The effects of habitat fragmentation due to forestry plantation establishment on the demography and genetic variation of a marsupial carnivore, Antechinus agilis

We conducted a demographic and genetic study to investigate the effects of fragmentation due to the establishment of an exotic softwood plantation on populations of a small marsupial carnivore, the agile antechinus (Antechinus agilis), and the factors influencing the persistence of those populations in the fragmented habitat. The first aspect of the study was a descriptive analysis of patch occupancy and population size, in which we found a patch occupancy rate of 70% among 23 sites in the fragmented habitat compared to 100% among 48 sites with the same habitat characteristics in unfragmented habitat. Mark-recapture analyses yielded most-likely population size estimates of between 3 and 85 among the 16 occupied patches in the fragmented habitat. Hierarchical partitioning and model selection were used to identify geographic and habitat-related characteristics that influence patch occupancy and population size. Patch occupancy was primarily influenced by geographic isolation and habitat quality (vegetation basal area). The variance in population size among occupied sites was influenced primarily by forest type (dominant Eucalyptus species) and, to a lesser extent, by patch area and topographic context (gully sites had larger populations). A comparison of the sex ratios between the samples from the two habitat contexts revealed a significant deficiency of males in the fragmented habitat. We hypothesise that this is due to male-biased dispersal in an environment with increased dispersal-associated mortality. The population size and sex ratio data were incorporated into a simulation study to estimate the proportion of genetic diversity that would have been lost over the known timescale since fragmentation if the patch populations had been totally isolated. The observed difference in genetic diversity (gene diversity and allelic richness at microsatellite and mitochondrial markers) between 16 fragmented and 12 unfragmented sites was extremely low and inconsistent with the isolation of the patch populations. Our results show that although the remnant habitat patches comprise approximately 2% of the study area, they can support non-isolated populations. However, the distribution of agile antechinus populations in the fragmented system is dependent on habitat quality and patch connectivity. (C) 2004 Elsevier Ltd. All rights reserved.

Financial and economic performance of long-rotation hardwood plantation investments in Queensland, Australia

In Queensland, Australia, there is presently a high level of interest in long-rotation hardwood plantation investments for sawlog production, despite the consensus in Australian literature that such investments are not financially viable. Continuing genetics, silviculture and processing research, and increasing awareness about the ecosystem services generated by plantations, are anticipated to make future plantings profitable and socio-economically desirable in many parts of Queensland. Financial and economic models of hardwood plantations in Queensland are developed to test this hypothesis. The economic model accounts for carbon sequestration, salinity amelioration and other ecosystem service values of hardwood plantations. A carbon model estimates the value of carbon sequestered, while salinity and other ecosystem service values are estimated by the benefit transfer method. Where high growth rates (20-25 m(3) ha(-1) year(-1)) are achievable, long-rotation hardwood plantations are profitable in Queensland Hardwood Regions 1, 3 and 7 when rural land values are less than $2300/ha. Under optimistic assumptions, hardwood plantations growing at a rate of 15 in 3 ha-1 year 1 are financially viable in Hardwood Regions 2, 4 and 8, provided land values are less than $1600/ha. The major implication of the economic analysis is that long-rotation hardwood plantation forestry is socio-economically justified in most Hardwood Regions, even though financial returns from timber production may be negative. (c) 2003 Elsevier B.V. All rights reserved.

Planted forests and biodiversity

Expansion of planted forests and intensification of their management has raised concerns among forest managers and the public over the implications of these trends for sustainable production and conservation of forest biological diversity. We review the current state of knowledge on the impacts of plantation forestry on genetic and species diversity at different spatial scales and discuss the economic and ecological implications of biodiversity management within plantation stands and landscapes. Managing plantations to produce goods such as timber while also enhancing ecological services such as biodiversity involves tradeoffs, which can be made only with a clear understanding of the ecological context of plantations in the broader landscape and agreement among stakeholders on the desired balance of goods and ecological services from plantations.

The men behind the market: Merchants, the Atlantic slave trade, and the shaping of South Carolina plantation society, 1700–1756

The purpose of this dissertation is to examine the role played by merchants in the shaping of South Carolina plantation society in its early stages of development. In 1700 South Carolina was on the fringes of the British Empire. By mid-century the colony had become an integral part of the British Atlantic system. This dissertation addresses merchants' activity in the shaping of plantation society through their involvement in the Atlantic slave trade. Records of the British and South Carolina governments, and petitions from merchants on both sides of the Atlantic have been extremely valuable in understanding the complex and rapidly changing political affiliations of merchants on both sides of the Atlantic. These sources are valuable to this study since they illustrate the merchants' strategy of utilizing government policies to acquire the absolute best terms of trade. Records such as wills and inventories yielded valuable information on merchants' economic portfolios and provided valuable insight into their personal lives. The data shows that the integration of Colonial South Carolina into the global economy can be attributed to its merchant class, who actively sought out business opportunities in the global economy while working within the framework of British mercantilism.

Effect of Cocoa ( Theobroma cacao ) Plantation Types on the Distribution of Anuran Communities in Ore, Ondo State, Nigeria

Anuran species diversity and abundance were evaluated in different farming status of cocoa plantation in Ore, Ondo State, Nigeria. Applying the combination of visual encounter survey (VES) and acoustical survey (AES), the different farms surveyed were categorized as; 1) pure cocoa farms with pesticides applied (PCWP); 2) pure cocoa farms without pesticides application; 3) intercropped cocoa farms with pesticides applied (ICWP); and 4) intercropped cocoa farms without pesticides application (ICNP). The surrounding primary/secondary forest (PSFV) was sampled applying the transect method. A mean total of 690±2.6 anurans belonging to 28 species, 14 genera and 9 families were recorded during the study. Out of these, 10, 19, 17, 22 and 26 species were recorded respectively from PCWP, PCNP, ICWP, ICNP and PSFV. The anuran species richness was significantly different between the different cocoa plantation status and the forest sites (F4, 10 = 20.55, P< 0.01). The highest mean number of individuals (190±9.5) was observed at ICNP followed by PSFV (183±5.7), while the least was at PCWP (77±8.0). There was also significant difference (F4, 10 = 150.48, P< 0.01) between the abundance of anuran species at the various sites. Diversity indices (Shannon and Margalef) showed that the forest sites had the greatest (3.204 and 4.799) respectively while the pesticide using pure cocoa farms had the least (1.853 and 2.072). Generally, the result of the study clearly indicated that pesticide use cocoa farms were significantly lower compared to other sites. Farmers are encouraged to engage in intercropping (polyculture) especially with food and economic crops in a biodiversity friendly manner which could have similar characteristics of a natural ecosystem, thereby enhancing the biological diversity of agro-ecosystems.

Conservation of tropical forest tree species in a native timber plantation landscape

Tropical terrestrial environments are becoming dominated by anthropogenic land-uses, making retention of biodiversity in production landscapes of critical conservation importance. Native timber plantations may represent a land-use capable of balancing production and conservation by potentially supporting understorey plant and tree species otherwise restricted to old-growth forests, with little impact on yield. In this study we investigated the conservation value of native plantation forests in the lowlands of New Britain, Papua New Guinea. We compared the composition of tree species (≥10. cm DBH) of unlogged forest to those of different aged native Eucalyptus deglupta plantations and intervening (historically logged) secondary forests. We found a high capacity for biodiversity conservation within plantations, with 70% of forest tree species persisting in mature plantations (13-15. years old). However, compositional analyses revealed lower numbers of large individuals (≥10. cm DBH) in both late-successional and non-vertebrate-dispersed species in the plantations, indicating the difficulty of retaining mature old-growth forest trees in production land-uses. Secondary forest protected by conservation reserves was compositionally indistinct to unlogged forest. Our results demonstrate the potential for tropical native timber plantations to contribute to the retention of biodiversity. However, appropriate management is required to ensure the persistence of source populations of old-growth forest tree species. With careful planning a balance between production and conservation can be achieved in lowland tropical regions.

Diversity of root-associated arbuscular mycorrhizal fungal communities in a rubber tree plantation chronosequence in Northeast Thailand

Rubber tree (Hevea brasiliensis) is of major economic importance in Southeast Asia and for small land holders in Thailand in particular. Due to the high value of latex, plantations are expanding into unsuitable areas, such as the northeast province of Thailand where soil fertility is very low and therefore appropriate management practices are of primary importance. Arbuscular mycorrhizal fungi (AMF) contribute to plant growth through a range of mechanisms and could play a key role in a more sustainable management of the rubber plantations. We described the diversity of AMF associated with rubber tree roots in Northeast Thailand in relation to tree age and soil parameters along a chronosequence of rubber tree plantations. Cassava fields were included for comparison. Rubber tree and cassava roots harbored high diversity of AMF (111 Virtual Taxa, VT), including 20 novel VT. AMF VT richness per sample was consistently high (per site mean 16 to 21 VT per sample) along the chronosequence and was not related to soil properties. The composition of AMF communities differed between cassava and rubber tree plantations and was influenced by soil texture and nutrient content (sand, K, P, Ca). AMF community composition gradually shifted with the age of the trees. Our results suggest that the high diversity of AMF in this region is potentially significant for maintaining high functionality of AMF communities.

The use of traits to interpret responses to large scale - edge effects: a study of epigaeic beetle assemblages across a Eucalyptus forest and pine plantation edge

Context: Edge effects due to habitat loss and fragmentation have pervasive impacts on many natural ecosystems worldwide. Objective: We aimed to explore whether, in tandem with the resource-based model of edge effects, species feeding-guild and flight-capacity can help explain species responses to an edge. Methods: We used a two-sided edge gradient that extended from 1000 m into native Eucalyptus forest to 316 m into an exotic pine plantation. We used generalised additive models to examine the continuous responses of beetle species, feeding-guild species richness and flight-capable group species richness to the edge gradient and environmental covariates. Results: Phytophagous species richness was directly related to variation in vegetation along the edge gradient. There were more flight-capable species in Eucalyptus forest and more flightless species in exotic pine plantation. Many individual species exhibited multiple-peaked edge-profiles. Conclusions: The resource based model for edge effects can be used in tandem with traits such as feeding-guild and flight-capacity to understand drivers of large scale edge responses. Some trait-groups can show generalisable responses that can be linked with drivers such as vegetation richness and habitat structure. Many trait-group responses, however, are less generalisable and not explained by easily measured habitat variables. Difficulties in linking traits with resources along the edge could be due to unmeasured variation and indirect effects. Some species’ responses reached the limits of the edge gradient demonstrating the need to examine edge effects at large scales, such as kilometres.

Biological nitrogen fixation and nutrient release from litter of the guachapele leguminous tree under pure and mixed plantation with eucalyptus.

A Pseudosamanea guachapele (guachapele), leguminosa arbórea fixadora de nitrogênio, é uma alternativa para plantios florestais mistos nos trópicos. Como são escassas as informações sobre a espécie em plantios mistos de eucalipto em condições edafoclimáticas brasileiras, foi conduzido um experimento no qual objetivou-se avaliar a contribuição da fixação biológica de nitrogênio para a guachapele e a velocidade de decomposição e de liberação de nutrientes de folhas senescentes de eucalipto e guachapele (oriundas dos plantios puros e consorciado). A porcentagem de N derivado da atmosfera (% Ndfa) foi estimada comparando-se a abundância natural de 15N ( 15N, ) nos tecidos da guachapele com a observada nos tecidos do Eucalyptus grandis, espécie não fixadora, ambas com sete anos de idade. A constante de decomposição (k) e a meia-vida (t1/2) de serapilheira foram estimadas utilizando-se o modelo exponencial aplicado aos dados oriundos de coletas de litterbags. A estimativa da %Ndfa para guachapele, em condições de plantio puro, variou de 17 a 36%, enquanto que, em condições de plantio consorciado, foi de 35 a 60 %. A concentração de N nas folhas senescentes estava positivamente relacionada com a taxa de decomposição, sendo essa decrescente da guachapele para o eucalipto. A t1/2 dos resíduos diferiu significativamente (p < 0.05), sendo de 148, 185 e 218 dias para as folhas de guachapele, mistura das duas espécies e eucalipto, respectivamente. A liberação dos nutrientes (principalmente N, K e Mg) das folhas seguiu a mesma ordem da t1/2 devido à qualidade inicial das mesmas. Os resultados indicam que a guachapele pode beneficiar o plantio misto pela adição de N e por meio da intensificação da decomposição da serapilheira.

Fertilization and cover crop effects on soil nitrogen and plant nutrition in a young guarana plantation.

O presente estudo quantificou os efeitos da fertilização mineral e da cobertura do solo com uma leguminosa (Pueraria phaseoloides (Roxb) Benth.) sobre a dinâmica de nutrientes no sistema solo-planta.

Domestic and export marketing of Auracaria timber

This article examines the need for a marketing approach to support the expansion of trade in Australian forest Products. Opportunities available for trade in hoop pine ( Araucaria cunninghamii), a Queensland species of timber, are examined. Markets within China and Japan are found to have substantial potential end product uses for the plantation timber.

The role of timber plantations in UK Investment portfolios

Although timber plantations and forests are classified as forms of agricultural production, the ownership of this land classification is not limited to rural producers. Timber plantations and forests are now regarded as a long-term investment with both institutional and absentee owners. While the NCREIF property indices have been the benchmarks for the measurement of the performance of the commercial property market in the UK, for many years the IPD timberland index has recently emerged as the U.K. forest and timberland performance indicator. The IPD Forest index incorporates 126 properties over five regions in the U.K. This paper will utilise the IPD Forestry Index to examine the performance of U.K. timber plantations and forests over the period 1981-2004. In particular, issues to be critically assessed include plantation and forest performance analysis, comparative investment analysis, and the role of plantations and forests in investment portfolios, the risk reduction and portfolio benefits of plantations and forests in mixed-asset portfolios and the strategic investment significance of U.K. timberlands.