Agroforestry Systems最新文献

Cattle farming is responsible for about 15% of Colombia's greenhouse gas emissions (GHGE). In the department of Cundinamarca, specialized dairy farms located in the high tropics contribute 14% of the national milk production, and 94% of them are small-scale producers. Therefore, mitigation strategies for dairy farms are needed to achieve national GHGE reduction targets. This study aims to quantify the carbon footprint (CF), through a Life cycle Assessment Methodology, of 82 specialized dairy farms at the farm gate in 3 regions of Cundinamarca: Central Savannah, West Savannah and Ubate Valley; and to identify the contribution of Acacia decurrens, Baccharis latifolia, and Sambucus peruviana to milk production increases and GHGE mitigation potential. The comparison of the effect of the tree species on the measured variables was carried out by analysis of variance under a completely random design. GHGE were calculated using the 2019 Refinement to 2006 IPCC guidelines and impact factors from databases. The emission factor for enteric methane from cows was estimated by considering the equation proposed by Niu et al. (Glob Chang Biol 24:3368–3389, 2018). The functional units corresponded to one kg fat and protein-corrected milk (FPCM) and one kg live weight gain in a cradle-to-farm-gate approach. For the 3 regions, enteric fermentation and manure left on pasture were the main on-farm sources of GHGE, and feed manufacturing was the main off-farm source. Milk CFs ranged from 1.5 to 2.2 kg CO₂-eq kg FPCM⁻¹. The inclusion Acacia decurrens, Baccharis latifolia, and Sambucus peruviana in cattle diets reduced the milk CF by 13–26% and increased milk yield by 19–37% in the three regions. Therefore, the inclusion of locally available forages in dairy cattle diets is a potential sustainable GHGE mitigation option that dairy farmers, from the Colombian high tropics, can adopt.

Pathogen dynamics in agroforestry systems result from several mechanisms and interactions whose independent effects are difficult to delineate. In recent decades, it has been shown that shade, as a structural feature in agroforestry systems, influences the spread of pathogens through its physical and biological effects. In Cameroon, citrus trees are mainly grown in cocoa-based agroforestry systems (CBAS), and are threatened by a variety of pathogens. This study examines how shading modifies the microclimate in the local environment of citrus trees in CBAS, and the resulting effect on citrus foot rot disease (PFRD). The study was conducted in the Cameroon agroecological zone with bimodal rainfall, where a network of 20 CBAS plots was established. Primary cartographic and structural data were used to perform static simulations with cumulative shadow overlay in ShadeMotion software. A soil sensor was used to quantify the microclimate by measuring air temperature and relative humidity above and in the soil, as well as soil pH. Relationships between shade rate, microclimatic variables, and PFRD intensity were investigated. Results showed that the effect of temperature on PFRD was independent of shade rate. A dependency relationship between relative humidity above and in the soil and PFRD according to shade rate was found. Indeed, a positive correlation of PFRD with relative humidity was observed for citrus trees located in full sunlight, while a negative correlation was observed for citrus trees located under dense and light shade. Optimization of structural characteristics of CBAS would allow ecological management of PFRD and reduction in the use of chemical pesticides.

The sustainability of silvoarable agroforestry systems largely depends on the choice of suitable crop species and varieties for minimizing competitive interactions in the interaction zone with trees. Up to date crop intraspecific variability has been poorly investigated, and mainly in pot trials under artificial shading. Given this framework, a trial was conducted in field conditions in NE Italy to study the response of 10 common wheat varieties cultivated in the 6-m narrow inter-row of a specialized 4-year old poplar plantation (AF, agroforestry) vs. full sun conditions (C, controls). Here it was demonstrated that large genetic variability exists in wheat, as grain yield reductions under shading ranged between 31 and 75% (average − 57%) depending on variety choice. Better tolerance was highlighted in old varieties (− 44% of yield in AF vs. C), that was associated to greater plasticity in delaying leaf senescence, and increased both leaf area index and SPAD (index of chlorophyll content), while achieving the highest grain protein contents (> 17.3% DW). However, under shading modern wheat varieties still remained the highest yielding, particularly in bread-making varieties (469 g m⁻² on average), thanks to larger improvement of the leaf-to-culm biomass ratio and better harvest index. We conclude that there is large scope for identifying wheat varieties suitable for agroforestry systems, while breeding programs can select for specific morpho-physiological adaptation traits to low irradiance.

Competition or complementarity between associated plants due to belowground interactions has been observed in alley-cropping systems (ACs), but the initialization of these processes remains poorly investigated. Here, we used the core-break and soil coring method to quantify the vertical tree and wheat fine root abundance and biomass down to 120 cm in a 4-year-old temperate AC. Fine roots were measured at 2 m from a reference tree (hornbeam, wild cherry or willow) in tree–wheat AC, pure-forest associated with ryegrass (FC) and wheat sole-crop (CC) plots at the Ramecourt experimental site. The mean wheat fine root abundance (WFRA) was twice as high in the CC plot (874 ± 152 m⁻²) as in the AC plot (437 ± 47 m⁻²). It was significantly higher for wheat associated with hornbeam than for willow, particularly at the 10 cm depth. Tree fine root abundance (TFRA) was linearly correlated with tree fine root biomass (TFRB) for hornbeam (R² = 0.79***), willow (R² = 0.77***) and wild cherry (R² = 0.54***). Using TFRA, the van Noordwijk's equation gave a better prediction of the TFRB for willow and wild cherry than for hornbeam. The mean value of the TFRA was seven times higher in the FC plot (1116 ± 97 m⁻²) than in the AC plot (146 ± 24 m⁻²) for all soil depths and all tree species due to the lack of nutrients from the absence of fertilization. At 4 years old, willow and hornbeam fine roots cohabited with wheat in the upper soil layer, whereas wild cherry had already developed deep fine roots under the crop rooting zone.

Allometric equations were developed for estimating aboveground biomass carbon (AGBC) in five tree species grown in a tree-based intercropping system at the University of Guelph Agroforestry Research Station, Guelph, Ontario, Canada. A total of 66 representative trees from five species: red oak (Quercus rubra) [n = 12], black walnut (Juglans nigra) [n = 16], black locust (Robinia pseudoacacia) [n = 10], white ash (Fraxinus americana) [n = 15], Norway spruce (Picea abies) [n = 13] were selected, harvested and their aboveground biomass and carbon content were quantified. Three commonly used allometric models were used to develop predictive equations. Regression models were developed and parameterized for each tree species and the best are presented based on information criteria (AIC, AICc, and BIC), mean absolute percentage error (MAPE), over/under estimation (MOUE), root mean square error (RMSE), R², and regression coefficients (a, b) of the observed/predicted (OP) linear regression analysis. All equations with diameter at breast height (D) only and D and tree height (H) as the predictor variables fitted the AGBC data well, with R² > 97% and RMSE < 40. However, a power model using D as the only predictor is recommended as the best model for black walnut, black locust, white ash, and Norway spruce. The models presented are the best fitted allometric equations for the indicated species and are recommended for these species, growing on similar soils under the same temperate conditions at densities of < 125 tree per hectare.

Forest landscape restoration through agroforestry has been implemented as a Nature-based Solution to deforestation in the Global South with varied outcomes. The Modified Taungya System (MTS) is one of such programmes introduced in Ghana to address socio-economically-induced degradation of forest reserves. For two decades since its establishment, there has not been any examination of a synthesised findings on the MTS and their implication for the prospects of the programme. Using the PRISMA method to select empirical studies, this article examines the state of reforestation under the MTS by reflecting on the conditions of success and failures of the programme. In doing so, two interrelated arguments are advanced. First, the MTS seems to be successful when farmers are well-educated about the programme and their future benefits in the reserves that they enrich. Second, the MTS has largely failed to achieve its full potentials for forest recovery due to bribery, corruption and nepotism that have bedevilled land demarcation to, and delays in signing benefit sharing agreement with, farmers. There is a need for a thorough sensitisation on the MTS to enhance its transparency. Besides, the MTS needs to be remodified if it would be one of the strategies to contribute to the Bonn Challenge and for a durable climate mitigation.

Agroforestry systems (AFS) are an established and well-documented practice with widely recognized economic, social, and ecosystem benefits. However, literature regarding their woody component analysis for wood products is still incipient. This study aimed to survey articles that report results on the quality of wood produced in agroforestry systems, identify existing knowledge gaps regarding the quality of wood from AFS and, with those results, guide new studies. A search on Scopus and Web of Science was conducted using terms related to agroforestry systems and wood quality. The findings were screened and analyzed, and the main data and wood characteristics of each fitting article were described. This review describes thirteen articles, comprising four countries (Brazil, Costa Rica, France, India and Portugal), and it discusses the properties and potential use of wood from twelve species: Castanea sativa, Cedrela odorata, Eucalyptus grandis × Eucalyptus urophylla, Juglans nigra × regia, Khaya senegalensis, Parapiptadenia rigida, Peltophorum dubium, Populus deltoides × Populus tristris, Quercus robur, Quercus rotundifolia, Schizolobium parahyba and Tectona grandis. Most of the woods had superior or similar characteristics to monoculture ones, except for Tectona grandis. The geographic distribution of those studies is limited, with no studies from Africa and Oceania, and few authors publishing on this subject. Even though AFS is a traditional agricultural practice, few studies address the quality of the wood from this system. This study gathers existing information about the quality of wood produced in AFS, highlighting the knowledge gaps on this theme and indicating improvements for future work.

Despite silvopastoral systems’ environmental and production benefits, their adoption in forest ecosystems has been moderated. Identifying a silvopastoral farm typology combining farm size and management practices can help explore the constraints to their adoption and guide technical support initiatives. We investigated farms adopting silvopastoral systems in the Upper Atlantic Forest of Argentina and whether their management practices are related to the farms structural characteristics. We analysed 60 surveys that covered 3428 ha under silvopastoral management. First, we group the farms according to size and land use using the factor analysis mixed data and group with hierarchical clustering. Second, we performed two correspondence analyses with variables related to management practices in the silvopastoral area to explore the relationship between the practice management adopted and the cluster farm. Our results summarised the variability of farms and management practices in three groups: Specialist silvopastoral farms, Agricultural farms with silvopastoral management and forest plantation, and Livestock farms with silvopastoral management sectors. Specialist silvopastoral farms adopted most of the technical recommendations for this land use. Despite this work contributions, some information gaps still need to be addressed to have an integrated vision of how silvopastoral systems in the Upper Atlantic Forest of Argentina can be adopted in an extended manner.

Most of the community-based forest management (CBFM/PHBM) literature has confirmed the role of social capital (SC) in helping forest-dependent communities access the state-forest areas, which includes its agroforestry lands. Nevertheless, the dynamics of SC to enable the smallholder dairy farmer (SDF) communities to access the agroforestry lands, including gaining, controlling, and maintaining the access, do not receive much attention. This research aims to examine the contribution of SC in promoting SDF communities in Indonesia to access agroforestry lands. Data were gathered through semi-structured interviews with 40 dairy farmers and 25 key informants, focus group discussions, field observations, and document analysis by using qualitative case studies of four SDF communities in West Java province. The findings reveal that SC plays considerable roles in enabling various mechanisms or collective actions, by which the smallholders acquire affordable and long-term access, as well as increasing the communities’ awareness of sustainable forest management. First, SC establishes various affordable options to access agroforestry lands, which include informal access through land-to-labor exchanges between authorities and communities, right-to-use transfer systems, hereditary access schemes, and information sharing among farmers. Furthermore, SC provides low-cost mechanisms for controlling and maintaining access via fenceless agroforestry patch border control and peer-to-peer land supervision. Second, SC contributes to creating mechanisms that lead to long-term access via institution-based systems in maintaining agroforestry land boundaries and function, including the village–forest border system, the land sharing and land sparing use system, the creation of renewable land tenure, and the gradual sanction system. Lastly, the knowledge shared by the forest authority and common knowledge fostered by communities reinforced the communities’ awareness of sustainable forest management.

Faidherbia albida tree is known for its positive influence on most crops due to reverse leafing phenology. This study aimed at investigating the impact of pollarding F. albida on tree growth, wheat physiological performance and soil conditions. The study was conducted from June 2015 to October 2016 in Ejerssa Joro, a semi-arid region of Ethiopia. Leaflet per twig were scored. Sap flow volume and radial cambium growth were measured. Experimental design was employed with 1m² areas under non-pollarded and pollarded trees from three directions and from different distances. Soil moisture, photosynthetically Active Radiation (PAR), air temperature and relative humidity (RH) were measured. Soil physicochemical properties were analysed. Wheat growth and physiology were measured. Sap volume in non-pollarded was 4590 L month⁻¹ in January 2016 when the tree was fully foliated. Despite the spatiotemporal differences in leaflet per twigs between and within the trees, complete reverse leaf phenology was not observed during the study periods. Cambium growth was affected by pollarding F. albida. The PAR level and midday air temperature under non-pollarded were reduced by 77% and 6%, respectively. On the other hand, RH in dry periods and soil moisture in July under non-pollarded were higher by 15% and 42%, respectively. Most of the soil macronutrients found under non-pollarded trees ranged from moderate to high. The SPAD reading, shoot height and number tillers were significantly (p < 0.05) higher under non-pollarded trees compared to under pollarded trees of same distances. Thus, Pollarding F. albida reduced tree growth, wheat productivity, and understory microclimate conditions.