scispace - formally typeset
Search or ask a question

Showing papers by "Adrian C. Newton published in 2008"


Journal ArticleDOI
TL;DR: In this paper, the authors have presented a study that has been financed by the projects: EU INCO Programme (this paperORLAN: EUINCO-CT-2006-032132), UE Alpha Programme II-0411-FA-FCD-FI-FC, Spanish Ministry of Science and Education CGL2004-00355/BOS, Madrid Government S-0505/AMB/0355(REMEDINAL), and UK RELU Award 227/0010 “FarmCAT”.
Abstract: This research has been financed by the projects: EU INCO Programme (REFORLAN: EU INCO-CT-2006- 032132), UE Alpha Programme II-0411-FA-FCD-FI-FC, Spanish Ministry of Science and Education CGL2004-00355/BOS, Madrid Government S-0505/AMB/0355 (REMEDINAL), and UK RELU Award 227/0010 “FarmCAT”.

353 citations


Journal ArticleDOI
TL;DR: In this article, the current and future impacts of fragmentation on spatial configuration of forest habitats at the landscape level time in southern Chile were studied using both a GIS-based land-use change model (GEOMOD) and spatially explicit logistic regression.

167 citations


Journal ArticleDOI
TL;DR: In this paper, three monitoring methods were assessed in two N2000 sites, the Foresta del Cansiglio (IT) and the New Forest (UK): (i) sample plots, (ii) a point-transect method and (iii) a visual assessment method.

76 citations


Journal ArticleDOI
01 Apr 2008-Oryx
TL;DR: In this paper, the authors examined the reasons why the conservation-through-use approach is rarely successful in practice, and highlighted the importance of understanding the interactions between threats for conservation through use to be achieved.
Abstract: Tree species have been the focus of increasing interest regarding the so-called conservation-through-use approach, which aims to achieve conservation by increas- ing the value of wild resources to local communities. Although tree species display many characteristics that increase their potential for sustainable use, the approach is rarely successful in practice. The reasons for this are examined with reference to case studies, considering five conditions needed for success: (1) sustainable harvesting, (2) no interaction between threats, (3) successful commer- cialization, (4) economic benefits received by producers, and (5) use of financial income to support conservation action. Case studies illustrate that even when the first four of these conditions are met, trade in forest products often provides insufficient financial returns to protect the forest against other threats. This highlights the importance of understanding the interactions between threats for conser- vation-through-use to be achieved, an issue illustrated by a conceptual model. Recommendations are presented in- dicating how the conservation of tree species through sus- tainable use may be achieved in practice. Critically, financial rewards of sustainable use need to be large enough to support practical conservation action, which is required to counter the many threats to which tree species are exposed.

62 citations


Journal ArticleDOI
TL;DR: Attempts to use the RL to support global monitoring of biodiver- sity appear premature, and much greater support needs to be given to collection of primary field data and expert knowledge to accurately ascertain the current status of the world's threatened tree species.
Abstract: The IUCN (International Union for Conservation of Nature) Red List of Threatened Spe- cies™ (RL) is widely recognised as an authoritative assessment of the conservation status of species, yet its coverage is uneven and incomplete. Trees account for approximately 20% of taxa currently included, but most of these were listed a decade ago. Over the last 10 yr, only 879 taxa have been added to the RL database, representing 11% of the number listed in 1998. However, progress has not been as limited as these data suggest. Ten recent assessments of different groups of trees are pro- filed, and the lessons learned from these assessments are summarised. In total, these assessments have evaluated >2500 tree taxa, but only a fraction of these have been added to the RL database, rais- ing concerns about the process of data management. Results indicated that a mean of 42% taxa were classified as threatened. Information on the status and distribution of most tree species is severely lacking, a situation compounded by taxonomic confusion in many groups. As a result, RL assessments will continue to be highly dependent on expert knowledge originating from herbarium data, which, as demonstrated here, tends to result in a relatively high proportion of taxa being listed under RL Cri- teria B1 and B2. Given this situation, attempts to use the RL to support global monitoring of biodiver- sity appear premature, and much greater support needs to be given to collection of primary field data and expert knowledge to accurately ascertain the current status of the world's threatened tree spe- cies.

43 citations


Journal ArticleDOI
TL;DR: It was found that under O. xalapensis trees the breakdown of lignin from the litter produced by the same species of tree was particularly effective, suggesting that a feedback has developed between this tree species and the decomposer community prevailing under its canopy.
Abstract: This paper tests whether individual trees in a mature forest stand influence the process of litter decomposition and the macroinvertebrate communities in the soil underneath their canopies, as a result of species-specific characteristics. A field decomposition experiment was performed in a mature forest stand of tropical montane cloud forest in Mexico. The areas under the canopies of Quercus laurina Humbl. & Bompl., Oreopanax xalapensis (Kunth) Decne. & Planchon and Beilschmedia ovalis (Blake) C. K. Allen trees were used as experimental units. The natural soil and litter macroinvertebrate communities were monitored and compared to the community that invaded decomposition boxes with reciprocally transplanted leaf litter. The abundances of four macroinvertebrate taxa in natural litter differed among tree species independently of season. No differences were found in the soil community. The response to experimental litter by macroinvertebrate taxa suggests that the production of a specific quality of litter is an important mechanism by which a tree influences the litter macroinvertebrate community that develops under its canopy. However, not all differences in community composition naturally found between tree species can be explained by differences in litter quality during the first year of decomposition. Differences in nutrient release that occur after the first year, and physical properties of litter also probably play an important role. Independently of the canopy tree, the initial chemical quality (N, P, Ca, Mg and lignin) of experimental litter largely determined the decomposition rate and nutrient dynamics of decomposing leaves. However, it was found that under O. xalapensis trees the breakdown of lignin from the litter produced by the same species of tree was particularly effective. This suggests that a feedback has developed between this tree species and the decomposer community prevailing under its canopy.

43 citations



Journal ArticleDOI
TL;DR: In this article, seven winter barley cultivar monocultures and all their equal proportion mixtures were trialled and data analysed by ANOVA, REML and principal component analyses to determine the contribution of particular varieties or combinations to crop performance.
Abstract: BACKGROUND: Mixtures of cereal cultivars grown together generally enhance yield and reduce disease but end-users will not accept them for quality uses. Some combinations with very different quality may be problematic, others complementary. The common origin of Maris Otter for quality in winter barley may enable the benefits of complex mixtures to be exploited without quality compromises. RESULTS: Seven winter barley cultivar monocultures and all their equal proportion mixtures were trialled and data analysed by ANOVA, REML and principal component analyses to determine the contribution of particular varieties or combinations to crop performance. Agronomic yield was positively correlated with component number. Pipkin contributed negatively to thousand grain weight (TGW), but positively to several quality traits; Gleam negatively to the same quality traits but strongly positively to yield; and Melanie combined strong yield and TGW characteristics with neutral quality traits. Interactions in mixtures with Maris Otter, from which most of the cultivars are likely to derive some of their quality traits, were less apparent for quality than for yield. CONCLUSIONS: Complex mixtures gave yield benefits generally without compromising quality, and analysis methods were developed to identify the beneficial or negative effects of component cultivars on malting quality traits, thereby providing data for optimising mixtures design. Copyright © 2008 Society of Chemical Industry

22 citations



Journal ArticleDOI
TL;DR: Results are consistent with recent evidence suggesting that some endemic plant taxa are able to maintain relatively high diversity within populations despite the occurrence of inbreeding and genetic drift, and that species with wider geographic ranges tend to exhibit relatively high genetic differentiation among populations.
Abstract: Abstract Patterns of genetic variation were examined within two endemic tree species restricted to Mexican cloud forest, Magnolia sharpii and Magnolia schiedeana. Leaf samples collected from natural populations were analysed using PCR RFLP of cpDNA, Inter-SSR and isozyme genetic markers, which were used to test a series of hypotheses regarding patterns of intraspecific variation within the two species. Genetic diversity estimates derived from Inter-SSR markers (mean Spop of 0.56 and 0.50 for M. sharpii and M. schiedeana respectively) are comparable to values obtained for other tree species. As predicted on the basis of its larger geographic range, the degree of population differentiation was found to be higher within M. schiedeana than M. sharpii, with 12.9% and 3.4% of total variation recorded between populations for the two species respectively using isozymes, and 26% and 11% using Inter- SSR markers. Isozyme analyses indicated negative Fis values, which may be suggestive of inbreeding in populations of M. sharpii, but provided less evidence of inbreeding in M. schiedeana. On the basis of PCR RFLP analysis of cpDNA, two chloroplast types were differentiated, type A being recorded for all of the individuals of both species, with the exception of one population of M. schiedeana that was fixed for type B. These results are consistent with recent evidence suggesting that some endemic plant taxa are able to maintain relatively high diversity within populations despite the occurrence of inbreeding and genetic drift, and that species with wider geographic ranges tend to exhibit relatively high genetic differentiation among populations. Conservation strategies for these species need to take into account the significant genetic differences recorded among the populations studied.

19 citations


Journal ArticleDOI
TL;DR: In this paper, the authors identify appropriate indicators to maintain favourable conservation status, and to evaluate their relative cost-effectiveness for two selected Natura 2000 sites: the Cansiglio Forest (North Italy) and the New Forest (South England).
Abstract: Natura 2000 is a coherent ecological network of special areas, designated under the Habitat and Birds EEC Directives, to assist in the maintenance of biodiversity in the European territory. It is now widely recognised that one of the most effective ways to maintain biodiversity is to preserve habitats in a favourable conservation status as required of Member States by the Habitat Directive. As a consequence, approaches are needed to define when habitats are of favourable conservation status and to assess the maintenance or the restoration of this condition. This could be partly achieved through the selection of appropriate indicators of favourable conservation status. Once such indicators have been identified and tested, they could be used for monitoring the impact of managing Natura 2000 sites, and could assist in achieving policy goals. Although many indicators have been proposed, particularly for forested habitats, few have been adequately field tested. Little research has been undertaken to identify indicators that are cost-effective, a key characteristic given that resources for habitat assessment and monitoring are often limited. Therefore, this research aims both to identify appropriate indicators to maintain favourable conservation status, and to evaluate their relative cost-effectiveness for two selected Natura 2000 sites: the Cansiglio Forest (North Italy) and the New Forest (South England). The following will highlight the results of the preliminary research.Natura 2000 is a coherent ecological network of special areas, designated under the Habitat and Birds EEC Directives, to assist in the maintenance of biodiversity in the European territory. It is now widely recognised that one of the most effective ways to maintain biodiversity is to preserve habitats in a favourable conservation status as required of Member States by the Habitat Directive. As a consequence, approaches are needed to define when habitats are of favourable conservation status and to assess the maintenance or the restoration of this condition. This could be partly achieved through the selection of appropriate indicators of favourable conservation status. Once such indicators have been identified and tested, they could be used for monitoring the impact of managing Natura 2000 sites, and could assist in achieving policy goals. Although many indicators have been proposed, particularly for forested habitats, few have been adequately field tested. Little research has been undertaken to identify indicators that are cost-effective, a key characteristic given that resources for habitat assessment and monitoring are often limited. Therefore, this research aims both to identify appropriate indicators to maintain favourable conservation status, and to evaluate their relative cost-effectiveness for two selected Natura 2000 sites: the Cansiglio Forest (North Italy) and the New Forest (South England). The following will highlight the results of the preliminary research.

Journal ArticleDOI
TL;DR: It is concluded that the decomposition and associated biota differ between successional stages, and other factors associated with the age of the forest, such as small differences in soil temperature and long-lasting effects of disturbance, may also play influential roles.
Abstract: This paper presents the results of a decomposition experiment performed in a secondary chronosequence of tropical montane cloud forest in Mexico. The experiment was designed to explore whether the age of the forest influences the decomposition process and macroinvertebrate community independently of the quality of the decomposition resources. Fresh Pinus chiapensis needles and Persea americana leaves were set to decompose in each of four successional stages (15, 45, 75 and 100 years old). Results do not support the hypothesis that decomposition rate declines with increasing nutrient deficiency as forest succession proceeds. However, the chemical composition in decomposing leaves differed between successional stages. Higher availability of Ca in the 15-year-old forest appears to promote a positive feedback in the release of this nutrient from Persea americana leaves. Additionally, in old forests, a soil community that is more capable of breaking down recalcitrant material (acid detergent lignin) appears to have developed compared to early successional stages. The diversity of macroinvertebrates and abundance of predatory (Aranea and Diplura), detrivorous (Diplopoda) and geophagous (Enchytaeidae) taxa were different between boxes placed in different successional stages. We conclude that the decomposition and associated biota differ between successional stages. Apart from differences in litter quality, other factors associated with the age of the forest, such as small differences in soil temperature and long-lasting effects of disturbance, may also play influential roles.

01 Jan 2008
TL;DR: In this article, complex interactions between pests, pathogens, their hosts and abiotic stresses are studied to appropriately exploit the germplasm resources available for developing future crops for food security.
Abstract: Climate change, longer growing seasons, precipitation changes, more extremes and higher temperatures will mean future crops need to be more resilient. Soils are an important resource, a complex community and a potential carbon sink which will be affected by and respond to these changes. Understanding the complex interactions between pests, pathogens, their hosts and abiotic stresses is necessary to appropriately exploit the germplasm resources available for developing future crops. There are important implications for our food security but these too comprise complex interactions.



01 Jun 2008
TL;DR: In this article, the authors revisamos the principales enfoques for the restauración of forests and evaluamos las fortalezas and debilidades of the modelo of islotes forestales in mares agricolas.
Abstract: Diferentes iniciativas de restauracion pretenden mitigar la vasta deforestacion y degradacion forestal existentes en el mundo. La “restauracion pasiva”, en la cual los campos agricolas abandonados son sujeto de la sucesion secundaria, es con frecuencia lenta debido a limitaciones bioticas y abioticas. La “restauracion activa”, basada sobre todo en la plantacion de arboles, puede ser cara si se restauran territorios amplios. Sugerimos la utilizacion de “islotes forestales” como una alternativa para la restauracion de paisajes agricolas extensos, particularmente en ambientes de productividad baja. Este enfoque implica la plantacion de numerosos y densos nucleos de vegetacion lenosa nativa que incrementan la biodiversidad y proporcionan una variedad de servicios ambientales. Si los campos de alrededor son abandonados, los islotes actuan como fuentes de propagulos de especies forestales, acelerandose el desarrollo de los matorrales y bosques. Por el contrario, si los campos de alrededor son utilizados para cultivos y pastos, los islotes pueden incrementar el valor de conservacion del paisaje y ofrecer un potencial de generacion de rentabilidad economica. En este trabajo revisamos los principales enfoques para la restauracion forestal y evaluamos las fortalezas y debilidades del modelo de los islotes forestales en mares agricolas.