Factors Affecting Seed Germination and Seedling Establishment of Fen-Meadow Species

Availability of seeds and provision of “safe sites” for seedling recruitment are essential for successful restoration of seminatural grassland communities. Inability to provide species‐specific conditions for seedling recruitment appears to be a major factor limiting establishment of fen‐meadow species on restoration sites. This contention was tested in the field for both germination and establishment conditions for a selection of fen‐meadow species. A Cirsio‐Molinietum fen meadow and an agriculturally semi‐improved species‐poor grass dominated rush pasture were used. Seeds of Carex ovalis, Cirsium dissectum, Molinia caerulea, Succisa pratensis, and Holcus lanatus were sown onto treatments comprising either irrigation or no irrigation, presence or absence of existing vegetation canopy, and presence or absence of soil disturbance. Germination of all except H. lanatus was higher in the fen meadow than in the rush pasture. The fen‐meadow site was less susceptible to drought, provided more light to the seed environment, and showed a stronger day–night variation in relative humidity compared with the rush pasture. All the fen‐meadow species responded strongly to the experimental treatments, whereas H. lanatus showed only a small response. Soil disturbance was the major factor that increased germination. Removal of the vegetation canopy improved germination only in S. pratensis. Conditions affecting survival of seedlings were different from those affecting seed germination. Seedling survival was greater on the fen‐meadow site than on the rush pasture. Canopy presence was the major factor that reduced seedling survival. Few seedlings survived in the presence of the rush pasture canopy. Irrigation and soil disturbance were of minor importance for seedling survival on both sites. Safe sites for seed germination and seedling establishment of fen‐meadow species existed on the fen meadow even without soil disturbance and gap creation. Safe sites for seedling recruitment were not present in the rush pasture. The need for species‐specific definition of safe site characteristics at the two stages of seedling recruitment (i.e., for seed germination and for seedling survival) was demonstrated. The implications of these findings for restoration of seminatural grasslands are discussed.     

Wetland Restoration and Invasive Species: Apple snail (Pomacea insularum) Feeding on Native and Invasive Aquatic Plants

The apple snail Pomacea insularum is an aquatic invasive gastropod native to South America that has the potential to cause harm to aquatic ecosystems, wetland restoration, and agriculture. To predict the potential impact of this snail on aquatic ecosystems, we tested the feeding rate of P. insularum , under laboratory nonchoice experiments, for 3 species of invasive macrophytes and 13 species of native aquatic plants that are important for wetland restoration and health. High levels of consumption were recorded for four native species ( Ceratophyllum demersum , Hymenocallis liriosme , Ruppia maritima , and Sagittaria lancifolia ) and three invasive species ( Colocasia esculenta , Alternanthera philoxeroides , and Eichhornia crassipes ). In contrast, less than 10% of the biomass of Spartina alterniflora , Scirpus californicus , Thalia dealbata , and Typha latifolia was consumed by P. insularum over the test period. The palatability of macrophytes was negatively correlated with dry matter content, making our results generalizable to all regions where this invader may be present. Based on our results, wetland restoration in areas invaded by P. insularum should focus on emergent structural species with low palatability. Apple snails should not be considered as agents of biocontrol for invasive plants; although apple snails fed on invasive plants at a high rate, their consumption of many native species was even greater.     

Approaches to Selecting Native Plant Replacements for Fleshy-Fruited Invasive Species

Invasive plants are a serious threat to biodiversity. Yet, in some cases, they may play an important ecological role in heavily modified landscapes, such as where fleshy‐fruited invasive plants support populations of native frugivores. How can such conservation conflicts be managed? We advocate an approach in which native fleshy‐fruited plants are ranked on their ability to provide the fruit food resources for native frugivores currently being provided by invasive plants. If these native taxa are preferentially used, where ecologically appropriate, in plantings for restoration and in park and garden settings, they could help support native frugivore populations in the event of extensive invasive plant control. We develop and critically examine six approaches to selecting candidate native plant taxa: a multivariate approach based on the frugivore assemblage, a scoring model, and several multivariate approaches (including trait combinations having the greatest correlation with the diet of the native frugivore assemblage) based on the functional traits of fruit morphology, phenology, conspicuousness, and accessibility. To illustrate these approaches, we use a case study with Bitou bush (Chrysanthemoides monilifera subsp. rotundata) (Asteraceae), an Australian Weed of National Significance. The model using a dissimilarity value generated from all available traits identified a set of species used by the frugivores of C. monilifera more than null models. A replacement approach using species ranked by either all traits available or the frugivore community appears best suited to guide selection of plants in restoration practice.     

Influence of Invasive Tree Kill Rates on Native and Invasive Plant Establishment in a Hawaiian Forest

Fire tree (Morella faya) has invaded extensive areas of wet and mesic forest on the Island of Hawai’i, forming nearly monospecific stands. Our objective was to identify a method of controlling M. faya, which would allow native plants to establish while minimizing establishment by invasive plants. Treatments (logging all trees, trees left standing but girdled, and incremental girdling over 20 months) were selected to kill M. faya stands at different rates, thereby creating different conditions for species establishment. Leaf litter was either removed or left in place; seeds and seedlings of three native pioneer species, three native forest species, and three alien invasive species were then added to determine their ability to establish. Native pioneer species established best in the log and girdle treatments, whereas seedling emergence of native forest species was higher in the girdle and incremental girdle treatments. Seedlings of invasive species emerged faster than the natives, but each of them responded differently to the stand treatments. Leaf litter reduced seedling emergence for all species, with small‐seeded species (<1 mg/seed) affected most under low light conditions. No single method eliminated all invaders, but girdling of M. faya provided suitable conditions for most native species. If combined with selective removal of the most disruptive alien species and native seed additions, girdling could be an effective general strategy for restoring native forests that have been overwhelmed by woody invaders.     

Diversity of Regenerating Plants in Reforestations with Araucaria angustifolia (Bertol.) O. Kuntze of 12, 22, 35, and 43 Years of Age in Paraná State, Brazil

In the current context of intense forest fragmentation and consequent loss of biodiversity, commercial reforestations have gained special attention in conservation biology because the colonization of the understory in these wooded areas may result in a considerable number of species. A record was made of the regenerating species in the understory of reforestations with Araucaria angustifolia at planting ages of 12, 22, 35, and 43 years, located in the central east region of Paraná State, Brazil. In total, an area of 1,200 m² was sampled, with 231 recorded species belonging to 60 botanical families. Species diversity and richness increased with planting age up to 35 years. Canopy cover was the variable that best explained the colonization of the understory in some stages. Maintenance activities in the reforestations over the years selected species capable of germinating or sprouting and growing rapidly. However, our results show that A. angustifolia commercial reforestations are home to many native plant species. Thus, the objectives of commercial reforestation can be harmonized with the interests of conservation biology, applying management alternatives with the aim of changing current forestry models.     

Restoration Ecology of an Endangered Plant Species: Establishment of New Populations of Cirsium pitcheri

We determined the effects of shade, burial by sand, simulated herbivory, and fertilizers on the survival and growth of artificially planted population of Cirsium pitcheri—an endangered plant species of the sand dunes along Lake Huron. Sand burial experiments showed that greenhouse grown plants should optimally be transplanted into areas receiving 5 cm of sand deposition: burial at this depth maximized emergence, survivorship, and below‐ground biomass. Under field conditions, simulated herbivory of up to 50% of the plant height produced a slight increase in biomass after one year of growth. Field observations showed that when white‐tailed deer removed more than 50% of the transplant's leaf tissue, the plant died. The application of a 20:20:20 (N:P:K) water‐soluble fertilizer produced a significant increase in the dry leaf biomass, total leaf area, and total dry biomass relative to control plants. We also tested for the presence or absence of a persistent seed bank. Few seeds were recovered from soil samples collected from Pinery Provincial Park and Providence Bay. However, C. pitcheri has the ability to form a persistent seed bank under field conditions but only at soil depths of 15 cm. Cirsium pitcheri seeds are able to germinate and seedlings can emerge from a burial depth of up to 6 cm. Thus, seeds planted in open, sunny areas will probably maximize emergence, growth, and survivorship of seedlings. Populations of C. pitcheri can be restored by planting seeds at shallow depths, transplanting greenhouse‐grown plants, applying water soluble fertilizers, and protecting plants from herbivores.     

Restoration of a Forest Understory After the Removal of an Invasive Shrub, Amur Honeysuckle (Lonicera maackii)

The recruitment of native seedlings is often reduced in areas where the invasive Amur honeysuckle (Lonicera maackii) is abundant. To address this recruitment problem, we evaluated the effectiveness of L. maackii eradication methods and restoration efforts using seedlings of six native tree species planted within eradication and unmanipulated (control) plots. Two eradication methods using glyphosate herbicide were evaluated: cut and paint and stem injection with an EZ‐Ject lance. Lonicera maackii density and biomass as well as microenvironmental characteristics were measured to study their effects on seedling growth and survivorship. Mean biomass of Amur honeysuckle was 361 ± 69 kg/ha, and density was 21,380 ± 3,171 plants/ha. Both eradication treatments were effective in killing L. maackii (≥ 94%). The injection treatment was most effective on large L. maackii individuals (>1.5 cm diameter), was 43% faster to apply than cutting and painting and less fatiguing for the operator, decreased operator exposure to herbicide, and minimized impact to nontarget vegetation. Deer browse tree protectors were used on half of the seedlings, but did not affect survivorship or growth. After 3 years, survival of native seedlings was significantly less where L. maackii was left intact (32 ± 3%) compared with the eradication plots (p < 0.002). Seedling survival was significantly different between cut (51 ± 3%) and injected (45 ± 3%) plots. Species had different final percent survival and rates of mortality. Species survival differed greatly by species (in descending order): Fraxinus pennsylvanica > Quercus muehlenbergii ≥ Prunus serotina≥ Juglans nigra > Cercis canadensis > Cornus florida. Survivorship and growth of native seedlings was affected by a severe first‐year drought and by site location. One site exhibited greater spring soil moisture, pH, percent open canopy, and had greater survivorship relative to the other site (55 ± 2 vs. 30 ± 2%). Overall, both L. maackii eradication methods were successful, but restorationists should be aware of the potential for differential survivorship of native seedlings depending on species identity and microenvironmental conditions.     

The Ants of the Juan Fernández Islands: Genesis of an Invasive Fauna

A first study of the ants on the three main islands of the Juan Fernández Archipelago (Chile) has revealed the presence of just three species, Hypoponera confinis, Linepithema humile, and Tetramorium bicarinatum, all widely distributed invasive species. Most notable among them is the Argentine ant, L. humile, an ecologically destructive species that has established several populations and appears to be expanding.     

Alien Abduction: Disruption of Native Plant-Pollinator Interactions by Invasive Species

The indirect impacts of Shorea siamensis‐logging on the reproductive ecology of Dipterocarpus obtusifolius, a self‐incompatible butterfly‐, moth‐, and bird‐pollinated tree, were studied in tropical dry forest in Thailand. Pollinator activity at D. obtusifolius trees and subsequent seed production were recorded in three forest areas subject to differing intensities of S. siamensis extraction. The pollinator and plant understory communities in these areas were also noted. Forest areas subject to high S. siamensis extraction intensities had very high understory flowering plant cover, dominated by the exotic invader Chromolaena odorata. Activity of butterfly pollinators at D. obtusifolius trees decreased in these disturbed areas, although their abundance remained comparable to other forest areas subject to only moderate or no extraction. For sphingid moth pollinators, there was no difference across differentially disturbed forest areas in either abundance or in the proportion bearing pollen. Pollinator activity by birds increased at highly disturbed locations but was not sufficient to offset a decline in overall pollinator activity at D. obtusifolius canopies in areas of heavy 5. siamensis extraction. Thus, extraction of S. siamensis indirectly affected the pollination of D. obtusifolius, primarily by causing changes in the foraging behavior of butterfly pollinators rather than their abundance. A shift in the relative abundance of floral nectar resources from the canopy to the understory, a consequence of 5. siamensis extraction and invasion by C. odorata, led to a parallel shift in foraging location of the principal diurnal pollinators, the butterflies, toward the understory. Despite reduced pollination at disturbed sites, behavioral changes did not translate into a D. obtusifolius seed set effect, possibly because pollination by birds (or moths) at the disturbed site compensated for reduced butterfly pollination.     

Integration of Biological Control and Native Seeding to Restore Invaded Plant Communities

Disturbed natural areas frequently experience invasion by introduced plant species that can reduce native biodiversity. Biological control can suppress these introduced species, but without restoration another introduced species can invade. Integration of biological control with concurrent revegetation can both aid in weed reduction via interspecific plant competition and establish a restored native plant community. This 3‐year study investigated an integrated approach to controlling the introduced annual Mile‐a‐minute weed (Persicaria perfoliata [L.] H. Gross [Polygonaceae]) using the biocontrol weevil Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) and restoration planting using a native seed mix. A fully factorial design tested weevils and seeding, separately and together, using insecticide to eliminate weevils. The weevils together with the native seed mix reduced P. perfoliata percent cover in 2009 and 2010, and peak seed cluster production in 2010, compared to the insecticide ? no seed control treatment. Persicaria perfoliata final dry biomass was reduced by 75% in 2010 and by 57% in 2011 in the weevils plus seed treatment compared to the control, with weevils having the greatest effect in 2010 and the seed treatment having the greatest impact in 2011. Results suggest an additive effect of biocontrol and seeding in suppressing P. perfoliata. Seeded treatments also developed the highest native plant species richness and diversity, comprised of spontaneous recolonization in addition to species from the seed mix. Results support the use of integrated management of this invasive weed, with suppression through biological control and native revegetation together helping prevent reinvasion while restoring native plant biodiversity.     

Genetic Structure of Threatened Native Populations and Propagules Used for Restoration in a Clonal Species,American Beachgrass (Ammophila breviligulata Fern.)

An important goal of native plant restorations was to reconstitute populations that are genetically similar to native ones, thereby increasing the probably of successful establishment and persistence. We examined the extent to which this goal has been accomplished in Great Lakes restorations of Ammophila breviligulata Fern., a beachgrass species that is widely used for habitat restoration and is considered threatened in the study areas. In parallel studies on Lake Michigan and Lake Superior, we used polymorphic Intersimple Sequence Repeat markers to assess genetic similarity between well‐established and new native populations, restored populations, and restoration propagules obtained from two commercial suppliers. Native populations were generally more diverse than expected for a clonal species, whereas the commercially cultivated releases were monotypic. One of the commercial releases used in Minnesota was exclusively found in restored populations and did not occur in any other native population at this site. The propagules used in the newly planted restoration in Illinois were derived from a release that commercial suppliers maintain was derived from a native Michigan population, as opposed to a selected release. Diversity in this restoration was equivalent to that native Illinois’ populations; however, many of the genotypes were not of local origin. Overall, study underscores the importance of obtaining baseline genetic surveys of remnant native populations and restoration propagules before restoration efforts are initiated, especially when the populations are threatened or endangered.     

Exposure to herbivores increases seedling growth and survival of American chestnut (Castanea dentata) through decreased interspecific competition in canopy gaps

The successful development of early stages of blight‐resistant hybrid stock has increased hopes for restoration of American chestnut (Castanea dentata) to eastern North American forests. However, these forests have undergone substantial ecological change in the century since the functional extirpation of American chestnut, and it remains unknown to what extent American chestnut will be able to recolonize contemporary forests. In particular, high densities of white‐tailed deer (Odocoileus virginianus) and competition with mesophytic tree species such as maple (Acer) may impede chestnut regeneration, much as they affect oak (Quercus). We used a split‐plot analysis of variance (ANOVA) design to examine the effects of canopy gaps and herbivory on survival and growth of third generation backcrossed (BC₃) hybrid chestnut seedlings over two growing seasons in central Indiana, U.S.A. Only 4 of 588 (0.7%) seedlings in closed‐canopy plots survived to the end of the study, as opposed to 264 of 589 (45%) seedlings in gap plots. Within the gap treatment, fencing was associated with reduced chestnut survival as well as reduced herbivory and increased cover of non‐chestnut vegetation. Our results indicate that herbivory may indirectly benefit chestnut regeneration by suppressing competition. However, this beneficial effect is likely context‐dependent and additional work is needed to establish the conditions under which it occurs.     

Succession of Exotic and Native Species Assemblages within Restored Floodplain Forests: A Test of the Parallel Dynamics Hypothesis

Exotic plants pose a threat to restoration success in post‐agricultural bottomlands, but little information exists on their dynamics during succession of actively restored sites. We hypothesized that exotic assemblages would establish during succession and that their compositional trends during succession time would mirror those published for native species in other systems, with an early peak in herbaceous richness followed by a decline as woody species establish. In the summer of 2008, we sampled 16 sites across an 18‐year chronosequence of restored forests, with an additional four mature forest stands for comparison, within the Cypress Creek NWR, Illinois, U.S.A. We identified all vascular plant species and quantified canopy openness at three canopy strata, and soil texture and chemistry. Trends in exotic assemblages were significantly correlated with canopy openness at all strata. Richness of exotic and native herbaceous species was related to stand age and consistent with a Weibull regression model. Native and exotic herbaceous cover followed an exponential decay model. Woody native richness over time conformed to a logistic model; woody exotics exhibited no relationship with stand age and were present in sites of all ages. Our results indicate that although their rates of decline differ, herbaceous exotics and natives exhibit similar successional dynamics; therefore, herbaceous exotics may not pose a lasting threat to restoration success in reforested floodplains. Woody exotics can establish across a range of successional stages and persist under closed canopy conditions. Bottomland restorations are vulnerable to the invasion and expansion of exotic plant species even after canopy closure.     

Recovery of Native Grasslands after Removing Invasive Pines

The advance of exotic tree and shrub species is one of the main threats to conservation of the last relicts of natural grassland in South America; however, control actions in the region are still scarce and there are almost no evaluations of the recovery of natural ecosystems after removing invasive plants. Monitoring of the vegetation during the years after removal of invasive trees is critical in order to decide whether an active restoration strategy is necessary. The recovery of montane grassland four years after the control of a dense invasion of Aleppo pine (Pinus halepensis) is described in this study. Experimental clearing areas were followed during four years and compared to grassland controls. Variation was seen in the levels of recovery in function of the proximity of sectors of grassland that are free of invasive species and/or the density of invasive trees before control. Native species slowly replaced many exotic herbs that had appeared as pioneers, there was low recruitment of pine seedlings in spite of the quantity of seeds from trees that surrounded the clearings, and species richness and diversity were restored, including cover of the typical grasses in the controls. Recovery of grassland after felling was shown to be successful and does not seem to be seed limited if tree removal occurs early in the invasion process.     

Red oak seedlings as indicators of deer browse pressure: Gauging the outcome of different white‐tailed deer management approaches

After decades of high deer populations, North American forests have lost much of their previous biodiversity. Any landscape‐level recovery requires substantial reductions in deer herds, but modern societies and wildlife management agencies appear unable to devise appropriate solutions to this chronic ecological and human health crisis. We evaluated the effectiveness of fertility control and hunting in reducing deer impacts at Cornell University. We estimated spring deer populations and planted Quercus rubra seedlings to assess deer browse pressure, rodent attack, and other factors compromising seedling performance. Oak seedlings protected in cages grew well, but deer annually browsed ≥60% of unprotected seedlings. Despite female sterilization rates of >90%, the deer population remained stable. Neither sterilization nor recreational hunting reduced deer browse rates and neither appears able to achieve reductions in deer populations or their impacts. We eliminated deer sterilization and recreational hunting in a core management area in favor of allowing volunteer archers to shoot deer over bait, including at night. This resulted in a substantial reduction in the deer population and a linear decline in browse rates as a function of spring deer abundance. Public trust stewardship of North American landscapes will require a fundamental overhaul in deer management to provide for a brighter future, and oak seedlings may be a promising metric to assess success. These changes will require intense public debate and may require new approaches such as regulated commercial hunting, natural dispersal, or intentional release of important deer predators (e.g., wolves and mountain lions). Such drastic changes in deer management will be highly controversial, and at present, likely difficult to implement in North America. However, the future of our forest ecosystems and their associated biodiversity will depend on evidence to guide change in landscape management and stewardship.     

Commonly Rare and Rarely Common: Comparing Population Abundance of Invasive and Native Aquatic Species

Invasive species are leading drivers of environmental change. Their impacts are often linked to their population size, but surprisingly little is known about how frequently they achieve high abundances. A nearly universal pattern in ecology is that species are rare in most locations and abundant in a few, generating right-skewed abundance distributions. Here, we use abundance data from over 24,000 populations of 17 invasive and 104 native aquatic species to test whether invasive species differ from native counterparts in statistical patterns of abundance across multiple sites. Invasive species on average reached significantly higher densities than native species and exhibited significantly higher variance. However, invasive and native species did not differ in terms of coefficient of variation, skewness, or kurtosis. Abundance distributions of all species were highly right skewed (skewness>0), meaning both invasive and native species occurred at low densities in most locations where they were present. The average abundance of invasive and native species was 6% and 2%, respectively, of the maximum abundance observed within a taxonomic group. The biological significance of the differences between invasive and native species depends on species-specific relationships between abundance and impact. Recognition of cross-site heterogeneity in population densities brings a new dimension to invasive species management, and may help to refine optimal prevention, containment, control, and eradication strategies.     

Native Species for Roadslope Revegetation: Selection,Validation, and Cost Effectiveness

Native species arise as an alternative to improve the poor success of traditional hydroseeding with commercial species in degraded areas. The objectives of this study were to (1) establish a procedure to select suitable native species for roadslope revegetation, (2) validate the procedure by means of field sowing experiments, and (3) assess cost effectiveness of the use of native species in hydroseeding as regards commercial ones. Vegetation surveys were performed in semiarid roadslopes of East Spain and species success evaluated according to abundance and frequency. A list of potentially suitable species for revegetation was produced and a subset of species selected and hydroseeded to check their suitability in hydroseeding. Cost effectiveness of the use of native species was estimated. Results support the suitability of the procedure for the selection of native species. Vegetation cover produced by the hydroseeded mixture of native species was high (between 43 and 70% throughout the 4 years) and was 4–20 times higher than the cover produced by a standard commercial seed mixture. The price of the selected seed mixture was 30 times that of the commercial one, but the cost of relevant ecological advantages provided by the use of native species was only twice that of the commercial species on the basis of cost effectiveness assessment. Practical consequences for restorers, policymakers, and practitioners are discussed, and the use of native species is encouraged to improve revegetation success of roadslopes and similar slope types especially in semiarid and arid environments.     

Relationships between Methylobacteria and Glyphosate with Native and Invasive Plant Species: Implications for Restoration

After removing invasive plants, whether by herbicides or other means, typical restoration design focuses on rebuilding native plant communities while disregarding soil microbial communities. However, microbial–plant interactions are known to influence the relative success of native versus invasive plants. Therefore, the abundance and composition of soil microorganisms may affect restoration efforts. We assessed the effect of herbicide treatment on phytosymbiotic pink‐pigmented facultative methylotrophic (PPFM) bacteria and the potential consequences of native and invasive species establishment post‐herbicide treatment in the lab and in a coastal sage scrub (CSS)/grassland restoration site. Lab tests showed that 4% glyphosate reduced PPFM abundance. PPFM addition to seeds increased seedling length of a native plant (Artemisia californica) but not an invasive plant (Hirschfeldia incana). At the restoration site, methanol addition (a PPFM substrate) improved native bunchgrass (Nassella pulchra) germination and size by 35% over controls. In a separate multispecies field experiment, PPFM addition stimulated the germination of N. pulchra, but not that of three invasive species. Neither PPFM nor methanol addition strongly affected the growth of any plant species. Overall, these results are consistent with the hypothesis that PPFMs have a greater benefit to native than invasive species. Together, these experiments suggest that methanol or PPFM addition could be useful in improving CSS/grassland restorations. Future work should test PPFM effects on additional species and determine how these results vary under different environmental conditions.     

Ecological Restoration of Native Forest at Aratiatia, North Island, New Zealand

Successional pathways in native forest, planted 15–33 years ago on reconstructed surfaces to restore aesthetic values destroyed by hydro‐electric dam construction at Aratiatia, central North Island, New Zealand, were compared with those on similar surfaces left unplanted. Only native species were planted. Classification identified three canopy communities and several ground layer communities with significant inter‐stratum relationships: Pittosporum tenuifolium‐Sophora tetraptera short forest with ground layers dominated by litter; P. tenuifolium‐Kunzea ericoides short forest over adventive grasses on planted sites; and adventive Cytisus scoparius shrubland over grasses on unplanted sites. Planted communities mirror young secondary forests on intact substrates in the district, but have lower density and similar or higher basal area than such forests elsewhere. Established seedlings of seven planted canopy trees, mostly early successional bird‐dispersed species, are reasonably widespread in floristically rich Pittosporum‐Sophora forest. Seedlings of only two species are widespread in floristically poor Pittosporum‐Kunzea forest, and none on unplanted sites. This first large‐scale attempt at ecological restoration in New Zealand, by mass planting of new surfaces with early successional native woody species, has created aesthetically‐pleasing stands of indigenous forest on sites which would otherwise remain in relatively stable adventive shrubland communities for the foreseeable future. Only continued monitoring will show whether further management is necessary and whether natural processes are operating at a level sufficient to ensure that artificially initiated successions will continue along more or less natural pathways.     

Resilience of Native Plant Community Following Manual Control of Invasive Cinchona pubescens in Galápagos

As invasive plant species are a major driver of change on oceanic islands, their control is an important challenge for restoration ecology. The post‐control recovery of native vegetation is crucial for the treatments to be considered successful, but few studies have evaluated the effects of control measures on both target and non‐target species. To investigate the efficiency of manual control of Cinchona pubescens and its impacts on the sub‐tropical highland vegetation of Santa Cruz Island, Galápagos, vegetation was sampled before and up to two years after control was carried out in permanent sampling plots. Manual control significantly reduced Cinchona density. Due to regeneration from the seed or bud bank, follow‐up control is required, however, for long‐term success. Despite heavy disturbance from tree uprooting, herbaceous angiosperms were little affected by the control actions, whereas dominant fern species declined in cover initially. Most native, endemic, and other introduced species regained their pre‐control levels of cover 2 years after control; some species even exceeded them. The total number of species significantly increased over the study period, as did species diversity. The native highland vegetation appeared to be resilient, recovering to a level probably more characteristic of the pre‐invasion state without human intervention after Cinchona control. However, some introduced species seemed to have been facilitated by the control actions, namely Stachys agraria and Rubus niveus. Further monitoring is needed to confirm the long‐term nature of vegetation change in the area.