RESUMEN
Vegetation succession can change the function and quality of the soil. Exploring the changes in soil properties during secondary forest restoration is of great significance to promote forest restoration and improve the ecological service function of subtropical ecosystems in South China. In this study, we chose three typical forests in subtropical China as restoration sequences, broadleaf-conifer mixed forest (EF), broad-leaved forest (MF), and old-growth forest (LF), to study the changes in soil physico-chemical and biological properties and the changes of soil comprehensive quality during the secondary succession of subtropical forest. The results showed that the soil physical structure was optimized with the progress of forest succession. The soil bulk density decreased gradually with the progress of forest restoration, which was significantly affected by soil organic carbon (p < 0.01). In LF, the soil moisture increased significantly (p < 0.05), and its value can reach 47.85 ± 1.93%, which is consistent with the change of soil porosity. With the recovery process, soil nutrients gradually accumulated. Except for total phosphorus (TP), there was obvious surface enrichment of soil nutrients. Soil organic carbon (15.43 ± 2.28 g/kg), total nitrogen (1.08 ± 0.12 g/kg), and total phosphorus (0.43 ± 0.03 g/kg) in LF were significantly higher than those in EF (p < 0.05). The soil available nutrients, that is, soil available phosphorus and available potassium decreased significantly in LF (p < 0.05). In LF, more canopy interception weakened the P limitation caused by atmospheric acid deposition, so that the soil C:P (37.68 ± 4.76) and N:P (2.49 ± 0.24) in LF were significantly lower than those in EF (p < 0.05). Affected by TP and moisture, microbial biomass C and microbial biomass N increased significantly in LF, and the mean values were 830.34 ± 30.34 mg/kg and 46.60 ± 2.27 mg/kg, respectively. Further analysis showed that total soil porosity (TSP) and TP (weighted value of 0.61) contributed the most to the final soil quality index (SQI). With the forest restoration, the SQI gradually increased, especially in LF the value of SQI was up to 0.84, which was significantly higher than that in EF and MF (p < 0.05). This result is of great significance to understanding the process of restoration of subtropical forests and improving the management scheme of subtropical secondary forests.
RESUMEN
BACKGROUND: Implementation science (IS) has the potential to improve the implementation and impact of policies, programs, and interventions. Most of the training, guidance, and experience has focused on implementation research, which is only 1 part of the broader field of IS. In 2018, the Society for Implementation Science in Nutrition borrowed concepts from IS in health to develop a broader and more integrated conceptual framework, adapted to the particular case of nutrition and with language and concepts more familiar to the nutrition community: it is called the IS in Nutrition (ISN) framework. OBJECTIVE: The purpose of this research was to generate knowledge concerning challenges and strategies in operationalizing the ISN framework in low- and middle-income country (LMIC) settings. METHODS: The ISN framework was operationalized in partnership with country teams in Kenya and Uganda over a 3-y period as part of the Implementation Science Initiative. An action research methodology (developmental evaluation) was used to provide timely feedback to the country teams, facilitate adaptations and adjustments, and generate the data presented in this article concerning challenges and strategies. RESULTS: Operationalization of the ISN framework proceeded by first articulating a set of guiding principles as touchstones for the country teams and further articulating 6 components of an IS system to facilitate development of work streams. Challenges and strategies in implementing these 6 components were then documented. The knowledge gained through this experience led to the development of an IS system operational model to assist the application of IS in other LMIC settings. CONCLUSIONS: Future investments in IS should prioritize a system- and capacity-building approach in order to realize its full potential and become institutionalized at country level. The operational model can guide others to improve the implementation of IS within a broad range of programs.
RESUMEN
Compared with other forest systems, research interest in the potential for a stronger ecosystem carbon sequestration of evergreen forests throughout subtropical China has greatly increased. The eddy covariance technique is widely employed to determine accurate forest-atmosphere carbon dioxide (CO2) flux, which is subsequently used to determine forest ecosystem carbon exchange characteristics. The Dinghushan Biosphere Reserve, a subtropical monsoon evergreen broad-leaved forest, is a suitable study area due to its warm and humid climate (compared with other regions within the same latitude), consequently playing a role in the carbon cycle in the region. For this study, we hypothesized that the forest land in this region generally acts as a carbon sink, and that its carbon sequestration capacity increases over time despite the influence of climatic factors. Here, we compared net CO2 flux data derived from the eddy covariance technique over an 8-year study window. Additionally, we ascertained the effects of various environmental factors on net CO2 flux, while also using the Michaelis-Menten model and a physiologically based process model to track and report on ecosystem carbon exchange characteristics. We observed seasonal trends in daily ecosystem flux, indicative of sensitivity to climatic factors, such as air temperature, precipitation, and sunlight. The carbon sequestration capacity of the region exhibited seasonal variability, increasing from October to March (-264 g C m-2 year-1, i.e., 48.4%) while weakening from April to September (-150 g C m-2 year-1, i.e., 40.4%) on average. The net ecosystem exchange (NEE) rate varied from -518 to -211 g C m-2 year-1; ecosystem respiration (Re) varied from 1,142 to 899 g C m-2 year-1; and gross primary production (GPP) varied from 1,552 to 1,254 g C m-2 year-1. This study found that even though the Dinghushan Biosphere Reserve generally acts as a carbon sink, its carbon sequestration capacity did not increase significantly throughout the study period. The techniques (models) used in this study are suitable for application in other ecosystems globally, which can aid in their management and conservation. Finally, the Dinghushan Biosphere Reserve is both an exemplary and a model forest system useful in exploring CO2 absorption and sequestration from the atmosphere.
RESUMEN
Cherangani hills, located in Western Kenya, comprises of 12 forest blocks, maintaining great plant diversity. However, little attention to plant diversity studies has been paid to it in the past years. Here, we present a checklist of the vascular plants of this region obtained through intensive field investigations and matching of herbarium specimens. In total, 1296 species, including 17 endemic species are documented, belonging to 130 families and 608 genera. This flora represents 18.50%, 43.83% and 54.17% of the Kenyan species, genera and families, respectively. The habit, habitat and voucher specimens, as well as brief notes on the distribution of each taxon recorded are presented in this checklist. It is the first exhaustive inventory of the terrestrial vascular plants in Cherangani hills which is a significant regional centre for plant diversity.