Beschreibung: The forage quality of pasture species is spatially heterogeneous. In this study, we evaluated the dynamics and spatial structure of forage quality and attempted to relate the observed variation to differences in light availability and soil properties. We compared grass forage quality in open grasslands with forest edge environments and established plots in open Japanese grasslands surrounded by secondary forests. We sampled Anthoxanthum odoratum L. and soil from each plot in May and September. These samples were analyzed to determine the crude protein (CP), neutral detergent fiber, and mineral concentrations. We calculated Moran’s I coefficients across discrete lag distance classes to construct autocorrelograms. The CP model showed a non-random pattern in May at a lag distance of 40 m, but a clustered pattern in September at a small scale. The mineral models produced similar clustered spatial patterns. We found no strong correlation between aboveground (plant) and belowground (soil) mineral contents. CP and some mineral element concentrations in the plants collected in September were significantly greater at the forest edge than in open grasslands. The forest edge therefore appears to be a valuable place to provide grazing animals with adequate protein and mineral intake during the later part of the growing season.

Beschreibung: Guazuma ulmifolia was experimentally pruned to determine when pruning should begin during the rainy season in order to extend the production of green tree-forage during the dry season. Three prunings (P-1, P-2, and P-3) were performed (5 weeks apart) during the rainy season (August, September, and October) and four forage harvests (C-a, C-b, C-c, and C-d) (3 weeks apart) took place during the dry season (February, March, and April). Over 2 years, forage biomass production was evaluated as total biomass (g dry matter tree −1 ), biomass of the morphological components (leaves, stems, and dead matter), and nutritional quality (crude protein, fiber, lignin, and digestibility). Date of pruning affected the production of total biomass ( P  = 0.001) with the earliest pruning (P-1) yielding the greatest forage quantity, while stems ( P  = 0.022) and dead matter ( P  = 0.032) varied due to a year by pruning interaction. Total biomass, leaves, stems, and dead matter varied by the interaction between forage harvest and year for all four variables ( P  〈 0.037). In both years, the largest forage harvest occurred in C-b ( P  〈 0.05), leaf production was highest in C-a and C-b ( P  〈 0.001), stem production was greatest in C-b ( P  = 0.013) and dead matter was highest in C-b and C-d ( P  = 0.002). Leaf crude protein ranged between 10 and 19 %, and the interaction of pruning by forage harvest by year was significant ( P  = 0.035). Digestibility, neutral and acid detergent fiber and lignin differed significantly because of the interaction between forage harvest and year ( P  〈 0.005), with February showing the lowest values for fiber and the highest digestibility. The best time to prune G . ulmifolia is in August so that the young trees will produce more total biomass with a higher crude protein content. The most suitable moment for forage harvest is in February when the trees have more leaves with greater digestibility and less fiber.

Beschreibung: Estimates of above-ground biomass are required for better planning, sustainable management and monitoring of changes in carbon stocks in agroforestry systems. The objective of this study was to develop and compare biomass equations for Markhamia lutea, Casuarina equisetifolia, Maesopsis eminii and Grevillea robusta grown in a linear simultaneous agroforestry system in Uganda. These species were established in single rows in the middle of fields in 1995 from four-month old seedlings. A total of 57 trees were sampled for this study, 13 for M. lutea, 12 for C. equisetifolia, 16 for M. eminii and 16 for G. robusta . Biomass values of the various tree components (stem, branches and foliage) as well as the total above-ground biomass were fitted to linear and non-linear allometric models using total height, diameter-at-breast height (DBH), crown width as predictor variables. Although both DBH and height are typically used as independent variables for predicting above-ground biomass, the addition of height in biomass equations did not significantly improve model performance for M. eminii , M. lutea and G. robusta . However, addition of height significantly increased the proportion of variation explained in above-ground biomass for C. equisetifolia , while DBH did not significantly improve the prediction of biomass. The study confirmed the need for developing species-specific biomass equations.

Beschreibung: Shelterbelt systems play an important and long-term role in ecological stability and food security. Today, shelterbelts are threatened by anthropogenic destruction, plant diseases, and insect pests. Determining the continuity of shelterbelts is essential for the management and maintenance of complete and stable shelterbelt systems. In this paper, we acquired SPOT 5 images with a 10 m × 10 m spatial resolution, and, based on a GIS method, we generated belt waveforms using a waveform data collector. We then developed a waveform recognition model for belt continuity based on waveform recognition theory. Finally, we identified a minimum threshold value for the identification of belt gaps, and conducted belt continuity recognition in the study area. The results were compared with data calculated from aerial images with a 0.5 m × 0.5 m spatial resolution. When belt gaps were 〈10 m, recognition was poor, but when belt gaps were between 10 and 20 m, the mean absolute error was 3.8 %, and when belt gaps were 〉20 m, the mean absolute error was 2.7 %. We propose that this method provides a powerful new tool for the investigation and management of shelterbelt systems.

Beschreibung: Granules of calcium carbonate are known to be produced by the calciferous glands of earthworms, and may have a measurable impact on the soil; however, little is known of their dynamics. Earthworms are often found in Tuber melanosporum burns, and this truffle is closely linked to calcium carbonate and soil pH. The present work shows that in weakly calcareous soil burns with high earthworm ( Prosellodrilus sp.) activity, earthworm casts showed a significant increase of 0.2 units of pH and 66 % more total calcium carbonate than soils in the burns, although the casts were produced from these same soils. Analysis of the soil carbonate fractions (active carbonate versus calcium carbonate greater than 50 μm in size) showed that the origin of the increase in the total calcium carbonate content of the Prosellodrilus sp. casts cannot be explained by the levels of original carbonate existing in the soils in the study, although it can be explained by the synthesis of calcite granules by earthworms. These results obtained in the field with Prosellodrilus sp. confirm Canti’s ( 2009 ) experiments in the laboratory using δ 13 C concerning the synthesis of calcite granules by Lumbricus terrestris . Both these results and other works indicate that production of calcite granules by Prosellodrilus sp., L. terrestris , Aporrectodea longa , A. trapezoides and Anisochaetae sp. has the ability to increase soil pH and calcium carbonate; additionally Lambkin et al. ( 2011 ) have found that higher soil pH and carbonates can cause an increase in the production of calcite granules by L. terrestris . All these results, therefore, point to a feedback process, scope of which is a function of the different soil types and earthworm species. In summary, different earthworm species may have a significant and positive impact on soil pH and net recarbonation of T. melanosporum burns, and the importance of both soil properties justifies the development of further experiments aimed at incorporating vermiculture into the truffle cultivations.

Beschreibung: Variation in growth, arsenic and heavy metal uptakes by aboveground tissues (leaves, stems and branches) of 13 hybrid Eucalyptus clones selected for biomass production in a Mediterranean environment ( E. camaldulensis  ×  E. viminalis ; E. camaldulesis  ×  E. grandis ; E. camaldulensis  ×  E. globulus subsp. bicostata ) was investigated on agricultural soils field-contaminated with arsenic (As), cadmium (Cd), chrome (Cr), lead (Pb), copper (Cu) and zinc (Zn) in an ex situ nursery experiment in central Italy. Large variation in growth and contaminant uptake amongst the tested clones was observed. All plants survived and 12 clones grew better than the control ( E. camaldulensis ). All clones accumulated the contaminants to which they were exposed: As, Cu, Pb and Zn concentrations were significantly higher in leaves than in stems and branches, supporting the potential for phytoremediation of these contaminants by Eucalyptus short rotation woody crops (SRWC). Significant positive correlations between the average contents of Cd–Pb, Cd–Cu, Cd–Zn, Pb–Cu, Pb–Zn and Cu–Zn in the aboveground tissues were detected. Clones revealed better phytoextraction performance than that of the control. Four promising clones for biomass production and phytoremediation were identified for prospective use in SRWC on contaminated soils in Mediterranean environments.

Beschreibung: Shade trees play an important role within agroforestry systems by influencing radiation and wind regimes as well as nutrient and hydrological cycling. However, there is a lack of quantitative assessments of their functions. One of the reasons is the rare information on structural characteristics of shade tree species. Therefore, the aim of this study is to provide basic information on the structure of frequently used shade tree species for the implementation of models simulating the ecosystem processes in agroforestry systems. The investigation of the shade trees was conducted at two cacao agroforestry sites on Sulawesi, Indonesia. The measurements of the main structural parameters: diameter at breast height, tree height, trunk height, crown length and crown radius were carried out for the shade tree species Aleurites moluccana , Cocos nucifera and Gliricidia sepium. For data collection, the National Forest Inventory Field Manual Template by FAO ( 2004 ) was applied. Based on this information allometric functions were derived for the correspondent shade tree species. The best significant relationships were obtained for the height-crown length relationship of the dicotyledonous tree species’ A. moluccana and G. sepium with a coefficient of determination r ² = 0.925 and r ² = 0.738, respectively, and the height-crown length relationship of the monocotyledonous palm C. nucifera with r ² = 0.663. The transferability tests ‘analysis of covariance’ and ‘homogeneity of slopes’ have shown that the obtained allometric functions are also applicable to other cacao agroforestry systems of the region.

Beschreibung: The development of farm woodlots as an alternative source of livelihood for smallholder farmers in diverse biophysical and socio-economic conditions is a challenging issue in developing countries, such as Rwanda, where the majority of the population relies on subsistence farming. There is a need to understand why and when farmers decide to grow trees and woodlots on their farms. The objective of this study was to analyse the determinants and the purposes that enhance the propensity to grow woodlots in low, medium and high altitude regions of Rwanda. Necessary information for this study came from a survey of 480 households across these regions. The results showed regional variations in the determinants of woodlot farming, demonstrating the importance of not extrapolating the results between regions. Pooled data across regions indicated that age of the householder, number of salaried household members, farm size, travel distance to fuelwood sources and household location in medium forest cover region had positive significant effects on the propensity to grow farm woodlots. In contrast, household location in low forest cover region, ownership of livestock and monthly frequency of purchasing fuelwood were inversely related to the presence of farm woodlots. Many households planted eucalyptus woodlots for economic reasons, not for environmental purposes. Livestock and crop production were more attractive to rural households than woodlot farming. The findings of the study can be used by policymakers and extension services in order to promote sustainable land use practices by focusing on the challenges of competing land uses, farm size, unemployment, dependence on forests for fuelwood supply and subsistence farming.

Beschreibung: Aiming to support the use of native species from the Atlantic Rainforest in local agroforestry systems, we analysed chemical and biochemical components related to leaf decomposition of Inga subnuda , Senna macranthera , Erythrina verna , Luehea grandiflora , Zeyheria tuberculosa , Aegiphila sellowiana , and Persea americana . These tree species are native (except for P. americana ) and commonly used in agroforestry systems in the Atlantic Rainforest. For the three first species (Fabaceae), we also analysed the remaining dry matter and released nutrients from leaves, using litter bags, and biological nitrogen fixation, using Bidens pilosa and Brachiaria plantaginea as references of non-N 2 -fixing plants. Leaves from I. subnuda , L. grandiflora , and P. americana had a lower decomposition rate than the other species, exhibiting negative correlations with lignin/N and (lignin+polyphenol)/N ratios. The percentages of remaining dry matter after 1 year were 69 % ( I. subnuda ), 26 % ( S. macranthera ) and 16 % ( E. verna ). Higher nutrient release was found in decreasing order from residues of E. verna , S. macranthera , and I. subnuda . The percentages of nitrogen fixation were 22.6 % ( E. verna ), 20.6 % ( I. subnuda ) and 16.6 % ( S. macranthera ). Diversification of tree species in agroforestry systems allows for input of diversified organic material and can contribute to maintaining and improving soil functions resulting in improvements of soil quality.

Beschreibung: The Indo-gangetic plains (IGP) in India occupies 13 % of the total geographical area and produces 50 % of total food grain to feed 40 % population of the country. Dynamic CO2FIX model v3.1 has been used to assess the baseline (2011) carbon and to estimate the carbon sequestration potential (CSP) of agroforestry systems (AFS) for a simulation period of 30 years in three districts viz. Ludhiana (upper IGP in Punjab), Sultanpur (middle IGP in Uttar Pradesh) and Uttar Dinajpur (lower IGP in West Bengal) respectively. The estimated numbers of trees existing in farmer’s field on per hectare basis in these districts were 37.95, 6.14 and 6.20, respectively. The baseline standing biomass in the tree components varied from 2.45 to 2.88 Mg DM ha −1 and the total biomass (tree + crop) from 11.14 to 25.97 Mg DM ha −1 in the three districts. The soil organic carbon in the baseline ranged from 8.13 to 9.12 Mg C ha −1 and is expected to increase from 8.63 to 24.51 Mg C ha −1 . The CSP of existing AFS (for 30 years simulation) has been estimated to the tune of 0.111, 0.126 and 0.551 Mg C ha −1  year −1 for Sultanpur, Dinajpur and Ludhiana districts, respectively. CSP of AFS increases with increasing tree density per hectare. Site specific climatic parameters like monthly temperature, annual precipitation and evapotranspiration also moderates the CSP of AFS. The preliminary estimates of the area under AFS’s were 2.06 % (3,256 ha), 2.08 % (6,440 ha) and 12.69 % (38,860 ha) in Sultanpur, Dinajpur and Ludhiana respectively.