Rehabilitation of former Snowy Scheme sites in Kosciuszko National Park

Ten years of restoration work at 200 sites within Kosciuszko National Park – sites damaged during the construction of Australia's most iconic hydroelectric scheme – is showing substantial progress and is contributing to the protection of the park's internationally significant ecosystems.     

管道工程迹地土壤修复效果及植物多样性特征

以天然气地下管道工程竣工后的砒砂岩及沙地为研究对象,探讨经4年封育及人工种草恢复后的土壤修复效果及植物多样性特征。结果表明：（1）砒砂岩及沙地土地类型上共有29个植物种,以多年生草本植物为主。封育恢复4年后,砒砂岩及沙地的植物群落均处于进展演替的初级阶段。相比人工种草恢复,封育恢复可更好地增加沙地植物丰富度及多样性。（2）砒砂岩土壤全氮及有机碳含量仅在封育恢复后高于天然草地,而沙地经封育及人工种草恢复方式后,土壤全氮及有机碳含量均高于天然草地。封育及人工种草恢复方式有助于改善管道工程迹地土壤养分状况及提升植物多样性。     

Effects of Initial Site Treatments on Early Growth and Three-Year Survival of Idaho Fescue

Prairies in the Pacific Northwest have been actively restored for over a decade. Competition from non‐native woody and herbaceous species has been presumed to be a major cause for the failure of restoration projects. In this research, plugs of the native prairie bunchgrass, Festuca idahoensis Elmer var. roemeri (Pavlick), were grown from seed in a nursery and transplanted into a grassland site dominated by non‐native pasture grasses. The growth of the plants was followed for three years, and biomass of all volunteer plants was measured. Before planting, five treatments were applied to the plots: removal of vegetation by burning, removal of vegetation by an herbicide‐and‐till procedure, soil impoverishment by removal of organic matter, fertilizer application, and compost mulch application. Initial growth of Idaho fescue plugs was greatest with fertilizer and compost mulch. Plants grown in mulched plots were also able to photosynthesize later into the dry summer season. After the first year, plots initially fertilized or composted had the lowest survival rate of Idaho fescue. Impoverished and herbicide‐and‐till plots had the greatest 3‐year survival. Mulched plots supported the greatest weed growth after three years. Stressful environments give a competitive advantage to Idaho fescue in prairie restoration projects. As weedy species increase, growth and survival of Idaho fescue decreases.     

The interactions of composting and biochar and their implications for soil amendment and pollution remediation: a review

Compost and biochar, used for the remediation of soil, are seen as attractive waste management options for the increasing volume of organic wastes being produced. This paper reviews the interaction of biochar and composting and its implication for soil amendment and pollution remediation. The interaction of biochar and composting affect each other’s properties. Biochar could change the physico-chemical properties, microorganisms, degradation, humification and gas emission of composting, such as the increase of nutrients, cation exchange capacity (CEC), organic matter and microbial activities. The composting could also change the physico-chemical properties and facial functional groups of biochar, such as the improvement of nutrients, CEC, functional groups and organic matter. These changes would potentially improve the efficiency of the biochar and composting for soil amendment and pollution remediation. Based on the above review, this paper also discusses the future research required in this field.     

Ecological restoration of a severely degraded coastal acid sulfate soil: A case study of the East Trinity wetland,Queensland

A severely degraded acid sulfate soil wetland near Cairns, Queensland, has been returned to a functional estuarine habitat using a cost‐effective, low‐technology method based on the reintroduction of tidal water. Gradual increases in tidal inundation, combined with targeted liming of the tidal stream, restored conditions that promoted chemical and microbial processes leading to the rapid recolonisation of mangrove communities and other estuarine flora and fauna. Protocols and understanding developed at East Trinity can be readily applied to other coastal acid sulfate soil sites.     

Soil temperature in a sugar-cane crop as a function of the management system

Air and soil temperatures are, by far, the most important state variables of agroecosystems. In the case of sugar-cane (Saccharum officinarum L.) they affect plant development, maturation and a series of biological and physical-chemical soil processes. This paper presents a comparative study of three management practices, applied to the first ratoon of a sugar-cane crop established on a Rhodic Kandiudox (Terra Roxa Estruturada) of Piracicaba, SP, Brazil. The management practices are: (i) interrow with bare soil; (ii) trash mulching, maintaining harvest residues (straw+tips) on the soil; (iii) soil with residues from burning the prior crop. Soil temperature was measured with digital stick thermometers driven into the soil down to the depths of 0.03, 0.06 and 0.09 m, meter by meter, close to the crop row, along an 84-point transect that covered all treatments and borders. The measurements were performed from November 1998 (right after the first harvest of the planted cane) to June 1999. The effects of the treatments on soil temperature were, evidently, more prominent in the period November/February when the plants had a smaller height, not closing interrows. Data that were collected on typical days, chosen along the development cycle of the crop, always from 11:00 to 12:00 a.m., show significant differences, mainly between mulched and non mulched treatments, reaching values as high as 7 °C for the average of the three depths. A comparative analysis is made between treatments and their effects are discussed in relation to the sugar-cane crop.     

Assessment of Landfill Leachate Volume and Concentrations of Cyanide and Fluoride during Phytoremediation

The potential for plants to minimize leachate volume and reduce cyanide and fluoride concentrations in groundwater was evaluated. High fluoride and soluble salts in the leachate induced chlorosis or necrosis in the leaf margins on green ash (Fraxinus pennsylvanica), yellow poplar (Liriodendron tulipifera), and bald cypress (Taxodium distichum). Hybrid willow (Salix Willow hybrid), sycamore (Platanus sp.), and black willow (Salix nigra) had high rates of transpiration and root growth during the study period. Cyanide in the leachate was removed by plant metabolic processes whereas fluoride accumulated in the leaves. Cyanide and fluoride in landfill leachate can be decreased through phytoremediation.     

Restoring Western (Basalt) Plains grassland. 2. Field emergence, establishment and recruitment following direct seeding

Summary   Both reservation of small remnants and ecological restoration of degraded areas will be crucial if the Victorian Western (Basalt) Plains grassland community is to be conserved in the long term. This study examined the potential of direct seeding as a technique for grassland restoration by recording the initial establishment and subsequent recruitment success of 64 (predominantly perennial) grassland species direct sown onto a constructed site. Forty-three (67%) of the sown species emerged and established during the 2-year study and a further three species were recorded in subsequent years. In the second year, 32 species increased their number either through seedling or vegetative recruitment and 30 species dispersed beyond their original sown plot. Seed size was not correlated with field emergence but life form did influence initial field success for some groups. The finding that many species are able to establish and recruit under the study conditions supports the need for further investigation of direct seeding in the restoration of grassland communities.     

Can current native tree seedling production and infrastructure meet an increasing forest restoration demand in Brazil?

Recent global commitments have placed forest and landscape restoration at the forefront of countries' efforts to recover ecosystem services, conserve biodiversity, and mitigate the effects of climate change. However, it needs to be asked if current native tree seedling supply meets an increase in demand for forest restoration? This study assessed the current configuration, distribution, and production capacity of forest nurseries producing native trees in Brazil. Brazil provides an interesting example of how global agreements aligned with national policies can lead to the proliferation of native seedling nurseries, and the challenges faced to restore species‐rich native forest ecosystems. We found that the nurseries in the Atlantic Forest region can still meet an increase in demand—both in terms of seedling quantity and diversity—because most of their production capacity is not currently used. However, not all Brazilian biomes have sufficient nurseries to meet restoration demands, thus there is a risk of using native species from a few biogeographical regions in a much spatially wider and ecologically diverse area. In addition, lack of seed supply and qualified labor can hamper the growth of the market. Barriers to seed supply may also lead to low levels of genetic variability and floristic representation in the populations and ecosystems to be restored. We conclude that restoration of high‐diversity forest ecosystems requires policies and supportive programs, with emphasis on private nurseries, to guarantee adequate supply of native tree seedlings and provide the necessary incentives to develop the emergent economy of forest restoration.     

Development and Placement of a Sorbent-Amended Thin Layer Sediment Cap in the Anacostia River

Incorporating materials into sediment caps that can sequester contaminants will greatly improve their ability to isolate contaminants in the underlying sediments from the rest of the aquatic environment. For highly sorptive media a thin layer (cm) may be sufficient, but accurately placing a thin layer (cm) of material over submerged contaminated sediment is difficult. A reactive core mat (RCM) was designed to accurately place a 1.25 cm thick sorbent (coke) layer in an engineered sediment cap. In April 2004, twelve 3.1 m × 31 m sections of RCM were placed in the Anacostia River, Washington, D.C., and overlain with a 15 cm layer of sand to secure it and provide a habitat for benthic organisms to colonize without compromising the integrity of the cap. Placement of the RCM did not cause significant sediment re-suspension or impact site hydrology. The RCM is an inexpensive and effective method to accurately deliver thin layers of difficult to place, high value, sorptive media into sediment caps. The approach can also be used to place granular reactive media that can degrade or mineralize contaminants.