Conversion Efficiency of Photosynthetically Active Radiation Into Acacia mearnsii Biomass

Abstract

The objective of this experiment was to determine the conversion efficiency of intercepted photosynthetically active radiation into biomass of Acacia mearnsii De Wild. seedlings. A forest species, plastic tubes (90 cm 3 ), and 11 evaluation periods (up to 180 days after emergence) were used in this study. The leaf area index (LAI), total dry biomass (BIO), global solar radiation (GSR), cumulative intercepted photosynthetically active radiation (PARic), and conversion efficiency of radiation (εb) were determined using a pyranometer (LI200X, LICOR). The value of εb in BIO seedlings of Acacia mearnsii was 7.76 g MJ -1 . LAI was directly related to the efficiency of PARic, and this influenced the development, production potential and accumulation of BIO. The value of GSR flow was 11.81 MJ m -2 day -1 , while the value inside the greenhouse was 6.26 MJ m -2 day -1 .

MORFOLOGIA OVARIANA E DOS OVIDUTOS DE Trachemys scripta elegans (WIED, 1839, TESTUDINES) CRIADAS NO CERRADO BRASILEIRO

“…Guajuvira is indicated for civil construction, due to its characteristics of the wood, as well as for the recovery of degraded areas, since it presents good adaptability to shallow soils and low fertility. In the last decades the production of seedlings has been carried out in a protected environment, this physical environment many changes in the meteorological elements (Trautenmüller et al, 2016) and solar radiation is one of the most modified elements (Behling et al, 2015;Dalmolin et al, 2015;Schwerz et al, 2017), being considered a primordial element so that the seedlings develop of robust form. Plant growth is a ratio of biomass balance accumulated by photosynthesis, crop yield depends on the rates of photosynthesis in any growing environment (ORT & LONG, 2003;PTASINSKI, 2016;TAIZ et al, 2017).…”

“…Thus, the PARint, which is converted into biomass, reveals the conversion efficiency (EB) of the energy use by the species (Monteith, 1977). Most of the time, this conversion has been calculated by the linear function, in which an angulation between the PARint an accumulated biomass determines an EB, as results in the studies developed by Behling et al (2015) and Schwerz et al (2017).…”

“…The leaf area index can also influence εb, this characteristic can be manipulated through the density of plants (Behling et al, 2015). Thus, spacing inquiries have been conducted in order to shorten the period for the crop to intercept the maximum incident solar radiation per unit area and time, resulting in higher productivity (Schwerz et al, 2017).…”

“…Density of plants in the nursery has become an important management practice to optimize space in the environment. In addition, it exerts influences directly on the development and architecture of the plants presenting differentiated patterns in response to the varied spacings (Eloy et al, 2017). In this way, contributing to the distribution of leaf area in the canopy and the way in which solar radiation is intercepted.…”

Temperatura e radiação solar na produção de mudas de cedro australiano

“…Com a crescente demanda por madeira serrada e produtos florestais, cresce a necessidade de elevar a produtividade das espécies arbóreas, associado ao fornecimento de madeira de qualidade (ELOY et al, 2018;MARTINS et al, 2007). Uma das primeiras etapas desse processo está relacionado à produção de mudas de boa qualidade, o que tem grande influência no sucesso da implantação e estabelecimento da cultura (GOMES et al, 2002).…”