scholarly journals Farm Rejuvenation-Induced Changes in Tree Spatial Pattern and Live Biomass Species of Cocoa Agroforests in Central Cameroon: Insights for Tree Conservation Incentives in Cocoa Landscapes

2021 ◽  
Vol 13 (15) ◽  
pp. 8483
Author(s):  
Frederick N. Numbisi ◽  
Dieudonne Alemagi ◽  
Ann Degrande ◽  
Frieke Van Coillie

Cocoa agroforests sustain ecosystem services (ESs) to varying degrees. These services are otherwise mostly provided by other non-cocoa shade or companion trees. However, the density of shade trees is associated with services and/or disservices that drive farm-specific tree management successions. Considering the growing impacts of climate crisis on farm productivity and the need for adaptation strategies, the ESs are increasingly provisional and contingent on the prevailing vegetation, land tenure, and management successions, amongst others social and ecological factors. To assess the temporal changes in shade management, we surveyed an age gradient of “family farms” in cocoa agroforests created from forest (fCAFS) and savannah (sCAFS) land cover. We evaluated the temporal changes in farm structure, relative tree abundance, and live aboveground biomass of the major canopy strata. We used a spatial point process and linear mixed effect analysis to assess the contributions of associated perennial trees (AsT) on farm rejuvenation patterns. The density of cocoa trees was inconsistent with farm age; this was significantly high on farms in sCAFS (1544 trees ha−1) with spatially random configuration across farm age. On farms in fCAFS, we observed a transition of the cocoa tree configuration in the order regular, random, and clustering from young (with highest density of 1114 trees ha−1) to old farms. On a temporal scale, there is no clear distinction of farm structure and biomass between fCAFS and sCAFS. However, the cycle of tree species and structural composition of the canopy strata are dissimilar; the live biomass allocation for the considered use groups of tree species was different with farm age. The observed dynamics in canopy tree structure and live biomass provide insights into farmers’ temporal allocation of uses and prioritization of different tree species with farm age. We recommend the consideration of such landscape-specific, tree management dynamics in proposing on-farm tree conservation incentives. Our results are also conducive to reliable estimates of the ecosystem services from CAFS in the national implementation of conservation mechanisms such as REDD+.

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1064
Author(s):  
Carola Helletsgruber ◽  
Sten Gillner ◽  
Ágnes Gulyás ◽  
Robert R. Junker ◽  
Eszter Tanács ◽  
...  

Research Highlights: This paper presents a cross-city empirical study on micro-climatic thermal benefits of urban trees, using machine-learning analysis to identify the importance of several in situ measured tree physiognomy traits for cooling. Background and Objectives: Green infrastructure and trees in particular play a key role in mitigating the urban heat island (UHI) effect. A more detailed understanding of the cooling potential of urban trees and specific tree traits is necessary to support tree management decisions for cooling our progressively hot cities. The goal of this study was to identify the influence and importance of various tree traits and site conditions. Materials and Methods: Surface temperature, air temperature at 1.1 m and at tree crown height, as well as wet bulb globe-temperature of shaded and fully sun-exposed reference areas, were used to study the cooling effect of seven different urban tree species. For all 100 individuals, tree height, crown base, trunk circumference, crown volume, crown area, leaf area index (LAI) and leaf area density (LAD) were measured. Measurements were conducted in the cities of Dresden, Salzburg, Szeged, and Vienna as representatives for middle European cities in different climate zones. Results: Beside site conditions, tree species, height, height of crown base, as well as trunk circumference, have a great influence on the cooling effect for city dwellers. The trunk circumference is a very valuable indicator for estimating climate regulating ecosystem services and therefore a highly robust estimator for policy makers and tree management practitioners when planning and managing urban green areas for improving the availability and provision of ecosystem services.


2021 ◽  
Vol 184 ◽  
pp. 106997
Author(s):  
Ann Lévesque ◽  
Charlène Kermagoret ◽  
Thomas G. Poder ◽  
Chloé L'Ecuyer-Sauvageau ◽  
Jie He ◽  
...  
Keyword(s):  

2019 ◽  
Vol 94 (4) ◽  
pp. 1477-1501 ◽  
Author(s):  
Pilar Castro‐Díez ◽  
Ana Sofia Vaz ◽  
Joaquim S. Silva ◽  
Marcela Loo ◽  
Álvaro Alonso ◽  
...  

Land ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 486
Author(s):  
Mai Phuong Nguyen ◽  
Philippe Vaast ◽  
Tim Pagella ◽  
Fergus Sinclair

In recent decades in northwest Vietnam, Arabica coffee has been grown on sloping land in intensive, full sun monocultures that are not sustainable in the long term and have negative environmental impacts. There is an urgent need to reverse this negative trend by promoting good agricultural practices, including agroforestry, to prevent further deforestation and soil erosion on slopes. A survey of 124 farmers from three indigenous groups was conducted in northwest Vietnam to document coffee agroforestry practices and the ecosystem services associated with different tree species used in them. Trees were ranked according to the main ecosystem services and disservices considered to be locally relevant by rural communities. Our results show that tree species richness in agroforestry plots was much higher for coffee compared to non-coffee plots, including those with annual crops and tree plantations. Most farmers were aware of the benefits of trees for soil improvement, shelter (from wind and frost), and the provision of shade and mulch. In contrast, farmers had limited knowledge of the impact of trees on coffee quality and other interactions amongst trees and coffee. Farmers ranked the leguminous tree species Leucaena leucocephala as the best for incorporating in coffee plots because of the services it provides to coffee. Nonetheless, the farmers’ selection of tree species to combine with coffee was highly influenced by economic benefits provided, especially by intercropped fruit trees, which was influenced by market access, determined by the proximity of farms to a main road. The findings from this research will help local extension institutions and farmers select appropriate tree species that suit the local context and that match household needs and constraints, thereby facilitating the transition to a more sustainable and climate-smart coffee production practice.


2021 ◽  
Vol 286 ◽  
pp. 125316
Author(s):  
Shiliang Yang ◽  
Yang Bai ◽  
Juha M. Alatalo ◽  
Huimin Wang ◽  
Bo Jiang ◽  
...  

2019 ◽  
Vol 89 (2) ◽  
pp. e01345 ◽  
Author(s):  
George Van Houtven ◽  
Jennifer Phelan ◽  
Christopher Clark ◽  
Robert D. Sabo ◽  
John Buckley ◽  
...  

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Charles Burdet ◽  
Thu Thuy Nguyen ◽  
Xavier Duval ◽  
Stéphanie Ferreira ◽  
Antoine Andremont ◽  
...  

ABSTRACT Although the global deleterious impact of antibiotics on the intestinal microbiota is well known, temporal changes in microbial diversity during and after an antibiotic treatment are still poorly characterized. We used plasma and fecal samples collected frequently during treatment and up to one month after from 22 healthy volunteers assigned to a 5-day treatment by moxifloxacin (n = 14) or no intervention (n = 8). Moxifloxacin concentrations were measured in both plasma and feces, and bacterial diversity was determined in feces by 16S rRNA gene profiling and quantified using the Shannon index and number of operational taxonomic units (OTUs). Nonlinear mixed effect models were used to relate drug pharmacokinetics and bacterial diversity over time. Moxifloxacin reduced bacterial diversity in a concentration-dependent manner, with a median maximal loss of 27.5% of the Shannon index (minimum [min], 17.5; maximum [max], 27.7) and 47.4% of the number of OTUs (min, 30.4; max, 48.3). As a consequence of both the long fecal half-life of moxifloxacin and the susceptibility of the gut microbiota to moxifloxacin, bacterial diversity indices did not return to their pretreatment levels until days 16 and 21, respectively. Finally, the model characterized the effect of moxifloxacin on bacterial diversity biomarkers and provides a novel framework for analyzing antibiotic effects on the intestinal microbiome.


2020 ◽  
Vol 102 (3) ◽  
pp. 617-632 ◽  
Author(s):  
Paulina Oliva ◽  
B. Kelsey Jack ◽  
Samuel Bell ◽  
Elizabeth Mettetal ◽  
Christopher Severen

Technology adoption often requires multiple stages of investment. As new information emerges, agents may abandon a technology that was profitable in expectation. We use a field experiment to vary the payoffs at two stages of investment in a new technology: a tree species that provides on-farm fertilizer benefits. Farmer decisions identify the information about profitability that arrives between the take-up and follow-through stages. Results show that this form of uncertainty increases take-up but lowers average tree survival, decreasing the cost-effectiveness of take-up subsidies. Thus, uncertainty offers another explanation for why even costly technologies may go unused or be abandoned.


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