Nsalambi Vakanda Nkongolo

Plant species can significantly influence soil micronutrients. We assessed how soil micronutrients (B, Fe, Cu, Zn, Mn) and aluminum (Al) were affected by soil depth (SD) and plant species (PS) in a secondary forest at Masako Forest Reserve. Soil samples were collected in June 2022 and June 2023 along five PS (Entandrophragma utile, Hevea brasiliensis, Milettia laurentii, Musanga cecropoides, and Triculia africana). Four trees (replications) were selected per plant species. A completely randomized design was used with five PS and three SD (0–10 cm, 10–20, and 20–30 cm) and was replicated four times. To collect soil samples, a pit was dug at each sampling location (near a tree), and three soil samples were taken horizontally in the middle of each layer on one of the four faces of the pit, with a 5 cm height and 5 cm diameter cylinder. Soil samples were air-dried, mixed, and sieved to 2 mm, and a 20 g subsample was sent to Brookside Laboratories (OH, USA) for analyses of soil micronutrients. The results showed that most micronutrients were concentrated in the topsoil (0–10 cm). Plant species such as Treculia africana, Millettia laurentii, and Musanga cecropoides enhanced micronutrients in the soil in which they grew, especially iron (Fe) and zinc (Zn). The effect of the year of sampling on micronutrients was prevalent for many micronutrients, which remained significantly higher in 2022 than in 2023. These findings provide a foundational framework for developing nature-based biofortification strategies. By prioritizing key native plant species, local stakeholders can optimize soil health in the Congo Basin.

Plant species in secondary forests can significantly influence soil nutrients. We assessed how soil micronutrients (B, Fe, Cu, Zn, Mn) and Al were affected by plant species in secondary forests at Masako Forest Reserve. Soil samples were collected in June 2022 and 2023 at three depths: 0–10 cm, 10-20 and 20-30 cm along five plant species. A com-pletely randomized design was used with 3 soil depths (SD) x 5 plant species (PS) replicated 4 times. Soil samples were air-dried, sieved 2 mm and sent to Brookside Laboratories (OH, USA) for analyses. Results showed that in 2022, Mn (p=0.0014) and Al (p=0.0216) were significantly affected by SD. Mn (18.30 mg/kg) concentrations were higher in 0-10 cm while Al (443.80 mg/kg) was concentrated in 20-30 cm depth. Boron, Fe, Mn, Zn and Al were all significantly affected by PS (p< 0.01). The soil under Musanga cercopoides had the highest concentrations of Mn, Cu (in magnitude), Zn and lowest in Al. Boron (0.50 mg/kg) and Fe (215.67 mg/kg) were highest in soils under Tricula Africana. As in 2022, Mn (p=0.0166) was also significantly affected by SD in 2023 with its highest concentration (5.45 mg/kg) in 0-10 cm. As for 2022, the soil under Tricula Africana had significantly higher concentrations of Fe (192.67 mg/kg) and Zinc (27.76 mg/kg). The 0-10 cm layer seems to significantly hold more nutrients as compared to deeper soil layers. Triculia africana seems to play a significant role in micronutrients cycling at Masaka Forest Reserve.

Plant species can significantly influence soil nutrients. We assessed how soil micronutrients (B, Fe, Cu, Zn, Mn) and Aluminum were affected by plant species in agricultural fields at Masako Forest Reserve. Soil samples were collected in June 2022 and 2023 at three depths: 0–10 cm, 10-20 and 20-30 cm in fields grown to Costus lucanusianus, Manihot esculenta, Zea mays, Triumfetta cordifolia, and Xanthosoma sagittifolium. A completely randomized design was used with 3 soil depths (SD) x 5 plant species (PS) replicated 4 times. Soil samples were air-dried, sieved 2 mm and sent to Brookside Laboratories (OH, USA) for analyses. Results showed that in 2022, Fe, Mn, Cu and Zn were significantly affected by soil depth (p< 0.05). Mn, Cu and Zn concentrations were higher in 0-10 cm while Fe dominated in 10-30 cm depth. Only Cu (p=0.0001) was affected by plant species. The soil under Xanthosoma sagittifolium (0.19 mg/kg) and Triumfetta cordifolia (0.47 mg/kg) had significantly the lowest level of Cu. In 2023, however, only Zn was significantly affected by SD (p=0.0004) with its highest level (1.22 mg/kg) in 0-10 cm. PS significantly affected Fe, Mn, Cu, Zn and aluminum (p< 0.05). The soil under Manihot esculenta had the highest concentration of Fe (171.42 mg/kg) while Zn (1.03 mg/kg) was significantly higher in the soil under Zea mays. The 0-10 cm layer significantly held more micronutrients. Plant species such as Manihot esculenta had a noticeable effect on soil micronutrients.

Winter cover crop performance metrics (i.e., vegetative biomass quantity and quality) affect ecosystem services provisions, but they vary widely due to differences in agronomic practices, soil properties, and climate. Cereal rye (Secale cereale) is the most common winter cover crop in the United States due to its winter hardiness, low seed cost, and high biomass production. We compiled data on cereal rye winter cover crop performance metrics, agronomic practices, and soil properties across the eastern half of the United States. The dataset includes a total of 5,695 cereal rye biomass observations across 208 site-years between 2001–2022 and encompasses a wide range of agronomic, soils, and climate conditions. Cereal rye biomass values had a mean of 3,428 kg ha⁻¹, a median of 2,458 kg ha⁻¹, and a standard deviation of 3,163 kg ha⁻¹. The data can be used for empirical analyses, to calibrate, validate, and evaluate process-based models, and to develop decision support tools for management and policy decisions.

Mycorrhizae, a form of plant–fungal symbioses, mediate vegetation impacts on ecosystem functioning. Climatic effects on decomposition and soil quality are suggested to drive mycorrhizal distributions, with arbuscular mycorrhizal plants prevailing in low-latitude/high-soil-quality areas and ectomycorrhizal (EcM) plants in high-latitude/low-soil-quality areas. However, these generalizations, based on coarse-resolution data, obscure finer-scale variations and result in high uncertainties in the predicted distributions of mycorrhizal types and their drivers. Using data from 31 lowland tropical forests, both at a coarse scale (mean-plot-level data) and fine scale (20 × 20 metres from a subset of 16 sites), we demonstrate that the distribution and abundance of EcM-associated trees are independent of soil quality. Resource exchange differences among mycorrhizal partners, stemming from diverse evolutionary origins of mycorrhizal fungi, may decouple soil fertility from the advantage provided by mycorrhizal associations. Additionally, distinct historical biogeographies and diversification patterns have led to differences in forest composition and nutrient-acquisition strategies across three major tropical regions. Notably, Africa and Asia’s lowland tropical forests have abundant EcM trees, whereas they are relatively scarce in lowland neotropical forests. A greater understanding of the functional biology of mycorrhizal symbiosis is required, especially in the lowland tropics, to overcome biases from assuming similarity to temperate and boreal regions.

Background and Objective: Knowledge of the spatial distribution of trees and stands is very important in forest management strategies. This study investigated whether spatial interpolation methods could predict the spatial distribution of tree species and their biomass in a mixed forest of Yangambi Biosphere, Democratic Republic of Congo. Materials and Methods: A 90×90 m grid was installed in a mixed forest, the coordinates of each selected tree were recorded with a GPS and the Diameter at Breast Height (DBH) measured. The 3 biomass was estimated with an allometric equation. Data was transferred to ArcGIS 10.3 software where maps predicting the spatial distribution of tree species and biomass were made using ArcGIS-Geostatistical Analyst Extension. The 7 spatial interpolation methods were tested: Inverse Distance Weighting (IDW), Simple, Ordinary and Universal Kriging (SK, OK and UK), Local Polynomial Interpolation (LPI), Global Polynomial Interpolation (GPI) and Kernel Interpolation (KI). Results:Scorodophloeus zenkeri was the most dominant plant species (31%), followed by Strombosia pustulata (12%) and Microdesmis yafungana (8%). The 3 biomass ranged from 100.32 to 8777.30 kg with a mean value of 2866.70 kg. The coefficient of variation was 72.98% with a standard deviation of 2092.30 kg, suggesting that forest biomass was highly variable. The LPI and GPI methods on the one hand, OK and UK on the other gave similar predictions of tree species. The species spatial distribution verification was nearly consistent with IDW. Conclusion: There is a need to expand the study area later and conduct further investigations to refine the predictions. APA-7 Style Mokea, D.A., Basia, A.A., Nkongolo, N.V. (2023). Predicting the Distribution of Tree Species and Their Biomass in Yangambi Biosphere Using Spatial Interpolation. Trends in Agricultural Sciences, 2(3), 221-231. https://doi.org/10.17311/tas.2023.221.231 ACS Style Mokea, D.A.; Basia, A.A.; Nkongolo, N.V. Predicting the Distribution of Tree Species and Their Biomass in Yangambi Biosphere Using Spatial Interpolation. Trends Agric. Sci 2023, 2, 221-231. https://doi.org/10.17311/tas.2023.221.231 AMA Style Mokea DA, Basia AA, Nkongolo NV. Predicting the Distribution of Tree Species and Their Biomass in Yangambi Biosphere Using Spatial Interpolation. Trends in Agricultural Sciences. 2023; 2(3): 221-231. https://doi.org/10.17311/tas.2023.221.231 Chicago/Turabian Style Mokea, Darceline, Anangi , Albert Angbonga Basia, and Nsalambi Vakanda Nkongolo. 2023. "Predicting the Distribution of Tree Species and Their Biomass in Yangambi Biosphere Using Spatial Interpolation" Trends in Agricultural Sciences 2, no. 3: 221-231. https://doi.org/10.17311/tas.2023.221.231

Background and Objective: Medicinal plants are part of the health system in several countries. However, with the advent of climate change, some of these plants are disappearing. The exploitation of plant species for medicinal use in the villages of Yaboya II and Yasekwe, Turumbu Sector in Isangi territory, Tshopo Province, Democratic Republic of Congo was investigated. Materials and Methods: The survey technique based on a questionnaire coupled with documentary analysis was used. The age of the respondents varied between 20 and 70 years, the majority of respondents were men, i.e., 54.80% against 45.2% of women. The respondents were mostly (51.6%) of primary education level. Results: Twenty-two botanical families were inventoried by local populations for pharmacopeia needs, but the Fabaceae and Euphorbiaceae families were the most exploited at 14.29% each, followed by Rubiaceae with 8.57%, Meliaceae and Apocynaceae with 5.716% each. The bark was the part most used by local populations and cooking was the most used mode of consumption. Conclusion: Given that several diseases are cured, to satisfaction, by these medicinal plants, it would therefore be appropriate to help local populations to better manage this natural resource at a time when climate change is threatening. APA-7 Style Mokea, D.A., Nkongolo, N.V. (2023). Contribution to the Study of the Exploitation of Plant Species for Medicinal Use in the Democratic Republic of Congo. Trends in Agricultural Sciences, 2(2), 93-98. https://doi.org/10.17311/tas.2023.93.98 ACS Style Mokea, D.A.; Nkongolo, N.V. Contribution to the Study of the Exploitation of Plant Species for Medicinal Use in the Democratic Republic of Congo. Trends Agric. Sci 2023, 2, 93-98. https://doi.org/10.17311/tas.2023.93.98 AMA Style Mokea DA, Nkongolo NV. Contribution to the Study of the Exploitation of Plant Species for Medicinal Use in the Democratic Republic of Congo. Trends in Agricultural Sciences. 2023; 2(2): 93-98. https://doi.org/10.17311/tas.2023.93.98 Chicago/Turabian Style Mokea, Darceline, Anangi, and Nsalambi Vakanda Nkongolo. 2023. "Contribution to the Study of the Exploitation of Plant Species for Medicinal Use in the Democratic Republic of Congo" Trends in Agricultural Sciences 2, no. 2: 93-98. https://doi.org/10.17311/tas.2023.93.98