternatives to weed species in forest setting stands aiming forestry restoration.…”