Young restored forests increase seedling recruitment in abandoned pastures in the Southern Atlantic rainforest

Planting seedlings is a common technique for abandoned pastures restoration in the tropics, supposedly by increasing the seedling recruitment and accelerating succession. In this study we evaluated the role of a young restored forest (one year old) in enhancing seedling establishment from two sources (seed rain and seed bank), in the Atlantic Rainforest region in Southern Brazil. We compared abandoned pasture, young restored forest and old-growth forest with respect to the seedlings recruited from different sources, by monitoring 40 permanent plots (0.5 m x 0.5 m) over 20 months. From the three studied areas a total of 392 seedlings of 53 species were recruited. Species were mainly herbaceous (85%), pioneers (88%), zoochorous (51%) and small-seeded species (60%). Seedling recruitment from the seed bank (density and species richness) was higher and dominated by herbaceous species in the abandoned pasture and in the young restored forest; on the other hand, the recruitment of woody species from seed rain was more pronounced in the old-growth forest. The young restored forest increased the species richness of woody seedlings recruitment from the seed bank (two-fold) and from seed rain (three-fold) compared to the abandoned pasture. Also, the seedling density in young restored forest was still higher than abandoned pastures (seed bank: four times; seed rain: ten times). Our results show that even young restored areas enhance the establishment of woody species and should be considered an important step for pasture restoration.     

Colonization of woody seedlings in the understory of actively and passively restored tropical moist forests

The status of woody seedling colonization gives clues about the self‐sustainability of restored forests, a tenet of restoration success. Little is known about woody seedling colonization in restored afrotropical forests. We evaluated effects of restoration methods (active vs. passive), sampling year, restoration age, and distance from old‐growth forests on seedling colonization in restored afrotropical moist forests. Seedlings were measured in 2011 and 2014 in 71 clusters of 284 permanent sampling plots (12.6 m² each) in actively (initially 3–16 years old) and 21 clusters of 63 plots in passively restored forests (initially 16 years old) in Kibale National Park, western Uganda. Seedlings were also measured in nearby old‐growth forests in three clusters of five plots in 2014. We determined species diversity, richness, abundance per plot, and species composition as measures of seedling colonization in restored and old‐growth forests. We found that diversity, richness, and abundance of seedlings were significantly higher in passively than actively restored forests. Diversity and richness but not abundance significantly increased between sampling years and with restoration age. Distance from old‐growth forests did not significantly affect diversity, richness, and abundance. Species composition of actively and passively restored forests was different from that of old‐growth forests after 19 years since restoration started. Our results show that passive restoration should be the preferred method for recovering afrotropical forests, and highlight the effect of continued management on biodiversity of restored forests.     

Ecosystem Services from Keystone Species: Diversionary Seeding and Seed‐Caching Desert Rodents Can Enhance Indian Ricegrass Seedling Establishment

Seeds of Indian ricegrass (Achnatherum hymenoides), a native bunchgrass common to sandy soils on arid western rangelands, are naturally dispersed by seed‐caching rodent species, particularly Dipodomys spp. (kangaroo rats). These animals cache large quantities of seeds when mature seeds are available on or beneath plants and recover most of their caches for consumption during the remainder of the year. Unrecovered seeds in caches account for the vast majority of Indian ricegrass seedling recruitment. We applied three different densities of white millet (Panicum miliaceum) seeds as “diversionary foods” to plots at three Great Basin study sites in an attempt to reduce rodents' over‐winter cache recovery so that more Indian ricegrass seeds would remain in soil seedbanks and potentially establish new seedlings. One year after diversionary seed application, a moderate level of Indian ricegrass seedling recruitment occurred at two of our study sites in western Nevada, although there was no recruitment at the third site in eastern California. At both Nevada sites, the number of Indian ricegrass seedlings sampled along transects was significantly greater on all plots treated with diversionary seeds than on non‐seeded control plots. However, the density of diversionary seeds applied to plots had a marginally non‐significant effect on seedling recruitment, and it was not correlated with recruitment patterns among plots. Results suggest that application of a diversionary seed type that is preferred by seed‐caching rodents provides a promising passive restoration strategy for target plant species that are dispersed by these rodents.     

Roles of Birds and Bats in Early Tropical-Forest Restoration

Restoration of tropical forest depended in large part on seed dispersal by fruit-eating animals that transported seeds into planted forest patches. We tested effectiveness of dispersal agents as revealed by established recruits of tree and shrub species that bore seeds dispersed by birds, bats, or both. We documented restoration of dispersal processes over the first 76 months of experimental restoration in southern Mexico. Mixed-model repeated-measures randomized-block ANOVAs of seedlings recruited into experimental controls and mixed-species plantings from late-secondary and mature forest indicated that bats and birds played different roles in the first years of a restoration process. Bats dispersed pioneer tree and shrub species to slowly regenerating grassy areas, while birds mediated recruitment of later-successional species into planted stands of trees and to a lesser extent into controls. Of species of pioneer trees and shrubs established in plots, seven were primarily dispersed by birds, three by bats and four by both birds and bats. Of later-successional species recruited past the seedling stage, 13 were of species primarily dispersed by birds, and six were of species dispersed by both birds and bats. No later-successional species primarily dispersed by bats established in control or planted plots. Establishment of recruited seedlings was ten-fold higher under cover of planted trees than in grassy controls. Even pre-reproductive trees drew fruit-eating birds and the seeds that they carried from nearby forest, and provided conditions for establishment of shade-tolerant tree species. Overall, after 76 months of cattle exclusion, 94% of the recruited shrubs and trees in experimental plots were of species that we did not plant.     

Direct topsoil transfer to already planted reforestation sites increases native plant understory and not ruderals

Forests restored passively or by tree planting can take many decades to be recolonized by native forest understory plant species, if at all. Our study tested (1) the ability of forest topsoil transfer to accelerate the recovery of native forest plant communities in post-agricultural reforestation sites after tree-planting and without previous topsoil removal and (2) the effect of adding combinations of woody debris (WD), shrub plantings, and shade shelters (SS) on top of the transferred topsoil. Five 12.5 × 10 m treatment blocks were established in each of three recipient sites, which included two post-agricultural reforestation sites, and one abandoned gravel pit site. Each treatment blocks received forest topsoil and a combination of additional treatments. Treatment and control plots were sampled for all vascular species in spring and summer. Native forest plant species richness in topsoil recipient plots was similar (p > 0.05) to that of mature donor forest sites, and significantly higher (p < 0.05) than that of passive control plots in the recipient sites. The plant community composition of all topsoil recipient plots had also become more like the donor forests and less like recipient site controls. Only the unplanted gravel pit-site increased in non-native ruderal plant species after topsoil transfer. The addition of WD, shrub plantings, or SS had no significant effect after two growing seasons. We recommend that topsoil should when possible be added where trees have already been planted, allowing for shorter time to canopy closure and thereby higher survival of shade-adapted understory species.     

Restoring Caribbean Dry Forests: Evaluation of Tree Propagation Techniques

Survival and height growth of tree seedlings and rooted cuttings introduced into artificially shaded and unshaded plots in a degraded dry forest were measured at intervals for nine months. Ten tree species were selected to represent a range of ecological characteristics of the dry–forest plant community on St. John, U.S. Virgin Islands. Of three propagule types – seeds, seedlings, and rooted cuttings – introduced to field plots, seedlings survived best (52%) over the initial nine-month period. Cuttings of six species rooted successfully in a shadehouse, but only two of these species survived the nine–month field experiment. Seed germination was low, under 11% for eight of ten species tested, and four species did not germinate. Subsequent mortality of seedling recruits was moderately high. Plumeria alba was the only species for which seedling height growth was not significantly greater than cutting height growth. Shading treatment (25% of full sun) significantly increased seedling survivorship (p= 0.03) but suppressed growth slightly for some species. Shading enhanced survival of seedlings produced from broadcast seeds, but not seed germination. Mortality occurred during dry periods, apparently from drought stress. Results suggest (1) that seedling introductions are the preferred propagule type (over seeding or rooted cuttings) for ecological restoration of degraded tropical dry forests, and (2) that some level of shading is required to increase the survivorship of many dry-forest species or to avert complete mortality of some species. This study suggests that early secondary dry forest may be best restored by underplanting within the existing vegetation. Sufficient shading suitable for growth of native dry-forest trees may be attained using a nurse crop of fast-growing leguminous trees.     

Effects of Connectivity and Regional Dynamics on Restoration of Small Mammal Communities in Midwestern Grasslands

Grasslands are among the most imperiled North American ecosystems. State Acres for Wildlife Enhancement (SAFE) is a national conservation program that converts agricultural fields into grasslands mainly to improve habitat for high priority wildlife species. To provide a broader assessment of the contribution of the SAFE program to biodiversity in the Midwest region of North America, we evaluated local and landscape constraints to restoration of small mammal communities. We livetrapped small mammals during three summers (2009–2011) on plots that were recently seeded, seeded 1–4 years prior to sampling, or established references (>10 years old). Restoration trajectories for small mammal communities included a shift over time from dominance by the habitat generalist Peromyscus maniculatus (deer mouse) to communities dominated by grassland Microtus species (prairie voles and meadow voles). Vole abundance during the first year following restoration depended on spatial connectivity provided by linear habitats (roadside ditches and grass waterways) within 300 m of the restored grassland. Patch size and seeding type (cool‐season versus warm‐season grasses) were not predictors of early restoration success. In 2011, voles experienced a severe regional decline consistent with multi‐year population cycles. During the crash, most remaining voles occurred on restored SAFE grasslands, but not on established grasslands. This surprising outcome suggests young restoration plots could function as refuges for voles during population declines in agricultural landscapes.     

Facilitation and competition influence succession in a subtropical old field

The effects of neighboring vegetation and soil fertility on the establishment, survival and growth of tree species were studied in a subtropical old-field area in south Brazil. Seed damage, germination and seedling establishment of four tree species plus growth and survival of two transplanted tree species were monitored under factorial combinations of the following treatments: (1) pioneer vegetation (presence and absence); (2) soil fertility (addition of NPK and control). Facilitation was the main process affecting plant performance. The presence of pioneer vegetation significantly improved germination, establishment, growth and survival of most study species. Around 90% of sown seeds were damaged and the removal of pioneer vegetation significantly increased seed damage for all species studied, decreased germination in three out of four species, and decreased establishment in one species. Moreover a significantly higher seedling growth rate of Inga virescens was found after the first year of the experiment in plots where vegetation was present. The presence of vegetation significantly increased seedling survival of I. virescens by protecting seedlings from leaf loss due to winter frosts. Competition was detected by the second year when a higher growth of transplanted seedlings of the species Araucaria angustifolia occurred in plots where vegetation was present and fertilizer were applied. A lower growth rate was detected in plots where vegetation was present but fertilizer was not applied. These results indicate a balance between competition for soil nutrients and protection by neighbor vegetation. Damage of seedlings by leaf cutter ants was an important barrier for plant survival. Damage occurred in 80% of the A. angustifolia seedlings and 58% of these damaged seedlings died. The presence of neighboring vegetation tended to protect seedlings from ant damage. Although competition occurred, facilitation seems to be the main process driving early successional changes in this subtropical old field. This was mainly due to the improvement of local microclimatic conditions and protection against herbivores by neighboring vegetation. Facilitation occurred during establishment and growth phases in a subtropical area that is considered a productive, low stress environment. Our results indicate that facilitation may be more frequent in productive environments than previously thought.     

Vertebrate herbivores are the main cause of seedling mortality in a logged African rainforest—implications for forest restoration

High seedling mortality can limit tropical forest regeneration after disturbance, such as selective logging. However, causes of seedling mortality are often poorly understood although this information is critical for designing appropriate restoration methods. We studied seedling mortality in a rainforest in Uganda where natural recovery has failed after selective logging carried out 40 years earlier and the sites are dominated by herbaceous vegetation. We established an experiment where seeds of 12 indigenous tree species were sown into different‐sized logging gaps in order to capture factors that cause early seedling mortality. We examined whether seedling mortality was influenced by vegetation cover (VC), vertebrate herbivores (VHs), gap size, or forest compartment and recorded causes of mortality. We found that seedling mortality was in general high but showed high tree species‐specific variation (ranging from 19 to 92% six months after emergence). VHs, particularly rodents, were the most important cause of mortality. Rotting caused mortality particularly in smaller gaps, but elephant trampling, drying, being washed away by rain and falling debris were only minor mortality causes. Dense VC was not a considerable barrier to seedling survival, but by providing shelter for rodents, it indirectly increased seedling herbivory. Our results show that high seedling mortality on logged sites can limit forest regeneration and rodents in particular can be a significant factor causing high seedling mortality.     

Invasive grass density negatively impacts chaparral seedling establishment

Type conversion from native shrubland to invasive annual grassland is on the rise due to global change factors such as prolonged drought and increasing fire frequency. Efforts to restore chaparral ecosystems are limited by current understanding of competitive interactions between shrub seedlings and invasive grasses as well as soil moisture requirements of chaparral seedlings. We set up a restoration experiment where we out-planted Adenostoma fasciculatum seedlings, manipulated invasive grass density, monitored soil moisture at two depths, and tracked seedling survival and biomass. We found that higher invasive grass cover was associated with higher rates of seedling mortality but found no difference in biomass per surviving plant. Soil moisture was higher at 15 cm under the 100% weeded treatment than the 50% weeded and control treatments during January. Lower invasive cover resulted in higher richness of annual native plant species, as plots with 100% invasive removal had higher richness than 50% removal and unplanted control plots. Future restoration efforts in the chaparral will likely be more successful in increasing initial seedling establishment if invasive grass removal is included.     

Effects of Deer Browsing, Fabric Mats, and Tree Shelters on Quercus rubra Seedlings

We examined the effects of deer browsing, fabric mats, and tree shelters on the growth and survival of Quercus rubra (northern red oak) seedlings planted as part of a reforestation project in southcentral Minnesota. Browsing by white-tailed deer occurred on 68.6% of the seedlings growing without tree shelters, whereas only 3.6% of the trees were browsed by mice or voles and 2.5% were browsed by rabbits. Fabric mats, used to control competition from herbaceous plants for roughly half of the seedlings included in the study, had a detrimental effect overall. Seedlings grown with mats had a greater frequency of deer browsing and a greater chance of dying than seedlings grown without mats. Stem height for seedlings browsed by deer was less overall than for nonbrowsed seedlings, although this pattern varied with use of fabric mats and plot location. The use of plastic tree shelters effectively prevented deer browsing and reduced the mortality rate from 34.6% to 3.2%. Our results indicate that fabric mats should not be used in restoration projects with large deer populations. They also suggest that planting seedlings away from existing forest edges and using seedling protection measures such as tree shelters will increase seedling survival and growth in future restoration projects.     

Fire and seedling population dynamics in western Oregon prairies

Abstract. Through an experiment in three prairie vegetation types in western Oregon, USA the effect of prescribed fire on the timing and rates of seedling emergence and mortality was examined. Seeds of common exotic and native prairie species were sown into burned and unburned plots in late September, 1995. Emerged seedlings were censussed the following winter, early spring and late spring. Results indicated that spring population levels could not be forecast by fall seedling flushes, as winter survival was important in seedling establishment. The bulk of emergence for all grass and annual forb species occurred in the fall, followed by low to severe winter mortality. Perennial forbs were more variable in emergence times but, once emerged, perennial forb seedlings were likely to become established. Burning caused a statistically significant increase in seedling accumulation through emergence and survival in 11 of 23 cases. Burning improved seedling winter survival for most grass and short‐lived forb species and increased emergence of perennial forb species. These patterns were most conspicuous on the two sites dominated by exotic species, where burning significantly improved the accumulation of seedlings from most native species tested. Thus, prescribed burning might be a useful restoration tool in these communities. In contrast, two of the three species increased by burning in the native bunchgrass site were exotic pest plants, suggesting that fire should be prescribed with caution.     

Recovering More than Tree Cover: Herbivores and Herbivory in a Restored Tropical Dry Forest

Intense and chronic disturbance may arrest natural succession, reduce environmental quality and lead to ecological interaction losses. Where natural succession does not occur, ecological restoration aims to accelerate this process. While plant establishment and diversity is promoted by restoration, few studies have evaluated the effect of restoration activities on ecological processes and animal diversity. This study assessed herbivory and lepidopteran diversity associated with two pioneer tree species growing in 4-year-old experimental restoration plots in a tropical dry forest at Sierra de Huautla, in Morelos, Mexico. The study was carried out during the rainy season of 2010 (July-October) in eleven 50 x 50 m plots in three different habitats: cattle-excluded, cattle-excluded with restoration plantings, and cattle grazing plots. At the beginning of the rainy season, 10 juveniles of Heliocarpus pallidus (Malvaceae) and Ipomoea pauciflora (Convolvulaceae) were selected in each plot (N = 110 trees). Herbivory was measured in 10 leaves per plant at the end of the rainy season. To evaluate richness and abundance of lepidopteran larvae, all plants were surveyed monthly. Herbivory was similar among habitats and I. pauciflora showed a higher percentage of herbivory. A total of 868 lepidopteran larvae from 65 morphospecies were recorded. The family with the highest number of morphospecies (9 sp.) was Geometridae, while the most abundant family was Saturnidae, with 427 individuals. Lepidopteran richness and abundance were significantly higher in H. pallidus than in I. pauciflora. Lepidopteran richness was significantly higher in the cattle-excluded plots, while abundance was significantly higher in the non-excluded plots. After four years of cattle exclusion and the establishment of plantings, lepidopteran richness increased 20 –fold in the excluded plots compared to the disturbed areas, whereas herbivory levels were equally high in both restored and disturbed sites. Restoration with plantings and exclusion of cattle and plantings was shown to be a successful strategy for attracting lepidopterans and cattle exclusion was the main factor explaining lepidopteran diversity.     

Restoration of Northwest Florida Sandhills Through Harvest of Invasive Pinus clausa

Across much of the southeastern U.S.A., sandhills have become dominated by hardwoods or invasive pine species following logging of Pinus palustris (longleaf pine) and fire suppression. At Eglin Air Force Base where this study was conducted, Pinus clausa (sand pine) has densely colonized most southeastern sandhill sites, suppressing groundcover vegetation. The objectives of this study were: to determine if suppressed groundcover vegetation recovers following the removal of P. clausa; to compare species composition and abundance in removal plots with that in reference, high quality sandhills; to test the assumption that recolonization by P. clausa seedlings decreases with proximity to the centers of removal plots; and to measure the survival of containerized P. palustris seedlings that were planted on P. clausa removal plots. One year post‐removal (1995), the number of plant species decreased by 50%, but then increased by 100% from 1995 to 1997, followed by a small reduction in 1998. The number of plant species was greater in reference plots than in removal plots prior to 1997. Eighty‐five percent of the original species were recorded 4 years post‐harvest in removal plots. Shrubs and large trees remained at low density after harvest. Densities of graminoids, legumes, other forbs, woody vines, and small trees increased after harvest. Plant densities of all life forms, except woody vines, were greater in reference plots than in removal plots. The density of recolonizing P. clausa seedlings 2–4 years post‐harvest significantly decreased with increasing proximity to the centers of removal plots. On average, 80% of planted P. palustris seedlings survived their first 2 years. Harvest of P. clausa followed by fire and the planting of P. palustris is a reasonably effective restoration approach in invaded sandhills. However, supplementary plantings of some herbaceous species may be necessary for full restoration.     

Impacts of cyclone Larry on the vegetation structure of timber plantations,restoration plantings and rainforest on the Atherton Tableland,Australia

Abstract We examined the impact of severe cyclone ‘Larry’ on the vegetation structure of monoculture and mixed species timber plantations, restoration plantings and reference sites in upland rainforests on the Atherton Tableland, north Queensland, Australia. Sites were initially assessed in 2000 and resurveyed in 2006, 6–8 months after the cyclone traversed the region. In both surveys, timber plantations had a relatively open canopy, grassy understorey and few shrubs or small‐sized trees; whereas restoration plantings had a relatively closed canopy, an understorey of bare ground, leaf litter and rainforest seedlings, a high density of small‐diameter trees and a moderate representation of special life forms characteristic of rainforest. Cyclone damage varied with tree size, site type, proximity to the cyclone and stem density. First, the proportion of trees that were severely damaged by the cyclone (major branches broken, stem snapped or pushed over) increased with the diameter of trees across all site types. Second, damage to larger‐sized trees (>10 cm d.b.h., >20 cm d.b.h.) was proportionally highest in monoculture plantations, intermediate in mixed species plantations and rainforest, and lowest in restoration plantings. Third, within site types, damage levels decreased with distance from the cyclone track and with stem density. There was no evidence that topographical position influenced damage levels, at least for timber plantations. We tentatively attribute the high levels of damage experienced by timber plantations to their relatively open structure and the large size of stems in plantations. Restoration plantings generally escaped severe damage by the cyclone, but their continued development towards rainforest conditions may require a coordinated monitoring and maintenance programme to address the potential threat of weed invasion.     

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.     

Germination in Baltic coastal wetland meadows: similarities and differences between vegetation and seed bank

The abundance and variety of seedlings in Baltic coastal grasslands was studied in cattle grazed and ungrazed areas in seashore and delta on the western coast of Finland. The vegetation, seed bank and environmental conditions of the same sites were also studied. Altogether 4609 seedlings were observed in 79 field plots (20 cm× 20 cm) making an average of 1458.54 seedlings/m². The majority of the seedlings were dicots (67.5%) and perennials (96.8%). Altogether 44 species and an average of 4.14 species per plot were identified as seedlings. The most abundant taxon, Carex formed 23.2% of all the seedlings observed in the field. In the delta the seedling density was two times that found at the seashore. Also, the numbers of species of seedlings per plot were significantly higher in the delta than in the seashore, but in total, more species germinated from the seashore than from the delta even though the number of plots was higher in the delta (n = 51) than in the seashore (n = 28). The numbers of species and seedlings per plot were smaller in grazed sites than in ungrazed ones similar to the pattern earlier reported concerning the mature vegetation and seed bank. The mean numbers of seedlings were the highest at lower geolittoral plots (about 20 cm elevation), where the seed bank was also densest. About 60.0% of the mature species in the plots were also detected as seedlings and 91.4% of the seedling species were found in the mature vegetation of the plots. The number of seedlings was positively correlated with the cover of mature vegetation giving support to the nurse effect theory. Seedling numbers were negatively correlated with the abundance of litter indicating that litter restricts germination because it is a mechanical barrier but also decreases the amount of light. The number of seedlings and species, both in total and per unit area, were greater in the seed bank than in the field seedling population. The seedling population was more similar to the mature vegetation than to the seed bank. This revised version was published online in August 2006 with corrections to the Cover Date.     

The Metabolism of Ethanol in Germinating Pea Seedlings

Considerable losses of ethanol occurred during the germinationof green pea seeds which could not be ascribed to losses dueto the volatility of the alcohol. Changes in the contents ofacetaldehyde, acetone, organic acids, and in the gas exchangessuggested that the alcohol was oxidatively metabolized. Feedingethanol to slices of pea cotyledon tissue also indicated ethanolconversion to acetaldehyde and the interconversion of acetaldehydeand acetone. Feeding ethanol 2:¹⁴C to the slices confirmed thatthe ethanol was metabolized, giving similar changes in the contentof carbonyl compounds and organic acids to those observed inthe intact germinating pea seedlings. Thus the endogenous ethanolwhich accumulated when pea seed imbibed water prior to germinationmay be metabolized subsequently by the germinating seedling.     

Long-term bird colonization and turnover in restored woodlands

The long-term effectiveness of restored areas for biodiversity is poorly known for the majority of restored ecosystems worldwide. We quantified temporal changes in bird occurrence in restoration plantings of different ages and geometries, and compared observed patterns with a reference dataset from woodland remnants on the same farms as our plantings. Over time, bird species richness remained unchanged in spring but exhibited modest increases in winter. We found that wider plantings supported significantly greater bird species richness in spring and winter than narrow plantings. There was no evidence of a significant interaction between planting width and time. We recorded major temporal changes in the occurrence of a range of individual species that indicated a clear turnover of species as plantings matured. Our results further revealed marked differences in individual species occurrence between plantings and woodland remnants. Life-history attributes associated with temporal changes in the bird assemblage were most apparent in winter survey data, and included diet, foraging and nesting patterns, movement behaviour (e.g. migratory vs. dispersive), and body size. Differences in bird assemblages between plantings of different ages suggest that it is important that farms support a range of age classes of planted woodland, if the aim is to maximize the number of native bird species in restored areas. Our data also suggest that changes in the bird species occupying plantings of different ages can be anticipated in a broadly predictable way based on planting geometry (especially width) and key life-history attributes, particularly movement patterns and habitat and diet specialisation.     

Ecological Assessment of Dune Restorations in the Great Lakes Region

Because of the economic and environmental importance of stabilizing fragile sand dune habitats, restoration of dunes has become a common practice. Restoration efforts in the Great Lakes and East Coast regions of North America often consist of planting monocultures of the dominant native grass species, Ammophila breviligulata. We evaluated 18 dune restoration projects in the Great Lakes region conducted over the past 25 years. We characterized attributes of diversity (plants and insects), vegetation structure (plant biomass and cover), and ecological processes (soil nutrients and mycorrhizal fungi abundance) in each restoration, and we compared these measures to geographically paired natural dune communities. Restoration sites were similar to reference sites in most measured variables. Differences between restorations and reference sites were mostly explained by differences in ages, with the younger sites supporting slightly lower plant diversity and mycorrhizal spore abundance than older sites. Plant community composition varied little between restored and reference sites, with only one native forb species, Artemisia campestris, occurring significantly more often in reference sites than restored sites. Although it remains unclear whether more diverse restoration plantings could accelerate convergence on the ecological conditions of reference dunes, in general, traditional restoration efforts involving monoculture plantings of A. breviligulata in Great Lakes sand dunes appear to achieve ecological conditions found in reference dunes.