Native Woodland Research Articles

Restored and remnant Banksia woodlands elicit different foraging behavior in avian pollinators.

Pollinators and the pollination services they provide are critical for seed set and self‐sustainability of most flowering plants. Despite this, pollinators are rarely assessed in restored plant communities, where their services are largely assumed to re‐establish. Bird–pollinator richness, foraging, and interaction behavior were compared between natural and restored Banksia woodland sites in Western Australia to assess their re‐establishment in restored sites. These parameters were measured for natural communities of varying size and degree of fragmentation, and restored plant communities of high and low complexity for three years, in the summer and winter flowering of Banksia attenuata and B. menziesii, respectively. Bird visitor communities varied in composition, richness, foraging movement distances, and aggression among sites. Bird richness and abundance were lowest in fragmented remnants. Differences in the composition were associated with the size and degree of fragmentation in natural sites, but this did not differ between seasons. Restored sites and their adjacent natural sites had similar species composition, suggesting proximity supports pollinator re‐establishment. Pollinator foraging movements were influenced by the territorial behavior of different species. Using a network analysis approach, we found foraging behavior varied, with more frequent aggressive chases observed in restored sites, resulting in more movements out of the survey areas, than observed in natural sites. Aggressors were larger‐bodied Western Wattlebirds (Anthochaera chrysoptera) and New Holland Honeyeaters (Phylidonyris novaehollandiae) that dominated nectar resources, particularly in winter. Restored sites had re‐established pollination services, albeit with clear differences, as the degree of variability in the composition and behavior of bird pollinators for Banksias in the natural sites created a broad completion target against which restored sites were assessed. The abundance, diversity, and behavior of pollinator services to remnant and restored Banksia woodland sites were impacted by the size and degree of fragmentation, which in turn influenced bird–pollinator composition, and were further influenced by seasonal changes between summer and winter. Consideration of the spatial and temporal landscape context of restored sites, along with plant community diversity, is needed to ensure the maintenance of the effective movement of pollinators between natural remnant woodlands and restored sites.

Glechoma hederacea (Lamiaceae): Key features in its native range, habitats, cultural significance, impacts and sustainability status

The existence and sustainability of the ethbotanical plant species are among the most important resources for the world, especially considering hunger and economic contribution. Moreover, with the use of wild plant species for human and animal health for medical purposes, these plants’ importance are increasing. Therefore social awareness is important for the effective and sustainable use of the relevant species. The main reason for the emergence of this study is this social awareness. Here, we worked on Glechoma hederacea L., which we registered for the first time in Düzce in 2019 due to the environmental and socioeconomic impacts reported to us by the local people. The aims of this study to present the existence of G. hederacea, its habitats, some morphological, phenological data and the impact of the ethnobotanical use of the plant on its sustainability in native range. For this purpose, the plant was followed in Düzce central district between July 2019 and May 2020. As a result, it was determined that G. hederacea started flowering in March in Düzce and the flowering continued until the end of November. In Düzce, which is built on a plain, it has been determined that G. hederacea was widespread primarily in pastures, natural open areas, roadsides, open woodlands, tree edges, agricultural and urban habitats. Moreover, for the sustainability of the plant, it has been determined that villagers take some sub-regional measures against vegetation removal and even carry out small activities for plant propagation. However, the ratio between harvesting rate and planting is not sufficient. Considering this situation, awareness activities for G. hederacea as well as other plant species with ethnobotanical use and, when necessary, encouraging the production of the relevant native species for medical purposes will be useful.

Ethnobotany of an indigenous tree Piliostigma thonningii (Schumach.) Milne-Redh. (Fabaceae) in the arid and semi-arid areas of South Omo Zone, southern Ethiopia

BackgroundTrees are important components of terrestrial ecosystems; they provide ecological, economic, and cultural services to humans. There is an urgent need for undertaking ethnobotanical investigations and documentation on the indigenous botanical knowledge of the local communities of a given area. This study was conducted to assess and document the categoric ethnobotany of Piliostigma thonningii and the associated indigenous knowledge of the local people related to use, management practices, and the threatening factors in the South Omo Zone of southwestern Ethiopia.Materials and methodsSix Kebeles were purposively selected from two districts of the zone and a total of 84 respondents were sampled, with consideration of gender, age, and wealth status. Data were collected using structured and semi-structured interviews, field observations, and group discussions. Relevant descriptive statistical methods were used to analyze the data. Ethnobotanical knowledge held by informants were computed using Pearson’s chi-square test and direct matrix ranking and pair-wise ranking was used to prioritize the uses according to community preferences and the level of the destructiveness of the reported threats.ResultsThe results showed that P. thonningii provides different functions to people’s livelihoods as shade, food, fodder, soil fertility, fuelwood, medicine, rope, multipurpose materials (e.g., Borketa for sitting and head support), huts, beehives, farm implements, chairs, fences, and timber. The indigenous knowledge of local people on the uses of P. thonningii has shown significant (P < 0.05) relationship to age groups (being higher for elderly people). The consumption practice of respondents has significant (P < 0.05) association to the Kebeles, age, and income, with higher value for Hamer, lower aged groups, and low-income families. It provides nutritious animal feed to improve browse intake, survival, and productivity of domestic animals and also improve productivity of farm through amelioration of soil fertility. The status of P. thonningii has been decreasing due to agricultural expansion, collection of the species for firewood, dry fencing, and due to browsing. Respondents’ attitude and interest to maintain and conserve the species has shown a significant (P< 0.05) association to gender, wealth, and level of education. Higher interest was observed in men than women, mid-high wealth class households than low income, and people with education than uneducated.ConclusionsThis study attempted to provide information on the multiple uses of P. thonningii. Given the key roles of P. thonningii for the people and the environment to improve household food security, agricultural productivity, and income sources and the threats to it, the need to protect it in natural forests and woodlands and optimize its uses in agroforestry systems is high. Serious consideration of this species will ultimately allow households to reap the benefits expected to accrue from it in the arid and semi-arid areas of Ethiopia where plants of this nature are usually rare.

Exploring the biotic homogenization and diversity resistance hypotheses: The understorey of non‐native and native woodland canopies in three urban areas of Europe

AbstractAimExploring the biotic homogenization and diversity resistance hypotheses by assessing the effect of non‐native black locust canopy on understorey species turnover.LocationBerlin, the Venetian metropolitan area, and Rome.MethodsWe modelled the zeta (ζ) expression of diversity to compare the understorey species turnover between the non‐native black locust and native woodland canopies across multiple sites and through predictors of anthropogenic pressure (road and built‐up density) and interior conditions (tree basal area and mean height).ResultsIn Rome, black locust showed the lowest survivability and cover and did not produce any homogenization of the understorey. In Berlin and in the Venetian metropolitan area, black locust caused understorey homogenization, although with a lower intensity in Berlin. Under black locust canopies, distance between sites and road density was more consistently associated with species turnover, across urban areas and multiple sites. Under native canopies in Berlin, factors prominently associated with species turnover were road and built‐up density and mean tree height, while in the Venetian metropolitan area it was road density.Main conclusionsEvidence in support of the biotic homogenization in contrast to the diversity resistance hypothesis varied across urban areas. Species turnover was influenced by land use patterns more evidently under native tree canopies and where the non‐native tree had higher survivability. Similar analyses in other urban areas may confirm these relationships with other types of landscapes.

Can epiphytic lichens of remnant Atlantic oakwood trees in a planted ancient woodland site survive early stages of woodland restoration?

Key messageEpiphytic lichens of remnant Atlantic oakwood trees, enclosed within a recently planted conifer matrix, show ability to survive early stages of woodland restoration (conifer removal).ContextAtlantic oakwood, ancient semi-natural woodland (ASNW), supports important epiphytic lichens. Fragmented ASNW, historically in-filled with conifers, are now being restored to reflect ASNW tree and ground flora character. Concerns exist that sudden and total removal of the conifer matrix will be detrimental to the epiphyte diversity of remnant trees retained within the former plantation.AimsHere, we ask whether an unintended consequence of habitat restoration is the loss of epiphyte populations on remnant trees.MethodsDynamics of ground flora development were studied at one 50-ha site on the west coast of Scotland using indicator species occurrence and species traits. Change in cover of lichen species was determined and lichen vitality was assessed in two Lobaria species using chlorophyll fluorescence as a proxy. Assessments pre-, post- and nine years after conifer removal were made in plantation areas (containing remnant oak trees) and ASNW areas.ResultsRe-vegetation of the ground flora was predominantly by ASNW vegetation. Species richness and occurrence of native woodland indicator species increased and the community showed stronger competitor traits. Lichen vitality was initially reduced but recovered. Tests showed change in the abundance of key lichen species and lichen community diversity was non-significant despite the loss of four lichen species on remnant trees.ConclusionGround flora dynamics indicate site recovery was underway within eight years of restoration activities and epiphytic lichens although variable in response were in this study largely unaffected, this restoration approach could be appropriate for other Atlantic oakwoods where lichen conservation is an objective.

Long-term woodland restoration on lowland farmland through passive rewilding.

Natural succession of vegetation on abandoned farmland provides opportunities for passive rewilding to re-establish native woodlands, but in Western Europe the patterns and outcomes of vegetation colonisation are poorly known. We combine time series of field surveys and remote sensing (lidar and photogrammetry) to study woodland development on two farmland fields in England over 24 and 59 years respectively: the New Wilderness (2.1 ha) abandoned in 1996, and the Old Wilderness (3.9 ha) abandoned in 1961, both adjacent to ancient woodland. Woody vegetation colonisation of the New Wilderness was rapid, with 86% vegetation cover averaging 2.9 m tall after 23 years post-abandonment. The Old Wilderness had 100% woody cover averaging 13.1 m tall after 53 years, with an overstorey tree-canopy (≥ 8 m tall) covering 91%. By this stage, the structural characteristics of the Old Wilderness were approaching those of neighbouring ancient woodlands. The woody species composition of both Wildernesses differed from ancient woodland, being dominated by animal-dispersed pedunculate oak Quercus robur and berry-bearing shrubs. Tree colonisation was spatially clustered, with wind-dispersed common ash Fraxinus excelsior mostly occurring near seed sources in adjacent woodland and hedgerows, and clusters of oaks probably resulting from acorn hoarding by birds and rodents. After 24 years the density of live trees in the New Wilderness was 132/ha (57% oak), with 390/ha (52% oak) in the Old Wilderness after 59 years; deadwood accounted for 8% of tree stems in the former and 14% in the latter. Passive rewilding of these ‘Wilderness’ sites shows that closed-canopy woodland readily re-established on abandoned farmland close to existing woodland, it was resilient to the presence of herbivores and variable weather, and approached the height structure of older woods within approximately 50 years. This study provides valuable long-term reference data in temperate Europe, helping to inform predictions of the potential outcomes of widespread abandonment of agricultural land in this region.

Assessing natural resource change in Vhembe biosphere and surroundings.

South Africa is a custodian of an immense wealth of natural and biodiversity resources in Africa. Natural resources are continually changing in different South African biospheres based on anthropogenic and non-anthropogenic causes. Land use activities like agriculture, cultivation, livestock rearing, commercial plantations, urbanisation and mining are among the major drivers of natural resource change and transformation. In this study, land cover change assessment was used to assess natural resource change in Vhembe biosphere and surroundings. To assess natural resource change in Vhembe biosphere, land use land cover change assessment was conducted using South African's national land-cover dataset, generated from multi-seasonal Landsat 5 and Sentinel-2 images. The 72× class land cover map was re-classified into 12× classes to fit the study objectives. Eight out of twelve classes quantified in hectares: indigenous forests, thicket/dense bush, natural woodland, shrubland, grassland, water bodies and wetlands were categorised as natural resources for which the natural resource change assessment for this study was based. Assessment findings established that land use and its related activities have contributed substantially to natural resource change where cultivated commercial, natural woodland and built-up residential contributed the most significant upward change in hectarage and percentage, from 132,246.9 to 365,644.92 (ha)-percentage change of 176%; from 94,665.42 to 257,889.68 (ha)-percentage changes of 172% and from 74,070.27 to 147,701.88(ha)-percentage change of 99% respectively. Shrubland, thicket/dense bush and indigenous forests registered the highest downward changes from 263,070.6 to 977.72 (ha); from 338,723.7 to 23,166.92 and from 13,211.91 to 7402.92 (ha) with percentage changes of -100%, -93% and -44% respectively in Vhembe biosphere and the surroundings from 1990 to 2018. The study showed how natural resources are changing and the use of remote sensing for environmental monitoring and assessment in the Vhembe district.

The long-term development of temperate woodland creation sites: from tree saplings to mature woodlands

Abstract Tree planting is at the forefront of the current environmental agenda to mitigate climate change and tackle the biodiversity crisis. In the United Kingdom (UK), tree planting has been a priority for more than a century and has helped increase woodland cover from a historic low of 5 per cent at the beginning of the 20th century to a current figure of 13 per cent. However, we still know relatively little about the long-term development of woodland creation sites (particularly of native woodlands) over ecologically realistic timescales. We surveyed a chronosequence of 133 temperate woodland patches encompassing 106 woodland creation sites (10–160 years old) and 27 mature ‘ancient’ woodlands (&amp;gt;250 years old), using a combination of field surveys and remote sensing techniques to quantify vegetation structural changes associated with woodland development. Woodland creation sites displayed similar vegetation development patterns to those described for other woodland systems, i.e. a gradual transition as woodlands undergo ‘stand initiation’, ‘stem exclusion’ and ‘understorey re-initiation’ stages, and became more similar to ‘ancient’ woodlands over time. Structural heterogeneity, average tree size and tree density were the attributes that varied the most among woodland developmental stages. In general, structural heterogeneity and average tree size increased with woodland age, whilst tree density decreased as would be expected. Younger sites in stand initiation were strongly dominated by short vegetation, stem exclusion sites by taller trees and older sites had a more even vegetation height distribution. There was a large degree of overlap between the vegetation characteristics of woodlands in understorey re-initiation stages and older ancient woodlands (partly driven by a lack of regeneration in the understorey); these results suggest that it takes between 80 and 160 years for woodland creation sites to develop certain vegetation attributes similar to those of mature ancient woodlands included in this study. Woodland management practices to create canopy gaps and reducing grazing/browsing pressure to promote natural regeneration are likely to accelerate this transition, increase the structural heterogeneity and biodiversity value of woodland creation sites and enable adaptation and resilience to climate change.

Role OF Structural Indices and Other Spatial Measures in the Improvement Of Crown Variables Prediction For Lannea fructicosa

Theoretically, the stem of the tree must be strong enough to withstand the forces that act on it. These forces include the weight of the crown and the drag exerted on it by the wind. This mean that for a well-established root system, there should be some kind of balance between crown and stem sizes, otherwise the stem be break. The sizes, shapes and relative locations of crowns both determine and respond to the shading and constriction effects that characterize aboveground interactions between trees. Due to this kind of balance, tree crown parameters have been used as predictor variables in diameter and height growth equations. Although the correlation between tree variables and crown dimensions has well documented in the literature, other stand composition and conditions such as competition, elevation and aspect are believed to be among the unexplained forces that exert strong influences on the accuracy of the allometric models used for that relationship. This study attempted to quantify the effect of structural indices and other spatial measures to improve the prediction of crown radius and crown length for trees in natural woodlands. Field data were recorded for Lannea fruticosa tree species that naturally grown in Elgarri forest reserve in Blue Nile State, Sudan. The data was used to test the performance of estimating crown dimensions on the basis of allometric relationships with tree diameter and height. A total of thirteen spatial and non-spatial indices were incorporated into modified crown dimension models. Coefficient of multiple determination (R2) and relative bias were used to test the performance of these indices in improving the accuracy of estimates. According to the results all predictions of crown length and radius were found to be better after the incorporation of the spatial and non-spatial, with positive R2 gain and acceptable negative bias values for crown radius and positive ones for crown length. For all cases, the spatial indices were found to be better than the non-spatial ones.

Katniss’ Savior: Wilderness in Suzanne Collins’s 'The Hunger Games'

From many discussions on wilderness in literary works, only a few focus on the young adult dystopian, even more on Suzanne Collins’s The Hunger Games. For this reason, this article aims to portray the wilderness in the book as the survival resource since the previous studies fail to point out such an issue. This recent study is conducted by descriptive qualitative methods. As the theoretical basis, the discussion employs Garrard’s account of wilderness and Ross’s myth of wilderness in American literature. As a result, the discussion depicts the wilderness as the natural woodland surrounding District 12 and the artificial battleground of the Games in Panem. The woods in Katniss’s district enable her to provide for her family and develop such literacy in the wilderness. This literacy is advantageous in the Games arena, thus helps Katniss to be one of the winners. The findings might provide such an insight to the reader to live harmoniously with nature, even more with the wilderness.

The carbon sequestration potential of Scottish native woodland

Woodland creation sequesters carbon and contributes to climate change mitigation. Most previous assessments of the carbon sequestration of new UK woodlands have focused on tree planting, little is known about the scale of the potential contribution from natural regeneration. We used a Potential for Native Woodland Model to make the first estimate of carbon sequestration by large-scale native woodland expansion through natural regeneration in Scotland. We estimate native woodland could expand to cover an additional 3.9 million hectares of the Scottish uplands removing an average of 6.96 million tons of CO2 per year. This represents 35%–45% of the carbon removal target for UK woodlands that has been suggested by the UK Committee on Climate Change. Expanding woodlands to just 10% of this potential would double existing native woodland and could provide a multitude of benefits, including carbon removal equivalent to approximately 4% of this target. The next few decades are critical in terms of climate change mitigation, therefore further work is now required to improve these estimates and better constrain this potentially large contribution.

Assessment of earthworms as an indicator of soil degradation: A case‐study on loess soils

AbstractSoil degradation restricts the development of agriculture, and the degree of soil degradation is related to land use type, and efficient evaluation methods are helpful for the timely implementation of remedial measures to ensure soil sustainability. Earthworms are directly affected by the deterioration of soil properties during the degradation process. The feasibility of using earthworms to assess soil degradation, however, still needs to be verified. In our Loess Plateau study, earthworm biomass, density, and diversity (Shannon‐Wiener, species richness, and Pielou's evenness) were investigated under nine different land use types (natural woodland, shrubland and grassland; planted woodland, shrubland and grassland; and cropland, orchard, abandoned land) and we analyzed their relationships with soil degradation. Our results showed earthworm biomass, density, and diversity associated with a low degree of degradation were significantly higher than those associated with a high degree of degradation. Earthworms can comprehensively characterize the physicochemical properties and biological characteristics of soils under different land use types. Linear correlations showed a significant relationship between the soil degradation index and the earthworm indices, indicating that the latter could be used to effectively evaluate and represent the degree of degradation of soils on the Loess Plateau over a certain degradation range. Nevertheless, this evaluation method requires further validation before wider use.

Multivariate Modelling for the Unexplained Relationships of tree Variables for Combretum hartmannianum

Tree crown information contributes to the investigation of several key forest ecosystem attributes: biodiversity, productivity, sustainability, aesthetics, forest environment and wildlife. Recent remote sensing applications utilize estimation of either canopy cover or individual tree canopy area as a first stage towards timber volume. Measurement of CR size for each tree can be time-consuming and difficult to obtain in very dense stands and for very tall trees where the base of live crown is obscured. Studies have often shown that abiotic factors such as soil and topographic characteristics play a major role for species distribution. Moreover, space has been shown to be more important than environment in determining woody plant species distribution. However, trees show considerable variation and flexibility in their size of crowns, height and stem diameters. The tree stem size has its own adaptive significance to a tree. It must be strong enough to withstand the forces that act on it (weight of the tree and the drag exerted on it by the wind). The sizes, shapes and relative locations of crowns both determine and respond to the shading and constriction effects that characterize aboveground interactions between trees. The more important issue is that, whether stem diameter-at-breast height relationships with tree height, crown height, and crown diameter are the only factors that can be used to model growth and yield of trees, especially in case of natural forests and or mixed plantations with different species and sizes. This study investigates the potential for structural indices and other spatial measures to improve the prediction of crown radius and crown length for trees in natural woodlands. Field data were collected for Cambretum hartmannianum tree species from Elgarri natural forest reserve in Blue Nile State, Sudan, to test the performance of crown radius and crown length (height) models on the basis of allometric relationships with stem dimensions. A number of spatial and non-spatial variables were incorporated into modified crown dimension models. Coefficient of determination (R2) and relative bias were used to test the performance of the inclusion of spatial or non-spatial variables into the original models (using tree dimensions alone). Predictions of crown length and radius were found to be better after the incorporation of the spatial and non-spatial. Our results also confirm that not all estimation models are suitable for all forest, but subject to the local forest condition and composition. In this regard and for the studied tree species in the selected forest, Mi index is recommended for the estimation of crown radius, and DCL index for crown length.

Exploration of unconventional oil and gas (UOAG) development on farmland: Findings from the Bakken shale of North Dakota

Few studies have examined the land use, fragmentation, and conversion impacts from siting unconventional oil and gas wells on farmland. This exploratory GIS study examined these issues in the Bakken shale region in North Dakota. A total of 3,577 well pads containing 6,201 wells located on farmland were digitized and examined in this study. The findings indicate that in addition to land used for agricultural purposes (such as cropland and rangeland), other land types such as native woodlands and wetlands have also been converted to well pads and associated infrastructure.The single-well and multi-well pad footprints in this study were higher than the industrial estimates. The overall average well pad footprint is 6.45 acres while the average single-well pad and multi-well pad footprint is 5.26 acres and 8.60 acres, respectively. Eighty two percent of well pads had 1-2 wells sited on them. The findings show that the well pad footprint differed based on whether the well pad was located in a core or periphery county, on rangeland or cropland, and that single-well well pad footprint increased over time. Several issues that require further research are outlined.

植被群落特征对城市生态系统服务的影响研究进展

生态空间（林地、灌木、草地、水体）所产生的生态系统服务极大的改善了人类的生存环境，在城市绿地破碎化日益严重、绿地质量逐渐降低、乡土植物逐渐减少、入侵风险逐渐加剧等生态背景下，如何维持稳定而持续增长的城市生态系统服务供给，一直困扰着当下从事城市生态学领域研究的学者和城市管理者。植被群落作为城市绿地系统的基本组成单元，在绿地破碎化趋势下，可作为研究内容来探讨城市生态系统服务维持或提升策略；植被群落泛指城市中常见的、具有明显边界的、按照一定分布规则的植物群落单元，既包括道路绿地、居住区绿地、公园绿地等，也包括城市郊野自然林地。但对植被群落生态功能的研究也多停留在对某一生态问题的简单相关性研究，缺乏系统性和整体性。从微观层面的植被群落角度，整合相关文献研究，介绍了受植被群落特征影响的6种典型城市生态系统服务，综述了植被群落特征对这6种城市生态系统服务的影响机理，对植被群落特征因子进行总结、归类，从树种特性、垂直结构、水平结构、其他4个角度构建了"植被群落特征因子对城市生态系统服务影响关系表"。最后面向典型生态系统服务提升提出了城市低质量植被群落地区的营建和更新原则，以期为今后城市园林部门、规划部门制定城市绿地系统规划提供基础性技术支撑。;The ecosystem services generated by ecological spaces (woodlands, shrubs, grasslands, and water bodies) have greatly improved the human living environment. In the context of increasing fragmentation of urban green spaces, decreasing quality of green spaces, diminishing native plants and increasing risk of invasion, how to maintain a stable and sustainable increase in the supply of urban ecosystem services has been troubling scholars and urban managers. As a basic component of urban green space systems, vegetation communities can be used as a research component to explore strategies for maintaining or enhancing urban ecosystem services in the context of green space fragmentation; vegetation communities refer to common urban plant community units with distinct boundaries and according to certain distribution rules, including both road green space, residential green space and park green space, as well as natural woodland in the urban countryside. while studies on the ecological functions of vegetation communities were mostly confined to simple correlation studies of a certain ecological problem, lacking in a systematic and holistic approach. This paper introduces six typical urban ecosystem services that are influenced by vegetation community characteristics from the perspective of urban vegetation communities at the micro level, integrating relevant literature studies. This is followed by an overview of the mechanisms by which vegetation community characteristics affect these six urban ecosystem services, and a summary and categorisation of vegetation community characteristics factors. A table of relationships between vegetation community characteristics and urban ecosystem services was then constructed from four perspectives:tree species characteristics, vertical structure, horizontal structure and others. Finally, the principles for the establishment and renewal of urban low-quality vegetation communities are proposed for the enhancement of typical ecosystem services, with the aim of providing basic technical support for urban landscape departments and planning departments in their future planning of urban green space systems.

Glenconkeyne: How Ireland’s Largest Native Woodland Became the Timber Yard of the Plantation of Ulster

Glenconkeyne: How Ireland’s Largest Native Woodland Became the Timber Yard of the Plantation of Ulster Gordon D’Arcy (bio) this essay explores the circumstances, particularly the ecological and cultural impacts, resulting from the disappearance of the forest of Glenconkeyne (Figure 1) in central Ulster in the early seventeenth century.1 Research has shown that this exploitation, occurring during the turbulent transition from the Gaelic to the colonial regimes and serving to satisfy the demands of the English “undertakers,” completely eradicated the forest by the mid-seventeenth century. The disappearance of a great forest is much more than the loss of a dramatic landscape feature or of the economic value of its constituent trees as a self-sustaining capital resource and the promise of prosperity. Greater than the sum of its parts: evaluation of the forest’s loss must also consider its vital life-supporting capacity and its hidden layers of human history. Ecologically, forests act as protectorates for flora and fauna, many of which are now endangered or relegated to isolated reserves. Forest biodiversity, especially that of the rain forests, is among the richest known, supporting many species that have unbroken links to primordial beginnings. Forests are thus irreplaceable repositories of living things. Their importance as “super lungs” on which all organisms, including humans, depend is common knowledge and one of the primary motivations for contemporary forest conservation. The removal of a forest also represents radical visual transformation: a [End Page 89] Click for larger view View full resolution Figure 1. Glenconkeyne Woodland, c. 1600 [End Page 90] landscape replete with natural form and texture replaced usually by unadorned modification; a tract of wilderness tamed. Culturally a forest constitutes a discrete arboreal archive. Human history, benign and nefarious, is frequently linked to the “wildwood”: a place of mystery, a place of retreat, a refuge for seekers of inspiration and outlaws—animal and human. Unchronicled narratives, in story and song, in place-names and folklore may survive in tantalizing snippets. However, since most of this archive disappears with the forest, a combination of myth and mystery is the common legacy. In the case of Glenconkeyne sufficient factual reportage survives, though scattered through medieval and early modern documents, to elucidate its former grandeur—and what became of it.2 Analysis of tree pollen from cores and the science of dendrochronology tell us that early forest history in Ireland is much like elsewhere in temperate regions. The process of landnam—clearing trees by “ring-barking” for agriculture, then moving on when the growing potential of the soil is exhausted—affected the Irish landscape from as early as six thousand years ago. The evidence is vividly exposed at Céide Fields in County Mayo, where a system of small fields, created by the first farmers, lies beneath a blanket of bog containing pine stumps, some cleared by ax and fire.3 Though fragmentary and peripheral, landnam was the beginning of a process that reflects Ireland’s uninterrupted preoccupation with the pastoral way of life. Although prolonged episodes of population collapse and natural climate change allowed the forest to return, the steady growth of an essentially rural population resulted in the “opening up” of the country by the end of the Bronze Age, some 2,500 years ago. Some upland regions, formerly afforested, were by this time rendered exposed and treeless by overgrazing: the Burren in County Clare, for instance.4 A climatic change resulting in cooler, wetter conditions subsequently thwarted farming and resulted in widespread forest reinvasion.5 The capacity to manufacture robust agricultural equipment from iron during the Celtic period and the establishment of thousands of ringfort homesteads pushed back the tree cover once again.6 Nevertheless, by the early medieval [End Page 91] period large tracts of primary and secondary forest remained, surrounding uplands, in river valleys, and in the largely inaccessible bogs.7 Abundant Old and Middle Irish references make clear that Gaelic culture included an arboreal sensitivity.8 The early Ogham alphabet, shown to be connected to tree names, may also have been an educational device. The Gaelic brehon law of neighborhood (Bretha Comaithchesa) ranks society in accordance with the usefulness and other attributes of trees.9 While a...

The effects of long-term fertilizations on soil hydraulic properties vary with scales

Soil structure is an indicator of soil quality and its alterations following cropping system conversion or fertilization change evolve slowly. How such alterations vary with scale remains elusive. We investigated this based on the Rothamsted long-term wheat experiment (since 1843) in the UK. Triplicate cores 7 cm high and 10 cm in diameter were taken from plots that have been under different fertilizations or returned to natural woodland for more than one century for imaging using X-ray computed tomography with the voxel size being 40 µm. We then broke each core and sampled three aggregates from it to scan with the voxel size being 1.5 µm. For each core and aggregate sample, we calculated its pore size distribution, permeability and tortuosity. The results showed that the fertilization change >170 years ago reshaped the soil structure differently between the core scale and the aggregate scale. Macro-porosity of the pores (>40 µm) in the cores unfertilized or fertilized with inorganic fertilizers was low and the pores were poorly connected in the top 10 cm of soil, compared to those given farmyard manure or in the woodland. In all treatments, the pores in the core images were hydraulically anisotropic with their permeability in the horizontal direction being higher than that in the vertical direction, whereas the aggregates were comparatively isotropic. The fertilization affected image porosity and permeability at core scale more significantly than at aggregate scale, and the aggregates fertilized with farmyard manure and in the woodland were more permeable than the aggregates in other treatments. It was also found that compared to no-fertilization or fertilization with complete fertilizers, fertilizing without phosphorus over the past 20 years increased the porosity and permeability of the aggregates but not of the cores. Fertilization with inorganic fertilizers increased the tortuosity of the macropores in the cores but not of the intra-aggregate pores, compared to no-fertilization. Porosity-permeability relationship for aggregates unfertilized or fertilized with inorganic fertilisers followed a power law with R2 > 0.8. In contrast, the permeability of the aggregates in farmyard manure and in the woodland trended differently as their porosity increased. The results also revealed that the transport ability of the aggregates and cores responded differently to carbon in that with soil carbon increasing, the permeability of the aggregates increased asymptotically while the permeability of the cores, especially its horizontal component, increased exponentially.

Raising the profile of woodfuels in the forest landscape restoration agenda

AbstractForest landscape restoration (FLR) is being promoted as a means of tackling global challenges including land degradation, climate change, biodiversity conservation and sustainable development. However, as the FLR agenda gains momentum, it is critical that FLR initiatives pay sufficient attention in promoting the sustainable management of woodfuels, so far overlooked. In many regions, woodfuels (firewood and charcoal) are the main energy source for households and play a pivotal role in local economies; yet they are also associated with environmental degradation and adverse health outcomes. Here we examine the reasons why it is important to raise the profile of woodfuels within the FLR agenda and highlight the enabling conditions needed to promote sustainable management of woodfuels. In landscapes where woodfuel use is prevalent, FLR initiatives should consider enhancing wood fuel supply by growing trees, promoting fuel‐efficient cookstoves and kilns, and shifting pressure from natural forests and woodlands to planted trees. We argue that if wood fuel issues are considered in the design, implementation and monitoring of FLR initiatives and are supported by appropriate policies, resources and technical capacity, this will greatly enhance the sustainability and success of FLR initiatives.

Evidence for natural resistance in Juniperus communis to Phytophthora austrocedri

Phytophthora austrocedri is a recently invasive pathogen causing widespread mortality of the ecologically important native conifer, Juniperus communis, in northern Britain. Observations of disease symptoms at severely infected woodlands revealed the presence of individual, apparently healthy trees in areas of high mortality. This study was undertaken to test the hypothesis that these ‘survivor’ trees have greater resistance to P. austrocedri. Rooted cuttings were obtained from seventeen putatively resistant J. communis clones at two heavily infected natural woodlands. Inoculation of excised stems from three putatively resistant clones with P. austrocedri provided initial data to support the hypothesis of resistance. A larger trial was conducted in which whole J. communis plants representing seventeen putatively resistant clones and a known susceptible clone were inoculated with two isolates of P. austrocedri. This trial revealed variation in resistance, with at least six clones exhibiting a high degree of resistance to the pathogen. One surprising finding given the lack of genetic diversity in UK P. austrocedri isolates was that one of the clones was resistant to one isolate and susceptible to the other, warranting further investigation. The next steps are to ascertain whether this natural resistance in J. communis is heritable and exploitable for population recovery.

Informed conservation management of rare tree species needs knowledge of species composition, their genetic characteristics and ecological niche

Woodland nature reserves must be scientifically assessed so that subsequent management leads to optimal conservation of biodiversity. This entails knowledge of the species composition, the genetics of the local populations and their ecology. Here we assess Tilia species in the Bavarian Forest National Park (BFNP), a large mixed coniferous and deciduous forest in South-Eastern Germany. Tilia occurs here at low density, as in many other mixed forests in Central and Northern Europe. Therefore, results are not only relevant to BFNP but also to other areas.Exhaustive sampling resulted in the collection of 113 mature trees that were genotyped using 20 microsatellite markers, derived from both T. cordata and T. platyphyllos. For the first time, size and aspect of trees, and their community association were contrasted between the species. Genotyping confirmed that T. platyphyllos, T. cordata and their hybrid (T. x europaea) were present in the BFNP and both species deserve conservation. T. platyphyllos has a higher genetic diversity for both sets of markers than T. cordata, confirming earlier work. Both species showed genetic diversity comparable to other populations in Central Europe, which is likely to be sufficient for the maintenance of the species in the short term. However, increasing the number of trees, ensuring local sources are used, and gene flow from surrounding forests over the next decennia may be crucial for long-term survival.Further, within the T. platyphyllos group there was a set of 11 trees that were distinct from the others: they had a lower genetic diversity and were shorter. We hypothesise that these were planted and should not be used for propagation and augmentation. Most saplings analysed appeared to derive from asexual propagation (36 out of 41), although a few (five out of 41) were novel genotypes. This means that, currently, there is some, but rather limited, regeneration.T. cordata was found at a lower altitude and less steep terrain than T. platyphyllos and the hybrid. The hybrid was taller than the two species, while the diameter at breast height was smallest in T. cordata. T. cordata shows a preference for mixed and coniferous forests, while T. platyphyllos occurs mostly in deciduous forests.Our results indicate that biodiversity at the species and genetic level as well as species’ ecology have to be considered in order to guide informed conservation management. These results form the basis to recommend conservation management improving the long-term viability of Tilia in the BFNP and other mixed forests.