Search

Monitoring the spatial variability of soil attributes is an important tool in crop management. Multivariate statistical methods and geostatistics were jointly applied to evaluate the influence of different attributes on spatial variability in the soil. The aim of this research was to apply multivariate principal component analysis to map the spatial variability of the soil in an area subjected to different methods of conservation management and identify the most relevant physical and chemical attributes. Disturbed and undisturbed soil samples were collected and georeferenced at 99 different points in the study area at depths of 0.00-0.10 m and 0.10-0.20 m to measure the physical and chemical attributes of the soil; multivariate principal component analysis (PC) was then applied to the data. Geostatistics was applied to the PCs showing greater explanatory capacity, evaluating spatial dependence, and generating maps of spatial variability. The variance in the soil attributes was explained by the first eight PCs. Soil density, particle density and pH had the greatest influence on the spatial variability of the soil since they showed the highest correlation with the PC with the greatest explanatory power. The PCs that correlated with at least two of the soil attributes showed moderate (PC1 and PC6) and strong (PC2, PC4 and PC5) spatial dependence. The generated maps helped identify the joint influence of the variability of the most relevant attributes, making it possible to characterise regions under different methods of conservation management. [ABSTRACT FROM AUTHOR]

Cacao is the most important agricultural product in the southern region of Bahia state, Brazil, with 70 % of its production occurring under the traditional agroforestry where cacao is mostly shaded by native trees. This traditional system allows to reconcile the production with the maintenance of the portion of original biodiversity. However, increased deforestation and intensified agroforestry management aimed at boosting productivity may impact the diversity of native species and the services they provide. In this context, our aim was to disentangle the role of landscape forest cover and the local vegetation complexity on predation of caterpillars and herbivory of cacao plants located in agroforestry systems. The study was conducted across 18 cacao agroforest sites in southern Bahia located in landscapes with different amounts of forest cover. We assessed predation rate using dummy caterpillars, sampling understory birds and arthropods and collected leaves of cacao trees to analyze damage by herbivory. We also measured shading levels and the abundance of cacao trees in each agroforestry. Predation pressure on dummy caterpillars was positively influenced by the abundance of total predators and the level of landscape forest cover and negatively by the number of cacao trees. Even so, we found no evidence that landscape, local features or the actual invertebrate assemblages (predators or herbivores) influenced the cacao leaf damage. The findings highlight the multifaceted interactions between ecological factors, predation pressure, and leaf damage within cacao agroforestry systems. • Landscape forest cover affects predation of dummy caterpillars in cacao agroforestry systems. • Abundance of cacap trees negatively affects caterpillar predation. • Leaf damage in cacao trees not explained by ecological variables studied. • Dummy caterpillar predation on cocoa agroflowers was not influenced by shade levels. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Geografia: Revista Colombiana de Geografía is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Universidad del Valle de Guatemala is the property of Universidad del Valle de Guatemala and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Universidad del Valle de Guatemala is the property of Universidad del Valle de Guatemala and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Universidad del Valle de Guatemala is the property of Universidad del Valle de Guatemala and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Allometric relationships between Girth at Breast Height (GBH), height, age and carbon content in eucalyptus trees were established using100 trees of age varying from 0.5 to 24 years, height from 1.20 to 21.10m and GBH from 6.10 to 74.92cm. Regression equation with GBH i.e. y = 2.224 x -- 35.80, r² = 0.89 (p<0.01) was found to be the most practical and precise for determining the carbon content in eucalyptus trees. The equation was applied in Eucalyptus-Triticum aestivum (wheat) agroforestry system established at farmer's field in Jabalpur, M.P. (India). Determination of carbon stock potential of eucalyptus trees in wheat-based agroforestry and its relationship with the productivity of the crop revealed that carbon content in eucalyptus trees increased when cultivated with wheat in agroforestry system. Although, this upsurge gradually declined with age of the trees with maximum (32.64%) in 1.5 years to 0.38% in 4.5 years old trees. Simultaneously, economic yield and crop biomass of wheat crop also declined with increase in age of eucalyptus trees. The results suggest that wheat can be cultivated with eucalyptus trees during initial two years of plantation to enhance carbon stock in trees without affecting crop productivity. [ABSTRACT FROM AUTHOR]

Highlights • Regional assessment of open oak woodland tree decline. • Open oak woodland decline was related to high annual temperatures. • Intensive management probably contributed to oak decline. • Alternative practices are urgent to mitigate tree decline in similar agroecosystems. Abstract Evergreen oak woodlands in the Western Mediterranean exploited as agrosilvopastoral systems have often been considered as a sustainability paradigm. Yet, these ecosystems show profound symptoms of degradation with widespread tree decline and increased mortality, making them a paradigmatic example of overexploited ecosystems threatened by global change. Understanding the biotic and abiotic, environmental and management factors involved in the current decline of these open woodlands is key to derive sustainable management options. Our goal was to evaluate the potential role of climate and land-use legacies as drivers of tree decline in Quercus ilex open woodlands at the regional level in western Spain. We analysed tree recruitment and health as proxies to the key processes implied in ecosystem decline. Overall, tree health was poor. Levels of tree decline followed a latitudinal gradient, with cooler stands in the North exhibiting better health (i.e. fewer, less severe decline symptoms) and higher sapling and seedling abundance than warmer stands in the South. Warmer conditions and more intense human management, indirectly expressed by stands with lower canopy cover and larger trees, were directly related to both worse plot health and lower tree regeneration. The widespread tree decline and very low recruitment abundance observed in the open oak woodlands studied may be the consequence of negative synergistic effects of a more limiting climate and land-use legacies from human overexploitation of a fragile ecosystem. These results warn of the negative impacts that land-use practices can exert on similar agrosilvopastoral ecosystems with the added risks of ongoing climatic changes, threatening ecological and economical sustainability. [ABSTRACT FROM AUTHOR]

Copyright of Arquivo Brasileiro de Medicina Veterinaria e Zootecnia is the property of Universidade Federal de Minas Gerais, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Paulownia sp. is spread worldwide, being recognized as a 'precious tree' due to its high economic and ecological value. The products obtained from the leaves, skin, branches and flowers of Paulownia sp. are used in various forms of therapy both internally and externally, in countries such as China or Japan this plant bearing special significance since ancient times. At present, Paulownia sp. bears a particular economic importance, the demand for wood being very high. Its cultivation is highly advantageous in comparison with other crops as it can be used in its entirety, from root to seed. However, few consumers are aware of the real energetic, therapeutic and economic importance of Paulownia sp. This is a high productivity crop and the selling price across European markets is highly attractive. In addition, this tree contributes to the preservation of ecological balance and the environment. The paper is a research paper and presents the results of research conducted worldwide on the demands of Paulownia sp. crops in regard to the pedoclimatic factors, its uses as an energetic plant and the ecologic benefits of its cultivation, i.e. the phytoremediation of heavy metal polluted soils and salt soils, as well as its use in agroforestry systems. The paper contains data regarding the history and situation of Paulownia sp. crops in Romania. [ABSTRACT FROM AUTHOR]

Cocoa Swollen Shoot Virus Disease (CSSVD) is one of the major factors limiting cocoa ( Theobroma cacao L.) productivity in West Africa. The only cure for CSSVD is to cut out visibly infected trees and the official eradication campaign in Ghana has cut out more than 200 million trees since 1946. 80 years of research on preventive control measures have mainly focused on resistance breeding, mild strain cross-protection (inoculation of cocoa seedlings with a mild strain of the virus to protect against the severe strain) and control of mealybug vectors. Meanwhile, diversification measures such as agroforestry (for shading) or barrier (strip) cropping have received less attention. Despite promising results, CSSVD is more prevalent in the field than ever before. The large body of knowledge on preventive control measures for CSSVD is fragmented and many publications are not easily accessible. Furthermore, the literature has never been systematically evaluated and quantitatively assessed. Hence, we consolidated this knowledge with an extensive literature review followed by meta-analysis to identify the pertinent research gaps. Out of 423 publications on CSSVD-related issues, we selected 34 studies, which contained 52 datasets on seven different preventive control measures. Results showed that resistance breeding and mild strain cross-protection may reduce CSSVD infection by 30 percent, while the potential of diversification measures (shading/agroforestry and barrier (strip) cropping) seems to be considerably higher (40 and 85 percent, respectively). However, there is a lack of evidence because of a low number of studies about diversification measures, indicating that our results have to be interpreted with care and calling for more research in this area. Future testing is needed to evaluate the efficacy of barrier (strip) cropping to reduce CSSVD, and address the effect of shade on CSSVD symptom severity. Furthermore, the practical relevance of different preventive control measures for farmers needs to be assessed, and shade should be considered in current breeding programs for CSSVD resistance. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a land comprehensive utilization system, agroforestry system can absorb and fix CO2 effectively to increase carbon storage, and also reduces greenhouse effect convincingly while reaching the aim of harvest. The regulatory role in CO2 makes humans realize that agroforestry systems have significant superiority compared with single cropping systems, therefore, understanding the carbon sinks of different components in an agroforestry system and its influencing factors play an important role in studying global carbon cycle and accurate evaluation of carbon budget. This paper reviewed the concept and classification of agroforestry system, and then the carbon sequestration potentials of different components in agroforestry systems and influencing factors. It was concluded that the carbon sequestration rate of plants from different agroforestry systems in different regions are highly variable, ranging from 0.59 to 11.08 t C∙hm-2∙a-1, and it is mainly influenced by climatic factors and the characteristics of agroforestry systems (species composition, tree density and stand age). The soil C sequestration of any agroforestry system is influenced by the amount and quality of biomass input provided by tree and nontree components of the system and the soil properties such as soil texture and soil structure. Overall the amount of carbon storage in any agroforestry system depends on the structure and function of its each component. The future studies should focus on the carbon sink functions of structurally optimized agroforestry systems, the temporal variation and spatial distribution pattern of carbon storage in agroforestry system and its carbon sequestration mechanism in a long time. [ABSTRACT FROM AUTHOR]