Abstract
Wood from reforestation gains market value due to its sustainable and legal origin. Planted forests in Brazil play a crucial role in economic, social and environmental aspects, with Eucalyptus and Pinus dominating the timber sector. However, non-majority species, such as those of the Khaya genus, have attracted great commercial interest due to the quality of their wood, being seen as an alternative to Brazilian mahogany. This study aimed to evaluate the biomass production of Khaya spp. stands and the nutrient uptake impacts in different harvesting scenarios. The research area is in Reserva Natural Vale (RNV) in Sooretama, Espírito Santo state, Brazil. The study was conducted 9.5 years after the planting of the Khaya spp. monoculture at a spacing of five m × five m, and the base fertilization consisted of 150 g of yoorin thermophosphate and 15 g of FTE BR 12 per seedling. The seedlings were of seminal origin, coming from different regions of Brazil and corresponding to three species: Kkaya grandifoliola C.DC (Belém-PA), Khaya ivorensis A. Chev. (Linhares-ES) and Khaya senegalensis A. Juss. (Poranguatu-GO). K. senegalensis exhibited the highest percentage of bark, while K. ivorensis was found to have the highest percentage of leaves. The biomass of the stems and branches did not vary by species. The relative biomass proportions had the following order: branches > stems > bark > leaves. The stocks of Ca and Mg were higher for K. grandifoliola, exceeding those for K. senegalensis (22.1%) for Ca and for K. ivorensis (42.3%) for Mg. The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively. Compared to total biomass harvesting, this represents a reduction in export levels by 91.34% for N, 79.31% for P, 94.66% for K, 94.29% for Ca and 93.28% for Mg. The nutrient uptake assessment demonstrated that more conservative harvest scenarios resulted in lower nutrient losses, indicating the importance of forest management practices that prioritize soil and nutrient conservation. In summary, the findings of this study provide a solid basis for the sustainable management of Khaya spp., highlighting implications for productivity and nutrient dynamics on a small or medium scale.
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Claims 16
Claim · model-written summary
K. senegalensis had the highest bark percentage of biomass.
- Taxon
- K. senegalensis
Khaya senegalensise1 - Outcome
- percentage of barke1
- Direction
- higheste1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e1“K. senegalensis exhibited the highest percentage of bark”
Claim · model-written summary
K. ivorensis had the highest leaf percentage of biomass.
- Taxon
- K. ivorensis
Khaya ivorensise2 - Outcome
- percentage of leavese2
- Direction
- higheste2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e2“K. ivorensis was found to have the highest percentage of leaves”
Claim · model-written summary
Stem and branch biomass did not vary among Khaya species.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e3“The biomass of the stems and branches did not vary by species”
Claim · model-written summary
Relative biomass proportions followed the order branches > stems > bark > leaves.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e4“The relative biomass proportions had the following order: branches > stems > bark > leaves”
Claim · model-written summary
Ca stocks were higher in K. grandifoliola than in K. senegalensis, by 22.1%.
- Taxon
- K. grandifoliola
Khaya grandifoliolae5 - Outcome
- stocks of Cae5
- Direction
- highere5
- Value
- 22.1%e5
- Comparator
- K. senegalensise5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“The stocks of Ca and Mg were higher for K. grandifoliola, exceeding those for K. senegalensis (22.1%) for Ca and for K. ivorensis (42.3%) for Mg”
Claim · model-written summary
Mg stocks were higher in K. grandifoliola than in K. ivorensis, by 42.3%.
- Taxon
- K. grandifoliolaKhaya grandifoliolae5
- Outcome
- stocks of Ca and Mge5
- Direction
- highere5
- Value
- 42.3%e5
- Qualifier
- Mge5
- Comparator
- K. ivorensise5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“The stocks of Ca and Mg were higher for K. grandifoliola, exceeding those for K. senegalensis (22.1%) for Ca and for K. ivorensis (42.3%) for Mg”
Claim · model-written summary
Removing only the stem gave the lowest N uptake (44.17 kg ha-1) among harvest scenarios.
- Treatment
- only the stem was removede6
- Outcome
- nutrient uptakee6
- Direction
- loweste6
- Value
- 44.17e6
- Qualifier
- Ne6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
Claim · model-written summary
Removing only the stem gave the lowest P uptake (10.43 kg ha-1) among harvest scenarios.
- Treatment
- only the stem was removede6
- Outcome
- nutrient uptakee6
- Direction
- loweste6
- Value
- 10.43e6
- Qualifier
- Pe6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
Claim · model-written summary
Removing only the stem gave the lowest K uptake (21.93 kg ha-1) among harvest scenarios.
- Treatment
- only the stem was removede6
- Outcome
- nutrient uptakee6
- Direction
- loweste6
- Value
- 21.93e6
- Qualifier
- Ke6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
Claim · model-written summary
Removing only the stem gave the lowest Ca uptake (52.59 kg ha-1) among harvest scenarios.
- Treatment
- only the stem was removede6
- Outcome
- nutrient uptakee6
- Direction
- loweste6
- Value
- 52.59e6
- Qualifier
- Cae6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
Claim · model-written summary
Removing only the stem gave the lowest Mg uptake (9.97 kg ha-1) among harvest scenarios.
- Treatment
- only the stem was removede6
- Outcome
- nutrient uptakee6
- Direction
- loweste6
- Value
- 9.97e6
- Qualifier
- Mge6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
Claim · model-written summary
Stem-only removal reduced N export by 91.34% relative to total biomass harvesting.
- Treatment
- only the stem was removede6
- Outcome
- export levelse7
- Direction
- reductione7
- Value
- 91.34%e7
- Qualifier
- Ne7
- Comparator
- total biomass harvestinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
e7“Compared to total biomass harvesting, this represents a reduction in export levels by 91.34% for N, 79.31% for P, 94.66% for K, 94.29% for Ca and 93.28% for Mg”
Claim · model-written summary
Stem-only removal reduced P export by 79.31% relative to total biomass harvesting.
- Treatment
- only the stem was removede6
- Outcome
- export levelse7
- Direction
- reductione7
- Value
- 79.31%e7
- Qualifier
- Pe7
- Comparator
- total biomass harvestinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
e7“Compared to total biomass harvesting, this represents a reduction in export levels by 91.34% for N, 79.31% for P, 94.66% for K, 94.29% for Ca and 93.28% for Mg”
Claim · model-written summary
Stem-only removal reduced K export by 94.66% relative to total biomass harvesting.
- Treatment
- only the stem was removede6
- Outcome
- export levelse7
- Direction
- reductione7
- Value
- 94.66%e7
- Qualifier
- Ke7
- Comparator
- total biomass harvestinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
e7“Compared to total biomass harvesting, this represents a reduction in export levels by 91.34% for N, 79.31% for P, 94.66% for K, 94.29% for Ca and 93.28% for Mg”
Claim · model-written summary
Stem-only removal reduced Ca export by 94.29% relative to total biomass harvesting.
- Treatment
- only the stem was removede6
- Outcome
- export levelse7
- Direction
- reductione7
- Value
- 94.29%e7
- Qualifier
- Cae7
- Comparator
- total biomass harvestinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
e7“Compared to total biomass harvesting, this represents a reduction in export levels by 91.34% for N, 79.31% for P, 94.66% for K, 94.29% for Ca and 93.28% for Mg”
Claim · model-written summary
Stem-only removal reduced Mg export by 93.28% relative to total biomass harvesting.
- Treatment
- only the stem was removede6
- Outcome
- export levelse7
- Direction
- reductione7
- Value
- 93.28%e7
- Qualifier
- Mge7
- Comparator
- total biomass harvestinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“biomass production of Khaya spp. stands”
e6“The lowest nutrient uptake occurred in the scenario in which only the stem was removed, with averages of 44.17, 10.43, 21.93, 52.59 and 9.97 kg ha−1 for N, P, K, Ca and Mg, respectively”
e7“Compared to total biomass harvesting, this represents a reduction in export levels by 91.34% for N, 79.31% for P, 94.66% for K, 94.29% for Ca and 93.28% for Mg”