Insect community response to switchgrass intercropping and stand age of loblolly pine (Pinus taeda) plantations

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Respiratory symptoms and lung function in taxi drivers and manual workers

The aim of this study, was to determine the prevalence of some respiratory symptoms and possible diseases among taxi drivers and manual workers. This prospective study was performed on 165 Pakistani male drivers, (mean age: 34.5±7.8 years) and 165 Pakistani male manual workers not exposed to dust or fumes, without occupational exposure to driving employed in the Water and Electricity Department and recruited as controls (mean age: 34.6±7.6 years and mean height and weight 169.8±6.0 cm and 71.9±10.9 kg). The data on chronic respiratory symptoms showed that taxi drivers had higher prevalence of symptoms than manual workers, being significantly greater for asthma (RR=1.72; 95% CI=1.00–2.88,P=0.037); allergic rhinitis (RR=2.41; 95% CI=1.46–3.94,P=0.0006); dyspnea (RR=2.13; 95% CI=1.22–3.71,P=0.009); and nasal catarrh (RR=2.19; 95% CI=1.22–3.91,P=0.0106). Thirty percent of taxi drivers and 27% of manual workers were smokers, there was no significant differences in the prevalence of chronic respiratory symptoms between smokers and non-smokers. Lung function parameters in the taxi drivers were significantly lower than in manual workers group (P<0.0001) except PEF parameter. When comparing the measured mean values of lung function parameters in the drivers among smokers and nonsmokers, there was no significant differences between smokers and nonsmokers. Also, a comparison of ventilatory capacity of paired predicted values with measured normal values showed statistically significant differences between predicted and measured values for taxi drivers and manual workers for FVC, FEV₁, FEF_25–75 and PEF parameters except for FEV₁/FVC test in manual workers. In conclusion, the results of the present study provide evidence regarding effects of such as carbon monoxide, nitrogen dioxide, sulfur dioxide and gases exposures on taxi drivers and long-term driving, which may be associated with the development of chronic respiratory symptoms and lung function impairment.     

A comprehensive synthesis of liana removal experiments in tropical forests

Lianas are a quintessential feature of tropical forests and are often perceived as being poorly studied. However, liana removal studies may be one of the most common experimental manipulations in tropical forest ecology. In this review, we synthesize data from 64 tropical liana removal experiments conducted over the past 90 yr. We explore the direction and magnitude of the effects of lianas on tree establishment, growth, survival, reproduction, biomass accretion, and plant and animal diversity in ecological and forestry studies. We discuss the geographical biases of liana removal studies and compare the various methods used to manipulate lianas. Overall, we found that lianas have a clear negative effect on trees, and trees benefitted from removing lianas in nearly every study across all forest types. Liana cutting significantly increased light and water availability, and trees responded with vastly greater reproduction, growth, survival, and biomass accumulation compared to controls where lianas were present. Removing lianas during logging significantly reduced damage of future merchantable trees and improved timber production. Our review demonstrates that lianas have an unequivocally detrimental effect on every metric of tree performance measured, regardless of forest type, forest age, or geographic location. However, lianas also appear to have a positive contribution to overall forest plant diversity and to different animal groups. Therefore, managing lianas reduces logging damage and improves timber production; however, the removal lianas may also have a negative effect on the faunal community, which could ultimately harm the plant community.     

Increasing the Efficiency of Microsatellite Discovery from Poorly Enriched Libraries in Coniferous Forest Species

Microsatellites are PCR based markers widely applicable in many plant species. Although the discovery and development of new microsatellites is a costly and technically demanding process, they are widely used in many plant systems. In coniferous tree species, the large genome size and repetitive DNA regions further aggravate the process, often resulting in libraries with very low enrichment efficiencies. Such species have proven intractable to efficient microsatellite discovery. For example, enriched microsatellite libraries produced for seven angiosperm species had enrichment efficiencies up to 50%, whereas libraries for three conifers, generated concurrently, under identical conditions, all had enrichment efficiencies below 10%. This report describes a simple strategy for recovering useful microsatellites from two of these conifer libraries, Pinus elliottii and Araucaria cuninghamii. Enrichment efficiencies increased from 0% to 100% and 1.5% to 98%, respectively. The strategy utilised DIG labelled oligo probes to identify clones containing microsatellite inserts. The technique is cost effective and rapid, utilising basic techniques and equipment that are widely available.     

Birds and people: from conflict to coexistence

Negative interactions between humans and animals are becoming increasingly frequent, as wild habitats shrink and human presence and activities expand throughout the world. Conflicts between people over conservation are one of the outcomes of this increased interaction, with severe consequences for both wildlife and people. Globally, conflicts can arise across diverse ecosystems, species and circumstances. Even if most attention in wildlife-related conflicts has been on mammals, birds are also often at the centre of such conflicts, but conflict research is still not explicitly present in ornithological literature. Examples of such conflicts include those related to birds and agriculture, forestry, hunting, fishing and public health interests. Conflicts are often more complex than initial assessments might suggest, involving ecological, economic, cultural, social and political elements. Reflecting the complexity of these issues and their increasing relevance to bird conservation, a British Ornithologists' Union conference was organized in November 2021 that aimed to highlight examples of conflicts that exist between people over birds and their conservation. Building on this conference, we provide here a review of key themes relating to the understanding of conflicts, including the importance of conflict perceptions, the collaboration between multiple disciplines and the different types of knowledge needed to better understand conflicts. We then consider the management of bird conservation conflicts, including the key issues of dealing with uncertainty, the role of technical solutions and the importance of collaboration and building trust, illustrating each theme with real-world examples. Finally, we outline potential future conflicts around bird conservation and how best to address them proactively.     

Assessing the biodiversity benefits of plantations: The Plantation Biodiversity Benefits Score

Summary   All forests, including commercial plantations, provide a range of habitats for conserving and enhancing elements of native biodiversity. However, the biodiversity values of commercial plantations will depend on the management practices adopted on site, as well as the landscape context of the plantation. The present study describes a generic, quantitative method for assessing the potential biodiversity benefits that might be derived from a plantation, depending on the management practices adopted. This method is based on existing ecological design and management principles. The Plantation Biodiversity Benefits Score (PBBS) was designed to be repeatable and practical to apply. The method can be used either as a stand-alone tool or as part of an integrated framework to assess and compare the commercial and environmental benefits that can be derived from different layouts, management practices and locations of plantations anywhere in Australia.     

Effects of Wildlife Forestry on Abundance of Breeding Birds in Bottomland Hardwood Forests of Louisiana

ABSTRACT Effects of silvicultural activities on birds are of increasing interest because of documented national declines in breeding bird populations for some species and the potential that these declines are in part due to changes in forest habitat. Silviculturally induced disturbances have been advocated as a means to achieve suitable forest conditions for priority wildlife species in bottomland hardwood forests. We evaluated how silvicultural activities on conservation lands in bottomland hardwood forests of Louisiana, USA, influenced species-specific densities of breeding birds. Our data were from independent studies, which used standardized point-count surveys for breeding birds in 124 bottomland hardwood forest stands on 12 management areas. We used Program DISTANCE 5.0, Release 2.0 (Thomas et al. 2006) to estimate density for 43 species with >50 detections. For 36 of those species we compared density estimates among harvest regimes (individual selection, group selection, extensive harvest, and no harvest). We observed 10 species with similar densities in those harvest regimes compared with densities in stands not harvested. However, we observed 10 species that were negatively impacted by harvest with greater densities in stands not harvested, 9 species with greater densities in individual selection stands, 4 species with greater densities in group selection stands, and 4 species with greater densities in stands receiving an extensive harvest (e.g., >40% canopy removal). Differences in intensity of harvest influenced densities of breeding birds. Moreover, community-wide avian conservation values of stands subjected to individual and group selection, and stands not harvested, were similar to each other and greater than that of stands subjected to extensive harvest that removed >40% canopy cover. These results have implications for managers estimating breeding bird populations, in addition to predicting changes in bird communities as a result of prescribed and future forest management practices.     

Comparisons of genetic parameters and clonal value predictions from clonal trials and seedling base population trials of radiata pine

Different methods for predicting clonal values were explored for diameter growth (diameter at breast height (DBH)) in a radiata pine clonal forestry program: (1) clones were analyzed with a full model in which the total genetic variation was partitioned into additive, dominance, and epistasis (Clone Only—Full Model); (2) clones were analyzed together with seedling base population data (Clone Plus Seedling (CPS)), and (3) clones were analyzed with a reduced model in which the only genetic term was the total genetic variance (Clone Only—Reduced Model). DBH was assessed at age 5 for clones and between ages 4 to 13 at the seedling trials. Significant additive, dominance, and epistatic genetic effects were estimated for DBH using the CPS model. Nonadditive genetic effects for DBH were 87% as large as additive genetic effects. Narrow-sense () and broad-sense () heritability estimates for DBH using the CPS model were 0.14 ± 0.01 and 0.26 ± 0.01, respectively. Accuracy of predicted clonal values increased 4% by combining the clone and seedling data over using clonal data alone, resulting in greater confidence in the predicted genetic performance of clones. Our results indicate that exploiting nonadditive genetic effects in clonal varieties will generate greater gains than that typically obtainable from conventional family-based forestry of radiata pine. The predicted genetic gain for DBH from deployment of the top 5% of clones was 24.0%—an improvement of more than 100% over family forestry at the same selection intensity. We conclude that it is best practice to predict clonal values by incorporating seedling base population data in the clonal analysis.