Search

In recent decades, urban dispersion has generated a distribution of interconnected urban developments in the territory, resulting in a network city. It is a new shapeless town design in which the growing interurban mobility blurs boundaries and builds diffuse spaces in an urban-rural interface (UR-I).Various authors argue whether there is an urban-rural gradient or if these areas have characteristics of their own, distinct from those of urban space and countryside. Therefore, a literature review is proposed, with the aim of understanding this reality in order to plan new UR-I spaces. Planning stands as the tool capable of responding to this problem. The first reference to UR-I is from 1964; since 1970, studies of this space began to increase, intensifying in 2000. Studies indicate that research on UR-Isis most often associated with the areas of health, sociology, environmental issues, ecology and urbanism, which are relevant areas in the field of territorial planning. The conclusion of this study is that UR-Is are areas with specific characteristics that must be included in urban planning. Therefore, in this study, we have systematically selected information that can help develop future planning tools for UR-Is as a separate and independent system of urban and rural spaces. Finally, this study highlights the need for further multidisciplinaryresearch on UR-Is.

Monitoring of land use, land-use changes, and forestry (LULUCF) plays a crucial role in biodiversity and global environmental challenges. In 2015, the Food and Agriculture Organization of the United Nations (FAO) launched the Global Forest Survey (GFS) integrating medium- (MR) and very-high-resolution (VHR) images through the FAO’s Collect Earth platform. More than 11,150 plots were inventoried in the Temperate FAO ecozone in Europe to monitor LULUCF from 2000 to 2015. As a result, 2.19% (VHR) to 2.77% (MR/VHR) of the study area underwent LULUCF, including a 0.37% (VHR) to 0.43% (MR/VHR) net increase in forest lands. Collect Earth and VHR images have also (i) allowed for shaping a preliminary structure of the land-use network, showing that cropland was the land type that changed most and that cropland and grassland were the more frequent land uses that generated new forest land, (ii) shown that, in 2015, mixed and monospecific forests represented 44.3% and 46.5% of the forest land, respectively, unlike other forest sources, and (iii) shown that 14.9% of the area had been affected by disturbances, particularly wood harvesting (67.47% of the disturbed forests). According to other authors, the area showed a strong correlation between canopy mortality and reported wood removals due to the transition from past clear-cut systems to “close-to-nature” silviculture.

The global distribution of forest trees is essential for monitoring land-use sustainability. For this reason, FAO developed the Global Forest Survey (GFS), a systematic regional level survey with a homogeneous sampling design. Preliminary results revealed an interest in analyzing “Trees Outside Forests” (TOFs). We analyzed more than 11,150 sample GFS plots in temperate FAO-ecozones in Europe through a photo-interpretation approach using FAO’s Collect Earth platform. Our results showed that forest land was the most predominant use of land (41%) in temperate FAO-ecozones in Europe in 2015. Forest IPCC land use followed a moderate upward trend from 2000 to 2015 (0.2%). Trees Outside Forests in temperate FAO-ecozones in Europe accounted for 22% of the inventoried area. Trees Outside Forests represent 30% and 48% of cropland and grassland IPCC land uses, respectively, as well as 75% in settlement uses. Comparing our results with previous studies on the Mediterranean, temperate FAO-ecozone TOFs showed a downward trend in Europe and an upward trend in the Mediterranean area, despite its smaller surface area. The greening of the Common Agricultural Policy may increase the extension of TOFs, although our results may indicate that this effect is not yet evident in the field.

Vegetation indices (VI) describe vegetation structure and functioning but they are affected by illumination conditions (IC). Moreover, the fact that the effect of the IC on VI can be stronger than other biophysical or seasonal processes is under debate. Using Google Earth Engine and the latest Landsat Surface Reflectance level 1 data, we evaluated the temporal patterns of IC and two VI, the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) in a mountainous tropical forest during the years 1984–2017. We evaluated IC and VI at different times, their relationship with the topography and the correlations between them. We show that IC is useful for understanding the patterns of variation between VI and IC at the pixel level using Landsat sensors. Our findings confirmed a strong correlation between EVI and IC and less between NDVI and IC. We found a significant increase in IC, EVI, and NDVI throughout time due to an improvement in the position of all Landsat sensors. Our results reinforce the need to consider IC to interpret VI over long periods using Landsat data in order to increase the precision of monitoring VI in irregular topography.

Truffles contribute both directly and indirectly to important dynamics in the soil web, being involved in a large number of ecological functions that are crucial for terrestrial ecosystems. Despite this, the interrelationships between true truffles, i.e. hypogeous ectomycorrhizal fungi producing valuable fruiting bodies, and other elements of the soil system are largely unknown. In this study, we aimed to shed new light on whether and how much Tuber aestivum affects soil microbial activities (evaluated as enzyme activities), abundance (assayed as soil DNA content) and bacterial genetic diversity along with soil chemical properties. We compared chemical and biological variables inside and outside brules (i.e. areas inhabited by truffles with scarce vegetation cover around host plants) in two seasons, namely spring and summer, using both a linear mixed model and a multivariate two-block partial least squares approach. The areas with truffle presence had higher pH but lower organic carbon and nitrogen content. Similarly, all enzyme activities were lower inside the brule than outside, with the exception of peroxidase. A soil quality index (i.e. AI3) based on three enzyme activities (β-glucosidase, acid phosphomonoesterase and urease) indicated a reduction in soil quality inside the brule. Overall, soil DNA content responded to an interaction of truffle presence/absence and season, while bacterial genetic diversity indexes were higher in spring. Despite the observational nature of this study, results point out that T. aestivum can be considered a key species in the soil where it is present as it was associated with changes in chemistry as well as microbial activity that were generally more conspicuous than mere seasonal effects, although the causative nature of these associations still needs to be confirmed.

Improving trees location under LiDAR-derived digital canopy height models (DCMs) is of great interest as discrepancies between both dataset influence the accuracy of the estimations of forest attributes. A method is proposed for the co-registration of LiDAR-derived DCMs with local field positional measurements under a dense tree canopy. This approach consists of two main stages: (1) the assessment of the match between the LiDAR-derived digital terrain model and topographic surveying measurements when shifting the coordinates around a measured position; and (2) a comparison between the field height of selected trees and the LiDAR-derived DCM. Satisfactory results were obtained from geo-referencing field data and LiDAR models for characterizing the forest structure in heterogeneous Pinus sylvestris stands. Closure error of topographic surveying was 17.7 cm, and GPS accuracy to 95 % probability was below 10 cm, thus considerably lower than the resolution of the LiDAR models (1 m-pixel). The best co-location for field trees and LiDAR models provided a coefficient of determination of 0.56 between field-measured tree heights and LiDAR-derived DCM values.

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 δ13C 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.

Agriculture and forestry traditionally focus on improving plant growth traits based on an anthropocentric point of view. This paradigm has led to global problems associated to soil overexploitation such as soil losses, reductions of the C stock in soils, and the generalized use of fertilizers, which particularly increases the costs of production and pollution treatment. This view may also have limited our understanding of mutualistic symbioses of plants and microorganisms assuming that the main role of non-photosynthetic symbionts is to mobilize the nutrients that are necessary for plant growth and development, and being plants the dominant agents of the symbiotic relationship. In response to these issues, this chapter offers an alternative approach taking advantage of the “rhizo-centric” point of view, where non-photosynthetic partners are the main protagonists in play; and secondly, it builds a multidisciplinary body of knowledge that could be called “rhizoculture”, which includes techniques focussing on the intensification of the development and activity of roots, mycorrhizae, and other symbiotic and free living rhizosphere organisms. In short, rhizoculture may lead to decrease plant production dependence on fertilization and provides other benefits to agriculture, forestry, and the environment. Within this conceptual framework, the first objective of this book chapter is to explore whether there is a “paradox of calcium salts” (i.e., Ca2+ and its salts are simultaneously nutrients, promoters, and stressors for the host plants) that would explain a dominance of mycorrhizal fungi over plants based on inducing a Ca(pH)–mediated chlorosis to the host plants. If this paradigm shifting hypothesis were finally fully verified, it would provide conceptual bases to reconsider our current technologies in agriculture and forestry by introducing the “rhizocultural” approach, based on the management of roots (introducing alternative cultural practices), Ca2+ salts (using liming and other techniques), rock-eating mycorrhizae, organic matter, and the soil microbiome (increasing the presence of symbiotic microorganisms against saprophytes), N and P contents (by aquaculture and smart recycling of organic waste), and the physical properties of the soil (by the activity of soil symbiotic microorganisms and soil fauna, such as ants, termites and earthworms). The development of such new technological approaches in rhizoculture would significantly decrease the high cost and associated pollution of the application of fertilizers and phytochemicals; as well as it would increase soil C stocks, improve the resilience of agricultural and forest systems to environmental disturbances, such as climate change, and enhance food production and security.

Dryland biomes cover two-fifths of Earth´s land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high temporal resolution, which are available through the Google Earth platform. We show that in 2015, 1327 million hectares of drylands had more than 10% tree-cover, and 1079 million hectares comprised forest. Our estimate is 40 to 47% higher than previous estimates, corresponding to 467 million hectares of forest that have never been reported before. This increases current estimates of global forest cover by at least 9%. Fil: Bastin, Jean François. Université Libre de Bruxelles; Bélgica. Food and Agriculture of the United Nations; Italia Fil: Berrahmouni, Nora. Food and Agriculture of the United Nations; Italia Fil: Grainger, Alan. University of Leeds; Reino Unido Fil: Maniatis, Danae. United Nations Development Programme; Estados Unidos. School of Geography and the Environment; Reino Unido Fil: Mollicone, Danilo. Food and Agriculture of the United Nations; Italia Fil: Patriarca, Chiara. Food and Agriculture of the United Nations; Italia Fil: Picard, Nicolas. Food and Agriculture of the United Nations; Italia Fil: Sparrow, Ben. University of Adelaide; Australia Fil: Abraham, Elena Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina Fil: Aloui, Kamel. Ministry of Agriculture; Túnez Fil: Atesoglu, Ayhan. Bartin University. Faculty of Forestry. Department of Forest Enginnering; Turquía Fil: Attore, Fabio. Sapienza University of Rome; Italia Fil: Bassüllü, Çağlar. Food and Agriculture of the United Nations; Italia Fil: Bey, Adia. Food and Agriculture of the United Nations; Italia Fil: Garzuglia, Monica. Food and Agriculture of the United Nations; Italia Fil: García-Montero, Luis G.. Universidad Politécnica de Madrid; España Fil: Groot, Nikée. University of Leeds; Reino Unido Fil: Guerin, Greg. University of Adelaide; Australia Fil: Laestadius, Lars. Swedish University of Agricultural Sciences. Department of Forest Ecology and Management, ; Suecia Fil: Lowe, Andrew J.. University of Adelaide; Australia Fil: Mamane, Bako. Centre Régional AGRHYMET; Nigeria Fil: Marchi, Giulio. Food and Agriculture of the United Nations; Italia Fil: Patterson, Paul. Department of Agriculture. Forest Service. Interior West-Forest Inventory and Analysis, ; Estados Unidos Fil: Rezende, Marcelo. Food and Agriculture of the United Nations; Italia Fil: Ricci, Stefano. Food and Agriculture of the United Nations; Italia Fil: Salcedo, Ignacio. Instituto Nacional di Semiarido; Brasil Fil: Sanchez-Paus Diaz, Alfonso. Food and Agriculture of the United Nations; Italia Fil: Stolle, Fred. World Resources Institute; Estados Unidos Fil: Surappaeva, Venera. Department of Forest and Hunting Inventory of Kyrgyztan; Kirguistán Fil: Castro, Rene. Food and Agriculture of the United Nations; Italia

There are numerous aspects related to Tuber species, which have not been explored to date. Tuber aestivum Vitt. is an ectomycorrhizal fungus, that produces an area (called brule) around the host plant trunk, where the germination of other plants is inhibited. What happens inside this particular environment is still not sufficiently understood, especially in terms of soil fauna. A previous work showed that there were higher microarthropod abundances outside during the period of maximum activity of the mycelium. The genus Folsomia (Isotomidae Family; Order Collembola) showed higher abundance inside. The aim of this paper is to investigate the effects of brule, on soil parameters and soil fauna, during the annual biological cycle of T. aestivum. This study was carried out in nine spontaneous brules situated in Northern Italy (Emilia Romagna Region – Piacenza Province). Soil cores were collected in order to perform soil chemical and biological analysis. Moisture content, pH, organic matter content, total organic carbon were analyzed. Biodiversity and soil quality indices were applied. We found higher pH, lower carbon and organic matter content within the brule. Soil fauna community also showed some differences, seasonal and inside vs outside the brule. Some groups seem to be negatively affected by Tuber while Folsomia genus recorded almost always higher values inside. These results suggest that some organisms, such as some Collembola, might find a favorable environment inside the brule, while others - a negative one. However, these results should be compared by other analysis either on other Tuber species and on other soil organisms, such as nematodes and earthworms.

Most Strategic Environmental Assessment (SEA) research has been concerned with SEA as a procedure, and there have been relatively few developments and tests of analytical methodologies. The first stage of the SEA is the ‘screening’, which is the process whereby a decision is taken on whether or not SEA is required for a particular programme or plan. The effectiveness of screening and SEA procedures will depend on how well the assessment fits into the planning from the early stages of the decision-making process. However, it is difficult to prepare the environmental screening for an infrastructure plan involving a whole country. To be useful, such methodologies must be fast and simple. We have developed two screening tools which would make it possible to estimate promptly the overall impact an infrastructure plan might have on biodiversity and global warming for a whole country, in order to generate planning alternatives, and to determine whether or not SEA is required for a particular infrastructure plan.

The Natural Resources Forum – A United Nations Sustainable Development Journal is running a special series over the 2009–2011 period on themes to be considered by the United Nations Commission on Sustainable Development in its 18th and 19th sessions: chemicals, mining, sustainable consumption and production, transport and waste management. In this issue, experts address the question: “Should sustainable consumption and production be a policy priority for developing countries and if so, what areas should they focus on?

Truffles are abundant in some regions of China. Nevertheless, it was not until the 1980s that Tuber species were discovered by Chinese mycologists. In recent years, international truffle markets have shown an increasing interest in the import of Chinese Tuber. These truffles serve as a complement to European truffles due to their lower prices and their greater availability in a deficit market. However, Chinese truffles have been the subject of fraudulent commercial practices, and these could have a negative effect on truffle culture. These concerns have been behind numerous recent studies designed to obtain detailed information about Chinese Tuber species. Unfortunately, many of these studies are not published in English, and are dispersed throughout the specific local or national bibliography and proceedings of specialized truffle conferences. In view of the need to expand current knowledge of Chinese Tuber species, we present a comprehensive summary of the taxonomy, ecology, mycorrhizae, genetics, biochemistry, and cultivation of Chinese Tuber species. We also provide a synthetic taxonomy and morphological characterization of 16 Chinese Tuber species in order to assist in their verification and monitoring.

Several statistical studies have indicated that a high concentration of active carbonate in the soil favours Tuber melanosporum fruit body production. The amount of active carbonate is significantly higher and the total carbonate is significantly lower inside than outside the T. melanosporum brules. These statistical patterns and other works show that T. melanosporum mycelia may acidify their immediate soil environment and solubilise carbonated fractions. Subsequently, the particular environmental conditions of brule soils may favour a secondary carbonate precipitation with a net increase in active carbonate which would in turn favour T. melanosporum mycelia. The greater brule size and fruiting are simultaneously both related to how well the fungus is growing, suggesting that the model which best explains the cause–effect of all these observations is a feedback process. Other statistical studies suggest that active carbonate favours increased fruiting of T. melanosporum as compared with Tuber aestivum , Tuber mesentericum and Tuber rufum , which has led to the use of calcareous amendments in truffle culture. We have studied the carbonated fractions of 46 soil samples from T. melanosporum plantations contaminated and uncontaminated with Tuber brumale (a serious problem in truffle culture), and it appears that the use of calcareous amendments does not serve to eradicate T. brumale from these plantations. However, we have observed the positive effect of calcareous amendments on the production of fruit bodies of both species. The similar response by T. melanosporum and T. brumale to soil active carbonate may be related to the close phylogenetic relationships between both species. Based on these findings, we propose a new soil nutrition hypothesis as a guide for research procedures in truffle soil ecology. Soils which are high in active carbonate lead to host plant chlorosis, which is a symptom of an underlying nutrient deficiency. This nutrient deficiency could lead to greater colonisation of T. melanosporum ectomycorrhizas and favour the growth of mycelia, fruit body production and brule development, which in turn encourages the formation of new amounts of active carbonate on the basis of the proposed feedback model.

Calcareous amendments are being used in Tuber melanosporum truffle plantations in attempts to eradicate Tuber brumale. However, there are no studies available which provide soil analysis and statistical data on this topic. We studied 77 soil samples to compare the values for carbonates, pH and total organic carbon in T. brumale truffières with the values for T. melanosporum truffières on contaminated farms and in natural areas. Statistical analyses indicate that the concentrations of active carbonate and total carbonate in the soil are significantly higher in T. brumale truffières than in T. melanosporum truffières, but that there are no significant differences in pH and total organic carbon. We conclude that liming would not suppress T. brumale ectomycorrhizas in contaminated T. melanosporum farms, and calcareous amendments do not therefore seem be a means of eradicating T. brumale in these farms.

The natural harvesting and cultivation of Tuber melanosporum (black truffle of Perigord) has spread throughout many countries in recent decades. Other black truffles such as T. aestivum, T. brumale, and T. mesentericum cause damage to T. melanosporum exploitation. These truffle species have been found to be very much present in the mycorrhizal contamination of natural T. melanosporum burns. Nevertheless, different studies have been unable to determine whether the aggressiveness of T. melanosporum and its resistance to this contamination pressure are qualities of the environment or of the soil. Moreover, the biological and physical-chemical conditions causing T. melanosporum burns have yet to be clarified. The aim of this study is therefore to establish the relationship between the carpophore presence of Tuber species (T. melanosporum as compared with T. aestivum and T. mesentericum) and the concentration of soil variables. Principal component analysis (PCA) and analyses of variance (ANOVAs) show ...

It is generally accepted that Sphaerosporella brunnea is a significant ectomycorrhizal contaminant in nurseries producing plants mycorrhized with various species of Tuber, and subsequently in truffieres after outplanting. At the University of Alcala, Spain, 397 small plants of Quercus ilex which were mycorrhized with Tuber melanosporum were inadvertently contaminated with S. brunnea, and this contamination was then monitored for 2 years. Sixty percent of the plants were contaminated and had S. brunnea ascomata on the surface of the container on one or several occasions. However, a Spearman test provided no evidence that S. brunnea mycorrhizas affected T. melanosporum mycorrhization whereas other contaminating ectomycorrhizal fungi significantly did. Therefore, it appears that S. brunnea is not detrimental to plants which are well mycorrhized with T. melanosporum.

In this paper, we present a two-stage approach for characterizing the structure of Pinus sylvestris L. stands in forests of central Spain. The first stage was to delimit forest stands using eCognition and a digital canopy height model (DCHM) derived from lidar data. The polygons were then clustered (k-means algorithm) into forest structure types based on the DCHM data within forest stands. Hypsographs of each polygon and field data validated the separability of structure types. In the study area, 112 polygons of Pinus sylvestris were segmented and classified into five forest structure types, ranging from high dense forest canopy (850 trees ha−1 and Loreýs height of 17.4 m) to scarce tree coverage (60 tree ha−1 and Loreýs height of 9.7 m). Our results indicate that the best variables for the definition and characterization of forest structure in these forests are the median and standard deviation (S.D.), both derived from lidar data. In these forest types, lidar median height and standard deviation (S.D.) varied from 15.8 m (S.D. of 5.6 m) to 2.6 m (S.D. of 4.5 m). The present approach could have an operational application in the inventory procedure and forest management plans.

Screening methodologies for Strategic Environmental Assessment have been developed for the rapid evaluation of the environmental impact of land use change and infrastructure development plans. To be useful, screening methodologies must be fast, simple and unambiguous. Environmental screening should also be done as early as possible to facilitate integration of the screening into the plan itself. It is difficult in practice to conduct environmental screening for plans covering large geographic areas. Our objective was to develop an environmental screening tool for evaluating very large infrastructure plans. Our approach makes use of Geographic Information System (GIS) tools to develop map-based outputs that can be efficiently incorporated back into the planning processes. We analyzed a region of 500 000 km2, using 15 cartographic layers as a basis for the screening assessment. The final screening tool was easy to use and produced plan evaluations that could easily be understood by all those involved in the planning processes.

There are very few studies on Tuber melanosporum associated with Cistus populations. In central Spain, we confirm that C. laurifolius shows carpophore production of Tuber melanosporum . This study demonstrates a correlation between T. melanosporum production and the size of the 41 burns, with burn size explaining 26 % of the variability in carpophore production. However, statistical analysis of the results indicates that average production of 21 burns with Cistus laurifolius is 73 % lower than the production of 20 burns associated with Quercus/Corylus without Cistus laurifolius in this zone, respectively. C. laurifolius develops small burns, which has an impact on their carpophore production, and their soils have 92 % less active carbonate than the burns associated with Quercus/Corylus in this zone, respectively. The low levels of active carbonate allow Cistus laurifolius to grow, but impair Tuber melanosporum production. We thus provide a mechanism, based on the inability of Cistus laurifolius to grow in highly carbonated soils, which contradicts the well-known fact that C. laurifolius might act as a transmitter of Tuber melanosporum mycorrhizae. These results indicate that this rockrose can not be considered a useful species for truffle culture. We thus recommend that particular attention should be given to the concentration of active carbonate present in the soil in future studies on the relationship between Cistus species and truffles.

Most studies on Tuber melanosporum fail to supply statistical data on carpophore production and other quantitative data associated with truffle ecology, such as the development of its burns (truffle production sites). During 7 years, we studied 208 burns associated with Quercus ilex subsp. ballota , Q. faginea , Corylus avellana and Tilia platyphyllos in the centre of the Iberian Peninsula. The results showed that burn size is a very significant factor as it accounts for 38% of the variance in carpophore production. However, no significant difference in the size of burns was observed between five types of wood, although significant variability in carpophore production existed between these wood types. Furthermore, statistical analysis shows that a high concentration of active carbonate in the soil accounts for up to 51% of the variance in T. melanosporum burn size. The ecological conditions of burns cause elevated concentrations of active carbonate and exchangeable Ca 2+ , and T. melanosporum activity and burn size are simultaneously favoured by a high concentration of both factors, which suggests a feedback process. These results may indicate a possible application for the use of calcareous amendments in natural burns and truffle cultivation. Moreover, we also determined the considerable truffle-producing ability and mycorrhizing capacity of Quercus faginea . Although Q. faginea is a very little-known species in truffle culture, the results provide support for its implementation.

In Mediterranean pine forests, truffles and mushrooms generate greater profits than any other woodland products. However, there are no studies on Tuber melanosporum Vittad. associated with pines. For this reason, we have carried out a study of this truffle in mountain woods with Pinus sylvestris L. and P. nigra Arnold subsp. salzmannii (Dunal) Franco, in central Spain. Two hundred and eight Tuber melanosporum burns were monitored for 7 years in five different habitats within the same geographical area. An ANOVA test confirmed significant differences in carpophore production. In higher producing habitats, pines were less abundant. We also confirmed that in 433 burns, T. melanosporum was always unequivocally associated with the root base of Quercus or Corylus trees. Similarly, 14 truffle collectors confirmed that they had never found a single burn with carpophore production associated exclusively with pines. Nevertheless, soil analyses indicated that the soil of these pine woods was very favourable to Tuber melanosporum. We therefore conclude that at present Pinus nigrasalzmannii and P. sylvestris are of little interest to Tuber melanosporum culture, as they hinder carpophore production. However, this study has also confirmed that Pinus nigra salzmannii and P. sylvestris mycorrhize easily with Tuber melanosporum, both in the laboratory and in natural environments. On this basis, we propose that pines may act as transmitters of T. melanosporum, although they do not induce fruiting. As a result, the commercial cultivation of Pinus nigrasalzmannii and P. sylvestris seedlings mycorrhized with Tuber melanosporum is not recommended in truffle culture at the present time.

The Perigord black truffle (Tuber melanosporum Vittad.) can mycorrhize with rockroses (Cistus L.) in Mediterranean forests. These shrubs may be of interest for truffle cultivation as they produce early carpophores, collaborate in tree mycorrhization and in the survival of Tuber melanosporum mycelium. However, there are very few quantitative studies on truffle production associated with Cistus. For this reason, we have carried out a study on the natural production of Tuber melanosporum associated with Cistus laurifolius L. in central Spain. An Anova test confirmed the existence of significant differences in carpophore production in four habitats, with and without the presence of C. laurifolius. Twenty-one burns associated with C. laurifolius showed less significant production than the rest. We also confirmed that in 122 burns, Tuber melanosporum was always unequivocally associated with the root base of Quercus L. or Corylus L. trees. Similarly, five truffle-collectors confirmed that they had never found a single burn with carpophore production associated exclusively with rockroses. It has also been statistically verified that many Cistus die in Tuber melanosporum burns, whereas in old burns with minimum carpophore production, a new colonization of young Cistus has been observed. This study also confirms that C. laurifolius mycorrhizes easily with Tuber melanosporum. We propose that Cistus laurifolius may act as transmitters of Tuber melanosporum, although they do not induce fruiting. Consequently, the commercial cultivation of Cistus laurifolius mycorrhized with Tuber melanosporum for production is not recommended in truffle culture. The results reported substantiate the negative observations in cultivations of T. melanosporum with other Cistus species.

Spain is one of the main truffle‐producing countries in the world, and truffle (Tuber spp.) cultivation in this country is currently undergoing a considerable surge. This work describes the Spanish research history and we list the Spanish references. Until 1993 the Spanish bibliography on truffles was very limited (28 references). However in the last 12 years, Spanish research has produced 200 references on truffles, developed in 13 centres (6 doctoral theses, 67 papers in international scientific congresses, 49 papers in Spanish scientific congresses, 7 documents on websites, 51 published Spanish papers, 12 published articles, and 8 papers submitted to international journals listed in the Journal Citation Report). Moreover, a comparative analysis of truffle research production in Spain, France, and Italy has shown how truffle research in Spain is now on a par with that of France, although it is still lower than Italian truffle research.

In the present study, the active carbonate soil concentration explained 43% of the variance in Tuber melanosporum production. This carbonate is also associated with other soil variables, such as pH, exchangeable Ca2+ content, and stoniness abundance, all of which affect the successful productivity of T. melanosporum carpophores. Moreover, active carbonate and exchangeable Ca2+ participate in the maintenance of the soil's structure and in fungus nutrition. Statistical analysis shows that active carbonate accounted for 42% of the variance in exchangeable Ca2+ concentration, and the exchangeable Ca2+ abundance explained 20% of the variance in carpophore production. In addition, a significant correlation was found between carbonate concentration and surface stoniness. Finally, abundance of surface stoniness explained 24% of the variance in T. melanosporum carpophore production. We suggest that studies should be conducted on the effects of amendments in truffle culture.

There is currently little information available on calcium-soil-ectomycorrhizal (ECM) interactions. However, for decades calcareous amendments have been made in forest soils subject to acid rain in Europe without any clear knowledge of their impact on ECMs and the roots of their host plants. We have therefore performed a review to assess the impact of Ca associated tocalcareous amendments in the soil-ECM-host plant system, which has highlighted: (1) the influence of Ca and its salts (carbonates and oxalates) of biological origin in ECM fungal communities; (2) the impact of Ca on the growth patterns of the host tree roots; (3) the importance for the plants of the rock-eating processes associated to ECMs; and (4) the impact on ECMs of the soil Ca cycle (associated to the litterfall). A greater knowledge of the cause-effect relations between Ca and the soil-ECM-plant system in Mediterranean and temperate forests could have positive repercussions on reforestation projects, actions associated to soil management, the commercial production of ECMs, and the economy of different rural zones in these forest areas.

Aim of study: Tuber aestivum is the most widespread edible truffle, with increasing commercial interest. This species can produce carpophores with conifer hosts, in contrast with the inability of Pinus spp. to induce fruiting in other truffle species such as Tuber melanosporum. Therefore the objective is to compare the characteristics and carpophore production of T. aestivum brûlés associated with Pinus spp. versus Quercus spp.Area of study: We studied the natural habitats of T. aestivum in the Alto Tajo Nature Reserve in central Spain.Material and methods: During 5 years, we monitored the production of carpophores and brûlé size of 145 T. aestivum brûlés associated with Pinus nigra subsp. salzmanni and P. sylvestris and Quercus ilex subsp. ballota and Q. faginea hosts. Statistical treatment was performed using the Statistica Program v. 6.Main Results: The size of brûlés associated with Pinus was significantly smaller than that of brûlés associated with Quercus. However, carpophore production per brûlé, and especially for brûlés of similar size, was greater when the host plant was a pine. After accounting for brûlé size, the production of brûlés associated with Pinus spp. was 2.23 (95% CI, between 1.35 and 3.69) and 1.61 (95% CI, between 1.02 and 2.54) times greater than the production of brûlés associated with Quercus faginea and Q. ilex subsp. ballota, respectively.Research highlights: The considerable ability of Pinus nigra subsp. salzmanni and P. sylvestris to form effective brûlés and to produce carpophores of Tuber aestivum in natural conditions was clearly demonstrated, and suggest that those species can be of use in the culture of T. aestivum.Key words: Summer truffle; Tuber aestivum; truffle culture; truffle ecology; Pinus spp.; Quercus spp.

Fungi can strongly acidify their immediate soil environment and can cause a change in the equilibrium of soil carbonates. The Tuber melanosporum brule is an interesting biological model for studying soil reaction (pH) and decarbonation–recarbonation soil processes associated with ectomycorrhizal plants and soil fauna communities. Over the past 10 years ,we have observed that (1) a high concentration of active carbonate and exchangeable Ca2+ in the soil favors T. melanosporum fruiting body production and larger brules, (2) the amount of active carbonate is significantly higher and the total carbonate is significantly lower inside the T. melanosporum brule than outside the brule, (3) T. melanosporum ectomycorrhizae impact biodiversity and soil quality, and (4) the calciferous glands of Lumbricidae have an impact on soil reaction and carbonate availability in the brules. Here we propose new hypotheses on ectomycorrhizal fungal ecology, soil biology, and inorganic C soil sinks, suggesting that (1) the model that best explains the cause and effect of all brule observations is a feedback process; (2) this model assumes that T. melanosporum’s ability to modify soil properties has a direct impact on plant nutrition and degree of plant mycorrhization, and this hypothesis could have a considerable impact from the evolutionary standpoint of ectomycorrhizal fungi; and (3) the integrated action of T. melanosporum and/or other ectomycorrhizal fungal populations, and earthworms, could be of major importance in the cycling and sequestration of inorganic C in the soil.

Forest structure characterisation approaches using LiDAR data and object-based image analysis remain scarce to forestry agencies as these automated procedures usually require the use of expensive software and highly skilled analysts. The integration of forest expert opinion into semi-automated approaches would simplify the access of forest managers to new technologies and would allow the incorporation of personal experience and the introduction of specific forest management criteria. The aim of this study is to explore new alternatives to a previously published automated approach based on LiDAR data and object-based image analysis. We compare four approaches, ranging from null to high incorporation of expert opinion and from fully automated to fully manual. These four approaches consist of three stages: (1) forest stand identification from LiDAR models, (2) forest stand classification into forest structure classes (manual and based on cluster analysis), and (3) validation. Quantitative attributes for validation (i.e. hypsographs and percentiles) provided slightly lower degree of separability for forest structure classes, in the mixed procedures with increasing incorporation of expert opinion than for the fully automated approach. The new mixed approaches proposed are comparable to the automated procedures for the characterisation of forest structure in heterogeneous pine forest stands. They also offer additional advantages: (1) they make it possible to give a specific management focus and (2) they provide accessibility by the forest managers to the source of LiDAR information.

13 pages, figures, and tables statistics., In the jaragua-bahoruco-enriquillo biosphere reserve, located on the southern border between the Dominican Republic and Haiti, there are depressed rural areas with soils with high content in Cadmium and other heavy metals which originate naturally in the geological substrate. Data from 80 soils and an inventory of 76 plantations (coffee and kidney bean were used) to design a GIS (geographic information systems) tool which integrated statistical multivariate methods, soil parameters including heavy metal content into models of land planning, agricultural development, forests and protection of the health of the area’s inhabitants and the natural environment. This GIS tool is based on raster models of an open source, which use combination and reclassification operations based on the maps, geostatistical methods (Kriging), statistical analyses external to the GIS, and cartography of limiting and excluding particular factors for crops (including heavy metal soil content). The GIS tool developed discriminates extreme situations in sustainable agroforestry planning in contaminated rural areas of the Caribbean, Central America and other tropical regions., We would like to thank the economic support of Comunidad de Madrid: ‘‘EIADES Program’’, ‘‘Ana´lisis comparado de la planificacio´n territorial con base ecolo´gica entre Espan˜a e Iberoame´rica (P020715708)’’ and ‘‘Experiencia piloto de asesoramiento te´cnico por Internet de las contrapartes locales de la Cooperacio´n de la Comunidad de Madrid sobre evaluacio´n ambiental, planificacio´n territorial, desarrollo rural y prevencio´n de riesgos (P030715717)’’; the economic support of Spanish Ministry of Science and Innovation Projects: ‘‘CTM2005-02165/TECNO’’ and ‘‘CTM2008-04827/ TECNO’’; and the technical support of AECI: ‘‘Araucaria Programme’’. We thank I. Valverde support and P. Brooke- Turner translation.

The preservation of environmental quality is becoming recognised as a critical factor that should constrain landscape planning. Our objective is to develop an environmental assessment GIS raster tool (LATINO) for evaluating large territories, focused on SEA and screening of infrastructure planning procedures. We use GIS raster models based on logical operations of reclassifying and combining the raster layers, and numerical vector operations based on the vector module. We analyse a country of 506,000 km2, using a total of 102,240 different vectors. We use this model to estimate promptly the overall impact two Spanish infrastructure plans (PIT and PEIT) might have on the biodiversity and environment.

The ascocarps of several truffle species, such as Tuber rufum, are harvested in T. melanosporum brûlés; these species reduce T. melanosporum production. Some authors argue that this competition might be due to the evolution of organic matter in the soil. However, soil conditions in brûlés have yet to be clarified, and most studies on T. melanosporum fail to supply statistical data. We propose a study of 40 soils to compare the values for total organic carbon (TOC), pH, and carbonates inside the brûlés with the values for the outer edges of the same brûlés, where T. rufum ascocarps are collected. A principal component analysis relates the soils from the inner brûlés with high active carbonate content and soils outside the brûlés with high TOC and total carbonate content. ANOVA analyses indicate that the mean concentration of active carbonate, total CO32–, and % active/total carbonate differ significantly depending on soil location, but there are no significant differences for pH and TOC. These results lead us to propose a new hypothesis: T. melanosporum mycelia may solubilise active carbonate (50 μm) inside the brûlés; however the environmental conditions of the brûlés could favour a secondary carbonate precipitation with a net increase in active carbonate. This increase would counterbalance carbonate losses from leaching, which would in turn favour T. melanosporum mycelia, suggesting a feedback process.

Although soil is one of the factors in the biology of Tuber melanosporum (black truffle of Périgord), which has been the subject of much study, there are few quantitative analyses relating to its effects on carpophore production. The aim of this work is to establish the statistical relationship between T. melanosporum productivity in 20 soil surface horizons and their conventional soil properties (granulometric texture, pH, calcareous fractions, organic carbon, total nitrogen, exchangeable cations). The study area is situated in the centre of the Iberian Peninsula under a Mediterranean climate. Statistical analysis shows that the collective influence of these conventional soil features is low, as principal component analysis explains only 27% of the variance in T. melanosporum production. However, a high percentage of active limestone (calcium carbonate extractable with ammonium oxalate) accounts for 40% of the variance in T. melanosporum production. Active limestone is very important to T. melanosporum because it regulates soil pH and exchangeable Ca2+ availability and participates in the organisation and maintenance of the soil structure; it also plays a role in the truffle’s nutrition. These results obtained for active limestone may be of use in truffle cultivation.