The leguminous tree species Dipteryx odorata (Aubl.) Willd. and Inga edulis Mart. were grown in the field to reforest a degraded area. To investigate the photosynthetic responses and the initial growth of Amazonian fo...The leguminous tree species Dipteryx odorata (Aubl.) Willd. and Inga edulis Mart. were grown in the field to reforest a degraded area. To investigate the photosynthetic responses and the initial growth of Amazonian forest species under fertilization, the study species were subjected to different treatments: T1 = unfertilized-control, T2 = chemical fertilization, T3 = green fertilization and T4 = green and chemical fertilization. D. odorata showed the highest absolute growth rates in height under treatments T4 (10.2 cm·month-1) and T2 (12.2 cm·month-1). I. edulis exhibited the best performance for this same parameter in T4 (23.0 cm·month-1). The highest photosynthesis values (Pn) for both D. odorata (13.1 μmol·m-2·s-1) and I. edulis (20.6 μmol·m-2·s-1) were found in T4. The two species also showed the highest performance index values (PIABS) under T4 (D. odorata = 2.9 and I. edulis = 5.2). Our results suggest that the combination of green and chemical fertilization was the most effective of the four treatments evaluated for improving the photosynthetic performance and the growth of both species during the initial establishment of the species in a degraded area.展开更多
To determine if reduced tree densities(number of trees per unit area) lead to changes in micro-meteorological and tree physiological characteristics, two areas with different tree densities were assessed. One was an a...To determine if reduced tree densities(number of trees per unit area) lead to changes in micro-meteorological and tree physiological characteristics, two areas with different tree densities were assessed. One was an agrosilvopastoral system(AGP) with low tree density, and the other, a secondary forest(SF) with greater tree numbers, both located in a semiarid region of Brazil. Data were collected simultaneously by two automated weather stations: rainfall, air(T_a) and soil temperatures(T_(s5 cm)), relative humidity(RHair), photosynthetically active radiation(PAR), soil moisture at two depths(M_(s30 cm)and M_(s50 cm)),and wind velocity(Vw). Net photosynthesis in Cordia oncocalyx Allema?o trees was measured with an infrared gas analyzer in February, March, May, July, August and September 2011, which encompasses a rainy period followed by a dry period. Average values of Ta, T_(s5 cm), Vwand PAR were greater and average values of RHairand M_(s50 cm) were lesser in the AGP. Photosynthetic rates were greater in plants growing under the AGP at the onset of the dry season when Vw, PAR and T_(s5 cm)were greater and M_(s50 cm) was lesser. Photosynthetic rates correlated strongly with physical parameters during the dry season, especially under SF. Differences in tree numbers between AGP and SF led to differences in physical environmental parameters;however, the latter had less influence on photosynthetic rates in C. oncocalyx during the rainy season. During the dry season, all physical parameters had an impact on net photosynthesis under SF but not under AGP. This indicates a certain independence of plants in AGP.展开更多
The objective of this study was to evaluate the use of biofertilizers and saline waters on gas exchange and growth of medicinal plant Plectrantus amboinicus. The experiment was conducted in the period February to May ...The objective of this study was to evaluate the use of biofertilizers and saline waters on gas exchange and growth of medicinal plant Plectrantus amboinicus. The experiment was conducted in the period February to May 2013 in a greenhouse. The experimental design was completely randomized in a 2 × 4 factorial arrangement, with two levels of salinity of irrigation water (ECw: 0.7 and 3.1 dS m-1) and four levels of bovine liquid biofertilizer applied to the soil, corresponding to 0%, 10%, 20% and 30% of the soil volume, with five replications. The experiment lasted 60 days, counted from the beginning of the treatments. The stomatal conductance (gs), photosynthesis (A), transpiration (E), intrinsic water use efficiency (WUEi) were performed at the end of the experiment, and the height, number of leaves and stem diameter at the beginning and at the end. Generally plants subjected to salinity of irrigation water of 3.1 dS m-1 had the lowest values of gas exchange. Moreover, the application of biofertilizers and the interaction between this and salinity did not affect any growth variable studied except the stem length in the final phase which was influenced by salinity at 5% probability by F test. The average values of this variable were 57.22 cm and 69.65 cm when applied water ECw: 0.7 to 3.1 dS m-1, respectively. The application of biofertilizers can reduce the effect of salinity on the final plant height of Plectrantus amboinicus, especially when the plants were fertilized with a dose of 20% of biofertilizers.展开更多
基金the National Institute of Amazonian Research(MCTI-INPA)for logistical supportCAPES and CNPq for fellowships and funding for this research
文摘The leguminous tree species Dipteryx odorata (Aubl.) Willd. and Inga edulis Mart. were grown in the field to reforest a degraded area. To investigate the photosynthetic responses and the initial growth of Amazonian forest species under fertilization, the study species were subjected to different treatments: T1 = unfertilized-control, T2 = chemical fertilization, T3 = green fertilization and T4 = green and chemical fertilization. D. odorata showed the highest absolute growth rates in height under treatments T4 (10.2 cm·month-1) and T2 (12.2 cm·month-1). I. edulis exhibited the best performance for this same parameter in T4 (23.0 cm·month-1). The highest photosynthesis values (Pn) for both D. odorata (13.1 μmol·m-2·s-1) and I. edulis (20.6 μmol·m-2·s-1) were found in T4. The two species also showed the highest performance index values (PIABS) under T4 (D. odorata = 2.9 and I. edulis = 5.2). Our results suggest that the combination of green and chemical fertilization was the most effective of the four treatments evaluated for improving the photosynthetic performance and the growth of both species during the initial establishment of the species in a degraded area.
基金the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for their financial support
文摘To determine if reduced tree densities(number of trees per unit area) lead to changes in micro-meteorological and tree physiological characteristics, two areas with different tree densities were assessed. One was an agrosilvopastoral system(AGP) with low tree density, and the other, a secondary forest(SF) with greater tree numbers, both located in a semiarid region of Brazil. Data were collected simultaneously by two automated weather stations: rainfall, air(T_a) and soil temperatures(T_(s5 cm)), relative humidity(RHair), photosynthetically active radiation(PAR), soil moisture at two depths(M_(s30 cm)and M_(s50 cm)),and wind velocity(Vw). Net photosynthesis in Cordia oncocalyx Allema?o trees was measured with an infrared gas analyzer in February, March, May, July, August and September 2011, which encompasses a rainy period followed by a dry period. Average values of Ta, T_(s5 cm), Vwand PAR were greater and average values of RHairand M_(s50 cm) were lesser in the AGP. Photosynthetic rates were greater in plants growing under the AGP at the onset of the dry season when Vw, PAR and T_(s5 cm)were greater and M_(s50 cm) was lesser. Photosynthetic rates correlated strongly with physical parameters during the dry season, especially under SF. Differences in tree numbers between AGP and SF led to differences in physical environmental parameters;however, the latter had less influence on photosynthetic rates in C. oncocalyx during the rainy season. During the dry season, all physical parameters had an impact on net photosynthesis under SF but not under AGP. This indicates a certain independence of plants in AGP.
基金CAPES and INCTSal funding this researchUnilab the granting of a research grant
文摘The objective of this study was to evaluate the use of biofertilizers and saline waters on gas exchange and growth of medicinal plant Plectrantus amboinicus. The experiment was conducted in the period February to May 2013 in a greenhouse. The experimental design was completely randomized in a 2 × 4 factorial arrangement, with two levels of salinity of irrigation water (ECw: 0.7 and 3.1 dS m-1) and four levels of bovine liquid biofertilizer applied to the soil, corresponding to 0%, 10%, 20% and 30% of the soil volume, with five replications. The experiment lasted 60 days, counted from the beginning of the treatments. The stomatal conductance (gs), photosynthesis (A), transpiration (E), intrinsic water use efficiency (WUEi) were performed at the end of the experiment, and the height, number of leaves and stem diameter at the beginning and at the end. Generally plants subjected to salinity of irrigation water of 3.1 dS m-1 had the lowest values of gas exchange. Moreover, the application of biofertilizers and the interaction between this and salinity did not affect any growth variable studied except the stem length in the final phase which was influenced by salinity at 5% probability by F test. The average values of this variable were 57.22 cm and 69.65 cm when applied water ECw: 0.7 to 3.1 dS m-1, respectively. The application of biofertilizers can reduce the effect of salinity on the final plant height of Plectrantus amboinicus, especially when the plants were fertilized with a dose of 20% of biofertilizers.
