The remnant mangroves of Sei Kecil,Simpang Hilir,West Kalimantan,Indonesia

Phytosociological analysis of the remnant mangrove forest was carried out in Sei Kecil, Telok Melano, West Kalimantan, to describe the forest composition and structure, and to assess the regeneration strategy of the important mangrove species. Six transect plots of 20 × 60 m, 20 × 80 m and 20 × 90 m, with a total area of one hectare were established perpendicular to the coast line.A total of 20 species of trees and saplings, two species of herbs and one species of nypa palm was recorded. Three community types were recognized namely Rhizophora apiculata, Excoecaria agallocha-Rhizophora apiculata and Excoecaria agallocha reflecting the zonation in this forest.The number of trees, saplings and seedlings were 510, 1220 and 11 085 per ha respectively. Rhizophora apiculata was most successful in regeneration with 6231 seedlings per ha (56.2%) and followed by Bruguiera parviflora with 3810 seedlings per ha (34.4%). Seedlings of the first species were mostly growing under gaps while the second species occurred mostly around the mother trees.     

Scattered trees: a complementary strategy for facilitating adaptive responses to climate change in modified landscapes?

1.  Facilitating adaptive responses of organisms in modified landscape will be essential to overcome the negative effects of climate change and its interaction with land use change. Without such action, many organisms will be prevented from achieving the predicted range shifts they need to survive.
2.  Scattered trees are a prominent feature of many modified landscapes, and could play an important role in facilitating climate change adaptation. They are keystone structures because of the disproportionally large ecological values and ecosystem services that they provide relative to the area they occupy in these landscapes. The provision of habitat and connectivity will be particularly relevant.
3.  Scattered trees are declining in modified landscapes due to elevated tree mortality and poor recruitment often associated with intensive land use. The continuing global decline of scattered trees will undermine the capacity of many organisms to adapt to climate change.
4.   Synthesis and applications. The sustainable management of scattered trees in modified landscapes could complement other strategies for facilitating climate change adaptation. They create continuous, though sparse, vegetation cover that permits multi-directional movements of biota across landscapes and ecological networks. They have the capacity to span ecosystems and climatic gradients that cannot be captured in formal reserves alone. The management of scattered trees should be an integral part of conservation objectives and agricultural activities in modified landscapes. Public investment, through mechanisms such as agri-environmental schemes, in rotational grazing, temporary set-asides, tree-planting and regulations that reduce clearing and early mortality among standing trees will improve the capacity of biota to adapt to climate change.     

强度干扰后退化森林生态系统中保留木的生态效应研究综述

保留木是指森林生态系统受到强度干扰后所存留的树木,保留木对退化森林生态系统结构与功能的维持和恢复具有多方面的生态效应。在生态系统的尺度上总结了退化森林生态系统中保留木的各种生态效应,主要包括保留木对非生物因子和生物因子(附生生物多样性、动物活动和动物多样性、树木更新、空间结构)的影响。森林生态系统经营中,"绿树保留"的经营方式是基于保留木生态效益的实践应用,它可有效减少采伐对生态系统结构和功能所造成的损失。并将有助于深入理解受到强度干扰后森林生态系统中保留木的多种生态效应,可为退化森林生态系统的恢复与重建提供理论依据。     

佛山地区存留自然林和存留人工林的土壤无机磷组分

为探讨热带亚热带森林,尤其城市及其周边地区残存森林土壤磷的有效性,对佛山地区14个残存林(7个自然林和7个人工林)的0~3 cm和3~23 cm矿质土壤的P有效性进行研究。结果表明,铁结合态无机P和还原剂可溶解无机P是土壤无机P的主要组分。在0~3 cm矿质层中,自然林土壤铝结合态无机P、Bray 1提取无机P和总无机P含量显著高于人工林;而在3~23 cm矿质土层中,自然林土壤钙结合态无机P含量显著高于人工林。其它土壤营养指标在自然林和人工林间差异不显著。相关分析结果表明,土壤有机质含量与钙结合态无机P除外的其它无机P组分含量均成显著正相关。聚类分析结果表明14个残存林土壤P有效性可分成3组,整体上人工林土壤P有效性比自然林低。这有助于认识城市化影响下城市及其周边地区残存森林土壤营养状况及加强养分管理。     

Establishment and Growth of Living Fence Species: An Overlooked Tool for the Restoration of Degraded Areas in the Tropics

Numerous tree species can establish by vegetative means in the tropics. Many are used in agriculture as living fences and in alley cropping and could also be used in a restorational setting. However, little is known about their establishment ability. This study evaluated the establishment ability and cover development of multiple species in three separate field trials in northern Honduras. First, 11 species were evaluated for their ability to establish in a common garden experiment. Second, of the former species, Bursera simaruba and Gliricidia sepium were evaluated for 2 years for their ability to establish vegetatively and develop cover at three deforested sites. Lastly, a study examined whether greater initial stake height and diameter at breast height increased the establishment success and crown development of G. sepium stakes. First, five species, Erythrina berteroana, Erythrina fusca, Jatropha curcas, G. sepium, and B. simaruba, had high establishment success. Others showed promise but may have been planted in the wrong season. Second, establishment for G. sepium was nearly 100% at all sites, whereas B. simaruba ranged from 30–50%. Gliricidia sepium stakes developed more rapidly and attained greater cover than B. simaruba. Dry season planting may increase the establishment success of both species. Lastly, greater initial stake height and diameter at breast height each resulted in greater crown development for G. sepium. The use of living fence species as a restorational tool has been overlooked. Aside from the advantages of planting tree species vegetatively, species can act as seed recruitment foci by attracting seed dispersers and provide shade to improve microclimatic conditions for seedling establishment. The technique described is simple and could have broad application throughout tropical regions.     

Soil phosphorus availability determines the contribution of small,individual grassland remnants to the conservation of landscape-scale biodiversity

Questions

Small, remnant habitats embedded in degraded, human-dominated landscapes are generally not a priority in conservation, despite their potential role in supporting landscape-scale biodiversity. To warrant their inclusion in conservation management and policy, we question under which conditions they may exhibit the largest conservation value.

Location

Nine landscapes spread across the counties of Stockholm and Södermanland, Sweden.

Methods

Per landscape, plant communities were surveyed in 6 and 12 1 × 1 m² plots across large, intact semi-natural grasslands and small remnant grasslands, respectively. These two contrasting grassland types served as a model system. A topsoil sample was taken in each plot to determine habitat quality in terms of soil pH, plant-available P, and C:N ratio. We used a joint species distribution model to analyse the extent to which grassland type and habitat quality define and predict resident community diversity and composition, including whether they support grassland specialists.

Results

At the landscape scale, the combined remnant grasslands sustained diverse plant communities which did include a significant subset of habitat specialists. Yet, the contribution of individual remnants clearly varied with local-scale habitat quality; soil phosphorus availability lowered plot-level species richness, mostly by constraining the occurrence of grassland specialists. Semi-natural grassland communities were comparatively insensitive to variation in soil phosphorus availability.

Conclusions

The combined habitat amount and the significant number of habitat specialists sustained by remnant grasslands with high habitat quality, shows they can represent a valuable resource to support landscape-scale biodiversity conservation. This offers no wildcard to neglect the continued biotic and abiotic threats on semi-natural grassland plant diversity such as chronic and accumulating P eutrophication, discontinuation of management or poor matrix permeability, as semi-natural grasslands harbour the majority of habitat specialists, while sourcing surrounding remnant grassland communities.

     

Measures of postprandial lipoproteins are not associated with coronary artery disease in patients with type 2 diabetes mellitus

Individuals with type 2 diabetes mellitus (DM) characteristically have elevated fasting and postprandial (PP) plasma triglycerides (TG). Previous case-control studies indicated that PPTG levels predict the presence of coronary artery disease (CAD) in people without DM; however, the data for patients with DM are conflicting. Therefore, we conducted a case-control study in DM individuals, 84 with (+) and 80 without (−) CAD. Our hypothesis was that DM individuals with or without CAD would have similar PPTG levels, but CAD+ individuals would have more small d<1.006 g/L lipoprotein particles. Several markers of PP lipid metabolism were measured over 10 h after a fat load. PP lipoprotein size and particle number were also determined. There was no significant difference in any measure of PP lipid metabolism between CAD+ and CAD−, except for apoB48, which was actually higher in CAD−. We followed 69 CAD− participants for a mean 8.7 years; 33 remained free of any cardiovascular event. There were no PP differences at baseline between these 33 who remained CAD− and either the 36 original CAD− who subsequently developed CAD or the original CAD+ group.PP measurements of TG-rich lipoproteins do not predict the presence of CAD in individuals with DM.     

Comparison of genetic variability in remnant and wide-spread rainforest understorey species of Austromyrtus (Myrtaceae)

This study investigated the genetic variability, stand structure, and reproductive activity of four species of Austromyrtus which showed differing levels of rarity and patterns of distribution. The focus of the study was A. gonoclada which is extremely rare due to extensive urban expansion in Brisbane, Australia. The total number of known individuals in the species is only 27. Because nothing was known about the genetic structure of Austromyrtus comparison with other species was made to provide a context for studies on A. gonoclada. Population structure and levels of reproductive activity were not correlated to species rarity or distribution. A. gonoclada showed maximum genetic variability in comparison to the other species of Austromyrtus, despite the small population size. Three of six variable loci were in Hardy-Weinberg equilibrium in A. gonoclada populations, in contrast to populations of the other species which had few heterozygous genotypes. The higher variability of the remaining individuals is suggested to be a legacy of the relatively short time since they were part of a larger population. There were very few seedlings of A. gonoclada, in contrast to the other species of Austromyrtus and the seeds produced fell from the tree while still green and were unable to be germinated. A. gonoclada is under continuing threat from development and has low reproductive success. Active programmes for recovery of this species will be necessary as its continued survival is dependent on population increase. Management of the genetic resources of the species will enable survival with long-term evolutionary potential.     

Australia’s Stock Route Network: 1. A review of its values and implications for future management

Summary The Stock Route Network (SRN) is a vast system of public land, comprising vegetated strips and small reserves across the eastern length of the Australian continent. Now predominantly following the road system, this network was historically established to allow for the movement of livestock prior to truck and railway transport. Owing to declines in traditional uses, parts of the SRN may now be sold to private landholders, or put under long‐term grazing leases, making them unavailable for other emerging uses. This is in spite of the fact that it is widely accepted by researchers, practitioners, graziers and agriculturalists that the SRN holds great natural and cultural value. We conducted a review of scientific and grey literature to determine the known values of the network for biodiversity conservation, cultural heritage, rural communities and Australian society as a whole. We found that the majority of existing literature on the network focuses on New South Wales (NSW) and is of a conservation‐based nature. The Stock Route Network supports a wide range of threatened species and communities, with considerable potential for many more to be discovered. The network also holds heritage value for both Indigenous and non‐Indigenous Australians. The societal benefits from the SRN are numerous because it provides land for recreation and apiary sites, a source of seed for revegetation projects, a focus for rural tourism, as well as the traditional benefits for stock droving and emergency agistment. In the light of our review, we identified key knowledge gaps pertaining to the values of the SRN and propose a number of options for its future management. Appropriate governance and increased investment in SRN management is now urgently required to ensure that it continues to conserve its many environmental and social values in perpetuity.