Post‐fire recovery of revegetated woodland communities in south‐eastern Australia

The primary goal of restoration is to create self‐sustaining ecological communities that are resilient to periodic disturbance. Currently, little is known about how restored communities respond to disturbance events such as fire and how this response compares to remnant vegetation. Following the 2003 fires in south‐eastern Australia we examined the post‐fire response of revegetation plantings and compared this to remnant vegetation. Ten burnt and 10 unburnt (control) sites were assessed for each of three types of vegetation (direct seeding revegetation, revegetation using nursery seedlings (tubestock) and remnant woodland). Sixty sampling sites were surveyed 6 months after fire to quantify the initial survival of mid‐ and overstorey plant species in each type of vegetation. Three and 5 years after fire all sites were resurveyed to assess vegetation structure, species diversity and vigour, as well as indicators of soil function. Overall, revegetation showed high (>60%) post‐fire survival, but this varied among species depending on regeneration strategy (obligate seeder or resprouter). The native ground cover, mid‐ and overstorey in both types of plantings showed rapid recovery of vegetation structure and cover within 3 years of fire. This recovery was similar to the burnt remnant woodlands. Non‐native (exotic) ground cover initially increased after fire, but was no different in burnt and unburnt sites 5 years after fire. Fire had no effect on species richness, but burnt direct seeding sites had reduced species diversity (Simpson's Diversity Index) while diversity was higher in burnt remnant woodlands. Indices of soil function in all types of vegetation had recovered to levels found in unburnt sites 5 years after fire. These results indicate that even young revegetation (stands <10 years old) showed substantial recovery from disturbance by fire. This suggests that revegetation can provide an important basis for restoring woodland communities in the fire‐prone Australian environment.     

Revegetation to combat tree decline in the Midlands and Derwent Valley Lowlands of Tasmania: Practices for improved plant establishment

Summary The results of site assessment and information survey of 13 plantings established between 1995 and 2000 from the Tasmanian Midlands and Derwent Valley Lowlands are presented. Establishment success of tubestock plantings ranged from 2 to 100% and that of direct seeding from 860 to 20 000 seedlings/ha. Successful establishment of tubestock and direct seeding was associated with first year watering and good rains, respectively. Browsing damage was evident in direct seeded plots with eucalypts most affected and acacias and She-oak ( Allocasuarina verticillata ) least affected. Treeguards appeared to prevent browsing of tubestock, but those poorly constructed by inexperienced planters tended to collapse and smother seedlings. Larger seedlings appeared to exhibit better survival and growth than smaller seedlings under conditions of drought. While only two sites were mounded, mounding appeared superior over ripping as a site preparation technique, particularly where ripping on heavy, black cracking clays induces cracking, drying of the soil profile and seedling mortality when planted too close to rip lines. Recommendations are listed for best practice establishment techniques based on the site assessment and survey results. Of the recommendations, the requirement for postplanting weed control and the benefits of detailed records of plantings are emphasized. Most plantings surveyed would have benefited from postplanting weed control and it is suggested that this has been a major deficiency in previous revegetation programs. Furthermore, there has been little accountability of the success of projects undertaken. Improved record keeping would benefit landholders and particularly extension officers and researchers in the industry.     

Fauna community trends during early restoration of alluvial open forest/woodland ecosystems on former agricultural land

Vertebrate fauna was studied over 10 years following revegetation of a Eucalyptus tereticornis ecosystem on former agricultural land. We compared four vegetation types: remnant forest, plantings of a mix of native tree species on cleared land, natural regeneration of partially cleared land after livestock removal, and cleared pasture land with scattered paddock trees managed for livestock production. Pasture differed significantly from remnant in both bird and nonbird fauna. Although 10 years of ecosystem restoration is relatively short term in the restoration process, in this time bird assemblages in plantings and natural regeneration had diverged significantly from pasture, but still differed significantly from remnant. After 10 years, 70 and 66% of the total vertebrate species found in remnant had been recorded in plantings and natural regeneration, respectively. Although the fauna assemblages within plantings and natural regeneration were tracking toward those of remnant, significant differences in fauna between plantings and natural regeneration indicated community development along different restoration pathways. Because natural regeneration contained more mature trees (dbh > 30 cm), native shrub species, and coarse woody debris than plantings from the beginning of the study, these features possibly encouraged different fauna to the revegetation areas from the outset. The ability of plantings and natural regeneration to transition to the remnant state will be governed by a number of factors that were significant in the analyses, including shrub cover, herbaceous biomass, tree hollows, time since fire, and landscape condition. Both active and passive restoration produced significant change from the cleared state in the short term.     

Rehabilitation of Swamp Paperbark (<Emphasis Type="Italic">Melaleuca ericifolia</Emphasis>) wetlands in south-eastern Australia: effects of hydrology,microtopography, plant age and planting technique on the success of community-based revegetation trials

Wetlands dominated by Swamp Paperbarks (Melaleuca spp., Myrtaceae) are common in coastal regions across Australia. Many of these wetlands have been filled in for coastal development or otherwise degraded as a consequence of altered water regimes and increased salinity. Substantial resources, often involving community groups, are now being allocated to revegetating the remaining wetland sites, yet only rarely is the effectiveness of the rehabilitation strategies or on-ground procedures robustly assessed. As part of a larger project investigating the condition and rehabilitation of brackish-water wetlands of the Gippsland Lakes, we overlaid a scientifically informed experimental design on a set of community-based planting trials to test the effects of water depth, microtopography, plant age and planting method on the survival and growth of seedlings of Melaleuca ericifolia Sm. in Dowd Morass, a degraded, Ramsar-listed wetland in south-eastern Australia. Although previous laboratory and greenhouse studies have shown M. ericifolia seedlings to be salt tolerant, the strongly interactive effects of waterlogging and salinity resulted in high seedling mortality (>90%) in the field-based revegetation trials. Seedlings survived best if planted on naturally raised hummocks vegetated with Paspalum distichum L. (Gramineae), but their height was reduced compared with seedlings planted in shallowly flooded environments. Age of plants and depth of water were important factors in the survival and growth of M. ericifolia seedlings, whereas planting method seemed to have little effect on survival. Improved testing of revegetation methods and reporting of success or otherwise of revegetation trials will improve the effectiveness and accountability of projects aiming to rehabilitate degraded coastal wetlands.     

Not all kinds of revegetation are created equal: revegetation type influences bird assemblages in threatened Australian woodland ecosystems

The value for biodiversity of large intact areas of native vegetation is well established. The biodiversity value of regrowth vegetation is also increasingly recognised worldwide. However, there can be different kinds of revegetation that have different origins. Are there differences in the richness and composition of biotic communities in different kinds of revegetation? The answer remains unknown or poorly known in many ecosystems. We examined the conservation value of different kinds of revegetation through a comparative study of birds in 193 sites surveyed over ten years in four growth types located in semi-cleared agricultural areas of south-eastern Australia. These growth types were resprout regrowth, seedling regrowth, plantings, and old growth.Our investigation produced several key findings: (1) Marked differences in the bird assemblages of plantings, resprout regrowth, seedling regrowth, and old growth. (2) Differences in the number of species detected significantly more often in the different growth types; 29 species for plantings, 25 for seedling regrowth, 20 for resprout regrowth, and 15 for old growth. (3) Many bird species of conservation concern were significantly more often recorded in resprout regrowth, seedling regrowth or plantings but no species of conservation concern were recorded most often in old growth. We suggest that differences in bird occurrence among different growth types are likely to be strongly associated with growth-type differences in stand structural complexity.Our findings suggest a range of vegetation growth types are likely to be required in a given farmland area to support the diverse array of bird species that have the potential to occur in Australian temperate woodland ecosystems. Our results also highlight the inherent conservation value of regrowth woodland and suggest that current policies which allow it to be cleared or thinned need to be carefully re-examined.     

Spatially designed revegetation—why the spatial arrangement of plants should be as important to revegetation as they are to natural systems

The spatial arrangements of plants, both within and between species, play a key role in natural systems and influence many fundamental ecological processes (e.g. survival, competition, facilitation, pollination, and seed dispersal) and ecosystem functions (e.g. habitat value, erosion, water, and nutrient capture). Despite this knowledge, fine‐scale planting arrangements are rarely considered during restoration plantings, yet manipulation of planting designs has the potential to aid the development of resilient and self‐sustaining ecosystems. Here, we outline how the spatial arrangement of plants can influence processes both at the vegetation level and more broadly at the ecosystem level. The review is focused on woodland systems, but also draws on key examples from grassland ecosystems. Following this synthesis, we identify research gaps in the revegetation literature that could usefully be addressed to help develop this understudied field of research. Finally, we outline components of population and community level arrangements (e.g. spacing, aggregation, community composition) that can be considered during restoration plantings—spatially designed revegetation—which are likely to lead to improved ecological outcomes of woodland and grassy woodland revegetation.     

Forecasting trait responses in novel environments to aid seed provenancing under climate change

Revegetation projects face the major challenge of sourcing optimal plant material. This is often done with limited information about plant performance and increasingly requires factoring resilience to climate change. Functional traits can be used as quantitative indices of plant performance and guide seed provenancing, but trait values expected under novel conditions are often unknown. To support climate-resilient provenancing efforts, we develop a trait prediction model that integrates the effect of genetic variation with fine-scale temperature variation. We train our model on multiple field plantings of Arabidopsis thaliana and predict two relevant fitness traits—days-to-bolting and fecundity—across the species' European range. Prediction accuracy was high for days-to-bolting and moderate for fecundity, with the majority of trait variation explained by temperature differences between plantings. Projection under future climate predicted a decline in fecundity, although this response was heterogeneous across the range. In response, we identified novel genotypes that could be introduced to genetically offset the fitness decay. Our study highlights the value of predictive models to aid seed provenancing and improve the success of revegetation projects.     

Using restoration as an experimental framework to test provenancing strategies and climate adaptability

Restoring degraded Australian landscapes through revegetation is a key concern of land holders, NGOs and government agencies. With the advent of climate change, it is increasingly important that revegetation activities take into consideration the species and provenance of plant materials to ensure that environmental plantings will be resilient to future climate conditions. A major strength of the past 30 years restoration programmes is the development of a distributed network of educated and experienced practitioners. We have recently invited stakeholders from among this network to participate in a process to cost‐effectively build Environmental Research Infrastructure – a nationally distributed network of restoration plantings that explore a broad range of research activities including a better understanding of the adaptive responses of different species and provenances. This would also facilitate long‐term monitoring of change and adaptation across Australia, providing a wealth of information to inform future conservation and restoration programmes.     

Indicators of biodiversity and carbon storage in remnant and planted vegetation in the Mount Lofty Ranges of South Australia: lessons for ‘biodiverse’ plantings

Planting of woody perennial vegetation for carbon sequestration continues to gain momentum as markets for carbon develop in Australia. With the impetus of the Clean Energy Future package, these plantings have the potential to contribute to biodiversity gains if established and managed appropriately. In this study, we sought to link indicators of biodiversity to carbon storage in remnant vegetation, mixed‐species native revegetation and single‐species eucalypt plantations in the Mount Lofty Ranges (MLR) of South Australia. Native plant species richness was higher in remnant vegetation than in revegetation and plantation sites in the southern MLR, but only remnant and plantation sites were different in the northern MLR. Native bird species richness was higher in remnant than plantation sites, but revegetation sites were similar to both plantation and remnant sites in northern and southern sites. Mean total standing carbon varied across treatments in southern sites, and there were no statistically significant differences in mean carbon sequestration rate between planted treatments. Monoculture plantation sites lack the structural complexity required and offer limited resources for native fauna compared with mixed‐species revegetation or remnant vegetation. This reinforces the importance of carefully constructed incentives to compensate landholders for potential carbon shortfalls if the opportunity for biodiversity gains from carbon plantings is to be realised in the longer term. The value of the standing carbon in remnant vegetation should also be recognised in emerging markets.     

Restoration of a coastal swamp forest in southeast Brazil

Restoration of degraded swamps often requires strong human intervention because of their fragility. In Brazil, coastal swamp forests are now much reduced by anthropogenic action. This paper investigates survival and growth performance of nine native shrub and tree species introduced into a degraded swamp invaded by exotic grasses and sedges in coastal Rio de Janeiro. Our central aim was to evaluate which species were more appropriate for use in initial stages of revegetation. Additionally, in separate field experiments, we tested statistical hypotheses that higher survival and growth performance would be found for seedlings: (a) taller in height, (b) subjected to shorter duration of flooding, and (c) planted with addition of organic matter inside the planting holes. Results were analyzed after 3 years of planting. “Planting in mounds”, and a consequent reduction on the flooding period plants are exposed to, increased survival and growth. The use of taller seedlings often increased survival, and organic matter addition increased growth. Three (Myrsine rubra, Tabebuia cassinoides, and Calyptranthes brasiliensis) out of nine species tested showed high growth- and use-viability indices, and were therefore indicated for use in revegetation programs. Interspecific variation as regards responses to the treatments applied suggests that in the future, species evaluated for this purpose, should be examined on a case-by-case basis.     

Revegetation,restoration and reptiles in rural landscapes: Insights from long‐term monitoring programmes in the temperate eucalypt woodlands of south‐eastern Australia

Over the past decade, there has been a concerted effort to better understand the distribution and abundance of reptiles in agricultural landscapes and to specifically evaluate their response to revegetation (tree and shrub plantings) and habitat restoration in the wheat‐sheep belt of south‐eastern Australia. This article reviews the response of reptiles to revegetation and woodland management and provides ten insights and lessons that can be applied to help improve reptile conservation in temperate eucalypt woodlands and fragmented agricultural landscapes in Australia. The review focuses primarily on revegetation programmes conducted by Landcare and Greening Australia, and management interventions funded by Local Land Services in NSW and Catchment Management Authorities in Victoria.     

Restoring Wetland Plant Diversity: A Comparison of Existing and Adaptive Approaches

Most restoration projects are not designed or assessed in ways that identify cause–effect relationships.When plants die, even detailed postmortem examinations cannot pinpoint causes; e.g., mortalities of 7% vs. 90% in two salt marsh transplantation projects were attributable to differences in hypersalinity and sedimentation, but other effects could not be ruled out. Adaptive restoration (the experimental testing of alternative approaches in restoration sites), however, can clarify cause–effect relationships, while simultaneously restoring plant diversity and informing future restoration efforts. Projects in Tijuana Estuary (California) and Greene Prairie (Wisconsin) demonstrate the approach: (1) A large field experiment at Tijuana Estuary showed that species-rich plantings of halophytes accelerated the development of ecosystem structure and function (over single-species plantings) while simultaneously vegetating an intertidal plain. The six-species assemblages produced more complex canopies and accumulated more biomass and nitrogen than singlespecies and unplanted plots. (2) Also at Tijuana Estuary, an experiment is testing the ability of tidal creek networks to accelerate revegetation and increase food-web support (via increased growth of plants, invertebrates, and fish) in an 8-ha project that simultaneously restored tidal flushing. (3) In Greene Prairie, the ability to establish 33 native species is being tested as replacements for an invasive grass (Phalaris arundinacea). In each case, the adaptive approach informs both the science and practice of restoration. Without experimentation, restorationists are hard-pressed to explain past mortality and to suggest better methods for restoring structure and function. Adaptive restoration can provide the knowledge required, especially when large projects are implemented as sequential modules with experiments that sequentially provide essential information.     

Establishment of woody plants for secondary and tertiary dune stabilization along the mid-Atlantic coast

Secondary and tertiary sand dunes along the Atlantic coast were originally covered with dense vegetation, including trees and shrubs. Most of this vegetation has been destroyed by various forms of development. The objective of this study was to evaluate the effects of various establishment techniques on the survival and growth of native and naturalized woody plants for secondary and tertiary dune stabilization, using bare root transplants. All plantings were made on sand dunes. The actual site was approximately 300 m from the ocean and was covered with a sparse stand of American beachgrass. Establishment variables were (a) peat moss applied in the fall, followed by fall plantings; (b) peat moss applied in the fall, followed by spring plantings; (c) peat moss applied in the spring, followed by spring plantings; and (d) no peat moss with either fall or spring plantings. Each planting included a fertilizer variable of (a) 30 g of magnesium ammonia phosphate placed 8 cm below the bottom of the planting hole; (b) 30 g of 10-6-4 fertilizer, which contained 50% of its nitrogen in an organic form, sprinkled around the base of the plant in the spring of the second growing season; and (c) no fertilizer. All plants used were 1- or 2-year-old seedlings. The use of organic soil amendments had a favorable affect on the survival of some species. Rugosa rose showed an increase in survival rate when the organic additive was added in the fall, followed by fall planting. Bayberry was favorably affected by the use of additive and regardless of planting time. The use of the two fertilizers produced no consistent or measurable response.Presented at the Seventh International Biometeorological Congress, 17–23 August 1975, College Park, Maryland, USA.     

Revegetation of a wetland following control of the invasive woody weed, Mimosa pigra, in the Northern Territory, Australia

Summary Methods for floodplain revegetation using native species were investigated, following clearance of the invasive shrub Mimosa pigra L. (Mimosaceae) in the Northern Territory of Australia. Prolific revegetation occurred naturally and several species were identified that have potential for revegetation at sites where natural regeneration is poor, namely: Spiny Mud Grass, Pseudoraphis spinescens, Awnless Barnyard Grass, Echinochloa colona, and an unidentified Panicum species. However, it may still be desirable to plant native perennial grasses, of which most species did not establish naturally. Stolons of the native floodplain grass Hymenachne acutigluma (Steud) Gilliland (Poaceae) established well when planted in wet mud and shallow water during the early dry season, as seasonal floodwaters subsided. Similar plantings during the early wet season were less successful. Sowing seed of several floodplain grasses and Eliocharis dulcis was unsuccessful in both seasons. Planting stolons of H. acutigluma as seasonal floodwaters subside may provide a reliable alternative to exotic floodplain grasses, Para Grass (Urochloa mutica), and Amity Aleman Grass (Echinochloa polystachya), which are also currently propagated vegetatively in Australia. However, planting H. acutigluma stolons had no tangible benefits in terms of suppressing Mimosa establishment, which was low in all treatments. Revegetation should not be considered an alternative to the diligent control of Mimosa seedlings; regenerating following control of Mimosa thickets.     

Growth and survival of seedlings of native plants in an impoverished and highly disturbed soil following inoculation with arbuscular mycorrhizal fungi

We investigated whether arbuscular mycorrhizas influenced growth and survival of seedlings in an extremely impoverished and highly disturbed soil. Seedlings of four plants species native to the site were either inoculated with native sporocarpic arbuscular mycorrhizal (AM) fungi or fertilised prior to transplanting, and followed over 86 weeks at the site. One treatment was also irrigated with N-rich leachate from the site. In a laboratory experiment, seedlings were fertilised with excess P for 6 weeks, and location of the P store determined. Growth and survival of AM and fertilised seedlings were similar at the site. Inoculated mycorrhizal fungi and roots appeared to extend into the surrounding soil together. P concentration in leaves of all plants was extremely low. Irrigation with leachate increased growth of seedlings. In the laboratory experiment, significantly more P was stored in roots than shoots. We suggest that successful revegetation of extremely disturbed and impoverished sites requires selection of mycorrhizal fungi and plants to suit the edaphic conditions and methods of out-planting.     

Inoculation of Woody Legumes with Selected Arbuscular Mycorrhizal Fungi and Rhizobia To Recover Desertified Mediterranean Ecosystems

Revegetation strategies, either for reclamation or for rehabilitation, are being used to recover desertified ecosystems. Woody legumes are recognized as species that are useful for revegetation of water-deficient, low-nutrient environments because of their ability to form symbiotic associations with rhizobial bacteria and mycorrhizal fungi, which improve nutrient acquisition and help plants to become established and cope with stress situations. A range of woody legumes used in revegetation programs, particularly in Mediterranean regions, were assayed. These legumes included both exotic and native species and were used in a test of a desertified semiarid ecosystem in southeast Spain. Screening for the appropriate plant species-microsymbiont combinations was performed previously, and a simple procedure to produce plantlets with optimized mycorrhizal and nodulated status was developed. The results of a 4-year trial showed that (i) only the native shrub legumes were able to become established under the local environmental conditions (hence, a reclamation strategy is recommended) and (ii) biotechnological manipulation of the seedlings to be used for revegetation (by inoculation with selected rhizobia and mycorrhizal fungi) improved outplanting performance, plant survival, and biomass development.     

Ecological restoration, carbon sequestration and biodiversity conservation: The experience of the Society for Wildlife Research and Environmental Education (SPVS) in the Atlantic Rain Forest of Southern Brazil

Since 1999, SPVS has been involved in three projects that combine two fundamental goals over the course of 40 years: the conservation of one of Brazil's most important remnants of Atlantic Forest and the implementation of projects for carbon sequestration. In addition, there is an interest in replicating these projects in order to restore other degraded areas, protect the Brazilian biomes, and help to diminish deforestation and forest fire, therefore reducing carbon emissions. The acquisition of 19,000 ha of degraded areas of high biological importance in southern Brazil was the first step towards the implementation of the projects. These areas are owned by SPVS, a Brazilian NGO, and are being restored, conserved and transformed into Private Natural Reserves, in partnership with the NGO – The Nature Conservancy, and financed by the companies – American Electric Power, General Motors and Chevron Texaco. The process of forest restoration involves several stages: soil studies, surveying the region's native plants, planning for restoration by means of a Geographical Information System, production of seedlings, application of different techniques for planting (such as manual or mechanised planting with seedlings and stakes), and biomass and biodiversity monitoring. To guarantee the survival of the seedlings on the planted areas, during the first three years, there is a continuous and systematic maintenance programme including weeding of undergrowth, crowing and organic fertilisation. The three projects already planted around 500,000 seedlings of native species until September 2004, and aim to plant a further 300,000 until 2008.     

Effects of Stream Restoration on Woody Riparian Vegetation of Southern Appalachian Mountain Streams,North Carolina,U.S.A

Riparian revegetation, such as planting woody seedlings or live stakes, is a nearly ubiquitous component of stream restoration projects in the United States. Though evaluations of restoration success usually focus on in‐stream ecosystems, in order to understand the full impacts of restoration the effects on riparian ecosystems themselves must be considered. We examined the effects of stream restoration revegetation measures on riparian ecosystems of headwater mountain streams in forested watersheds by comparing riparian vegetation structure and composition at reference, restored, and degraded sites on nine streams. According to mixed model analysis of variance (ANOVA), there was a significant effect of site treatment on riparian species richness, basal area, and canopy cover, but no effect on stem density. Vegetation characteristics at restored sites differed from those of reference sites according to all metrics (i.e. basal area, canopy cover, and species composition) except species richness and stem density. Restored and degraded sites were structurally similar, with some overlap in species composition. Restored sites were dominated by Salix sericea and Cornus amomum (species commonly planted for revegetation) and a suite of disturbance‐adapted species also dominant at degraded sites. Differences between reference and restored sites might be due to the young age of restored sites (average 4 years since restoration), to reassembly of degraded site species composition at restored sites, or to the creation of a novel anthropogenic ecosystem on these headwater streams. Additional research is needed to determine if this anthropogenic riparian community type persists as a resilient novel ecosystem and provides valued riparian functions.     

Restoring Forbs for Sage Grouse Habitat: Fire, Microsites, and Establishment Methods

Abstract The decline and range reduction of sage grouse populations are primarily due to permanent loss and degradation of sagebrush–grassland habitat. Several studies have shown that sage grouse productivity may be limited by the availability of certain preferred highly nutritious forb species that have also declined within sagebrush ecosystems of the Intermountain West, U.S.A. The purpose of this study was to determine the suitability of three species of forbs for revegetation projects where improving sage grouse habitat is a goal. Species suitability was determined by evaluating the emergence, survival, and reproduction of Crepis modocensis, C. occidentalis, and Astragalus purshii in response to method of establishment (seeding or transplanting), site preparation treatment (burned or unburned), and microsite (mound or interspace) in an Artemisia tridentata ssp. wyomingensis vegetation association in south central Oregon. For seeded plants A. purshii had the lowest emergence (8%) of all three species. Both seeded Crepis species had similar overall emergence (38%). Significantly more Crepis seedlings emerged from shrub mounds in unburned areas (50%) than in any other fire‐by‐microsite treatment (33 to 36%). Approximately 10% more Crepis seedlings survived in mounds compared with interspaces. Nearly twice as many emerging Crepis seedlings survived in the burned areas as opposed to unburned areas (p < 0.01). This resulted in more plant establishment in burned mounds despite higher emergence in unburned mounds. Astragalus purshii seedlings also survived better in burned areas (p = 0.06) but had no differential response to microsite. Fire enhanced survival of both Crepis and A. purshii transplants (p = 0.08 and p = 0.001). We believe additional research is needed to improve A. purshii emergence before it will become an effective plant for restoring sage grouse habitat. Conversely, we conclude that these Crepis species provide a viable revegetation option for improving sage grouse habitat in south central Oregon.