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1.
Plantations are frequently established on abandoned pasture lands to speed forest recovery. This strategy requires matching a tree species mix with the prevailing microenvironmental conditions. In four degraded pastures of the Mexican Lacandon rainforest, we planted 2,400 trees of 6 species (Guazuma ulmifolia, Inga vera, Ochroma pyramidale, Trichospermum mexicanum, Bursera simaruba, and Spondias mombin) to (1) test survival, initial growth, and establishment costs; (2) evaluate whether vegetative cuttings outperform direct seeding or transplants of nursery‐raised seedlings; (3) determine tree response to herbaceous dominance and soil compaction; and (4) scrutinize the results' consistency across sites and sampling scales of tree–microenvironment interactions (individual tree vs. averaged plot responses). After 2 years, overall survival and growth rates were high for 2 of 3 nursery‐raised species. Contrary to expectations, all seedlings outperformed the cuttings while direct seeding resulted in a cost‐effective option of intermediate efficacy. The impact of soil resistance to root penetration on tree biomass accumulation was species dependent while bulk density was not relevant. Soil‐covering, herbaceous vegetation accelerated growth in 3 of 4 tested species during the dry season. At this initial stage of forest restoration in abandoned pastures, Guazuma and Trichospermum were the most restoration‐effective species. Costs can be reduced by using direct‐seeding Inga and avoiding weeding during the dry season. Finally, our results demonstrate how species selection trials can be misleading due to site variations in tree response and to sampling scales that fail to account for small‐scale environmental heterogeneity. We recommend ways to improve the design of restoration trials.  相似文献   

2.
Outplanting container-grown oak seedlings with undesirable shoot and root characteristics result in poor establishment and reduced field growth. The objective of this study was to determine the influence of container type on both above-and below-ground nursery growth and field performance of one-year old tap-rooted seedlings Quercus ilex L. and Quercus coccifera L. The experiment was conducted in an open-air nursery and the seedlings were grown in three container types. At the end of the nursery, growth period seedlings’ shoot height, diameter (5 mm above root collar), shoot and root biomass, root surface area, root volume and total root length were assessed. Then the seedlings were planted in the field and their survival and growth were recorded for two growing seasons after outplanting. The results showed a difference between the Quercus species in the effect of container type. Q. ilex seedlings raised in paper-pot had significantly greater height, diameter, shoot and root biomass and root volume than those raised in the other two container types. Similarly, Q. coccifera seedlings raised in paper-pot, had significantly greater above-and below-ground growth than those raised in the other two container types. Both oak species showed relatively low survival in the field; the mortality was mainly observed the first year after outplanting, especially after the summer dry period. However, 2 years after outplanting, the paper-pot seedlings of the two oak species showed better field performance.  相似文献   

3.
Fig (Ficus spp.) trees have been promoted as framework species for tropical forest restoration throughout Asia, because they are considered to be keystone species. This article presents optimal propagation and planting techniques for six Asian dioecious Ficus species, which will enable their inclusion in forest restoration plantings across the Asia‐Pacific region: Ficus auriculata, F. fulva, F. hispida, F. oligodon, F. semicordata, and F. variegata. Nursery experiments compared the growth performance of propagating planting stock from seed and from leafy cuttings, whereas field experiments assessed the cost‐effectiveness and the relative performance of (1) direct seeding, (2) planting stock from seed, and (3) planting stock from cuttings. The most efficient method of producing Ficus spp. was from seed. Propagation from cuttings was much less successful. Seedlings produced from seed had the highest rates of growth and survival both in the nursery and in field trials. In field trials, use of planting stock from seed was also more cost‐effective than direct seeding and vegetative propagation. Establishment costs calculated on the basis of “per plant established” were $1.14 for seed, $6.95 for cutting, and $25.88 for direct seeding.  相似文献   

4.
Direct seeding is one of the most feasible techniques in practical, logistical, and economic terms for large-scale restoration of arid lands. However, several factors are still under study to enhance the outcomes of this restoration alternative, with species selection being a pivotal component. To evaluate differences in the performance of species in direct seeding, we selected five shrubs from the arid region known as “Monte Desert” in Argentina: Atriplex lampa, Hyalis argentea, Larrea divaricata, Neltuma flexuosa var. depressa, and Parkinsonia praecox. Direct seeding was carried out in furrows (4.0 m long, 0.5 m wide, and 0.4 m deep) with seeds previously treated to dormancy alleviation and with a density of 250 seeds/m2. We evaluated results in 12 furrows, where topsoil and hydrogel were deposited. The biological variables considered were seedling emergence, seedlings establishment regarding sowed seeds, and seedling success (survival in relation to emerged seedlings) after almost 3 years. The species with the highest emergence and establishment rates was A. lampa (50.16 and 23.75%, respectively). L. divaricata showed the lowest values for these variables (2.17 and 0.83%, respectively). On the other hand, the survival of N. flexuosa seedlings was >2× that of L. divaricata (65.02 vs. 30.36%). We discuss the notable differences in species performance and the possible role of furrows in the results.  相似文献   

5.
Coral nursery and outplanting practices have grown in popularity worldwide for targeted restoration of degraded “high value” reef sites, and recovery of threatened taxa. Success of these practices is commonly gauged from coral propagule growth and survival, which fundamentally determines the return‐on‐effort (RRE) critical to the cost‐effectiveness and viability of restoration programs. In many cases, RRE has been optimized from past successes and failures, which therefore presents a major challenge for locations such as the Great Barrier Reef (GBR) where no local history of restoration exists to guide best practice. In establishing the first multi‐taxa coral nursery on the GBR (Opal Reef, February 2018), we constructed a novel scoring criterion from concurrent measurements of growth and survivorship to guide our relative RRE, including nursery propagule numbers (stock density). We initially retrieved RRE scores from a database of global restoration efforts to date (n = 246; 52 studies) to evaluate whether and how success commonly varied among coral taxa. We then retrieved RRE scores for Opal Reef using initial growth and survivorship data for six key coral taxa, to demonstrate that RRE scores were high for all taxa predominantly via high survivorship over winter. Repeated RRE scoring in summer is therefore needed to capture the full dynamic range of success where seasonal factors regulating growth versus survivorship differ. We discuss how RRE scoring can be easily adopted across restoration practices globally to standardize and benchmark success, but also as a tool to aid decision‐making in optimizing future propagation (and outplanting) efforts.  相似文献   

6.
Inoculation with beneficial soil microorganisms has the potential to enhance success of restoration, particularly in harsh Mediterranean‐type ecosystems (MTEs). We investigated the effects of microorganisms (mycorrhizal fungi and root nodule bacteria) and planting material (seed and nursery‐raised seedlings) on early establishment and growth of two key postdisturbance colonizing species with different life histories, life forms and functional types (Eucalyptus gomphocephala and Acacia saligna) under field conditions. Establishment and growth were monitored at 13 months, following the first MTE drought period. For E. gomphocephala, establishment was higher for seedlings (81%) than for seeding (7.5%). Inoculation with ectomycorrhizal fungal spores was not beneficial. For A. saligna, establishment was also higher for seedlings (84%) than for seeding (42.5%). Mycorrhizal fungal inoculum had no effect on establishment or growth. This study has shown that in harsh MTE conditions, the use of seedlings is more effective than seeding in degraded woodlands even when attempting to reintroduce key colonizing species. The microorganism treatments tested did not result in significant improvement in establishment or growth.  相似文献   

7.
Direct seeding is a promising method for reducing restoration costs, but methodological adjustments are still needed to reduce the uncertainties to achieve a desired seedling density in the field. Here, we investigated the technical approaches and outcomes of direct seeding of fast‐growing native trees for cost‐effective restoration of the Brazilian Atlantic Forest. Sixteen tree species were manually sown at three seeding densities in planting lines prepared with a subsoiler, in two experimental areas, which were weeded with hoes and had leaf‐cutter ants controlled with insecticide baits. Seedling density was monitored for 30, 90, and 180 days after sowing. No substantial change in tree density was observed 30 days after sowing, thus allowing fast corrective actions to adjust tree density. Only a minor proportion of the sown viable seeds resulted in established seedlings at 180 days (4–12% for the community; approximately 25% for the species with the best performance). However, tree density was high (6,000 on average; approximately 1,400–13,000 trees/ha) and allowed an effective canopy development. Overall, seedling density was linearly and positively associated with seeding density, was highly influenced by the species used, and was higher in the soil with higher sum of bases. Buying seeds would be, for most species, less costly than buying nursery‐grown seedlings for achieving the expected tree densities in the field. These results evidence the potential of direct seeding for reducing restoration costs, as well as the need to select species with better performance and adjust seeding densities to optimize the use of this method.  相似文献   

8.
A priority in restoration research is to seek methods that reach high levels of plant establishment at the lowest possible cost. Here, we test how direct seeding works with and without a plastic protector that covers seeds and seedlings in an early‐successional rainforest in Veracruz (Mexico). Two native species, Calophyllum brasiliense (barí) and Vochysia guatemalensis (corpo), at three topographic positions, were used. Germination rates with and without the protector were 84 versus 79% for C. brasiliense, and 98 versus 89% for V. guatemalensis, respectively. The protector significantly improved the germination only of V. guatemalensis. Plant survivorship of V. guatemalensis 27 months after seeding was significantly higher with the protector (78%) than without it (46%). For C. brasiliense, there were no differences in survivorship after 22 months with (61%) and without (54%) protector. In both species, the protector had no effect on height growth, which was significantly larger for seedlings located at the toeslope position. We developed a cost–benefit model that provides a threshold value at which the investment for protectors is justified by a resulting higher survivorship: If 27 months after seeding a treelet of V. guatemalensis is worth at least 0.83 USD on our sites, then the effect of the protector is worth the cost of its implementation (for C. brasiliense, survivorship was statistically undistinguishable with and without protector). We suggest that direct seeding with a plastic protector could be a promising alternative for forest restoration with suitable tree species.  相似文献   

9.
 Experimental plantations were established in northern Spain to determine the effects of different ectomycorrhizal fungi on growth and survival of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) under field conditions. Douglas-fir seedlings were inoculated with Laccaria bicolor S238 mycelia in two bareroot nurseries in central France or with spore suspensions of three hypogeous ectomycorrhizal species: Melanogaster ambiguus, Rhizopogon colossus and R. subareolatus, in a Spanish containerised nursery. The effects of ectomycorrhizal inoculation on plant survival after outplanting were limited, being only significant at the Guipuzkoan (Spain) site, when plants inoculated with L. bicolor S238 were compared to non-inoculated plants grown in non-fumigated soil. L. bicolor S238 had a significant effect on plant growth during the phase of bareroot nursery growth and this difference was maintained after field outplanting. Nursery inoculations with M. ambiguus, R. colossus and R. subareolatus improved plant growth during the first 2 and 3 years after field outplanting. The positive effects of the inoculation treatment on seedling height, root collar diameter and stem volume persisted after 5 years of field growth. Inoculation with these ectomycorrhizal fungi may improve the field performance of Douglas-fir seedlings in northern Spain. Accepted: 12 February 1999  相似文献   

10.
In recent decades, the Florida reef tract has lost over 95% of its coral cover. Although isolated coral assemblages persist, coral restoration programs are attempting to recover local coral populations. Listed as threatened under the Endangered Species Act, Acropora cervicornis is the most widely targeted coral species for restoration in Florida. Yet strategies are still maturing to enhance the survival of nursery‐reared outplants of A. cervicornis colonies on natural reefs. This study examined the survival of 22,634 A. cervicornis colonies raised in nurseries along the Florida reef tract and outplanted to six reef habitats in seven geographical subregions between 2012 and 2018. A Cox proportional hazards regression was used within a Bayesian framework to examine the effects of seven variables: (1) coral‐colony size at outplanting, (2) coral‐colony attachment method, (3) genotypic diversity of outplanted A. cervicornis clusters, (4) reef habitat, (5) geographical subregion, (6) latitude, and (7) the year of monitoring. The best models included coral‐colony size at outplanting, reef habitat, geographical subregion, and the year of monitoring. Survival was highest when colonies were larger than 15 cm (total linear extension), when outplanted to back‐reef and fore‐reef habitats, and when outplanted in Biscayne Bay and Broward–Miami subregions, in the higher latitudes of the Florida reef tract. This study points to several variables that influence the survival of outplanted A. cervicornis colonies and highlights a need to refine restoration strategies to help restore their population along the Florida reef tract.  相似文献   

11.
Recent declines in coral populations along the Florida reef tract have prompted the establishment of coral restoration programs which raise coral species, such as the threatened Acropora cervicornis, in nurseries ready for outplanting. Large numbers of nursery‐reared coral colonies have been outplanted along the Florida reef tract in recent years, yet few studies have characterized benthic habitats that are considered optimal for colony survival. In 2016, we surveyed 23 A. cervicornis restoration sites, located at six different reefs in the upper Florida Keys. We examined the condition of the outplanted corals and quantified the benthic assemblages adjacent to the outplanted coral colonies. We found that where A. cervicornis survived for more than 1 year, the substrate significantly supported less brown macroalgae of the genus Dictyota than at sites where A. cervicornis had died. Coral survival was highest at sites with less than 15% Dictyota cover. These results suggest that the habitat conditions that supported Dictyota spp. were not conducive to A. cervicornis growth and survival. Restoration practitioners should avoid attaching nursery‐raised corals to substrate with Dictyota spp. cover greater than 15%.  相似文献   

12.
Though translocations of rare populations should be considered only as the last resort for species’ conservation, when habitat destruction is imminent, it may be the only means to preserve a species. With over half the known, wild federally endangered Crenulate leadplant (Amorpha herbacea var. crenulata), Fabaceae, growing on unprotected land slated for development, preserving this unprotected population was critical. We rescued whole plants, cuttings, and seeds for an experimental translocation. Into a restored pine rockland, once dominated by the invasive exotic tree Brazilian pepper (Schinus terebinthifolius), we transplanted plants from different sources and of different sizes. Plants used were rescued from an unprotected site, seedlings, and 1‐, 2‐, and 7‐year‐old plants from Fairchild Tropical Botanic Garden’s ex situ collection, creating a novel population in a new habitat. We also evaluated which propagule type and source had the best survival, growth, and reproduction. After 40 months, overall transplant survival was 71%. Large whole plants, rescued and nursery grown, had the best survival rates (86 and 78%), whereas cuttings had 67% survival and seedlings had only 26% survival. The restored site, once nearly a monoculture of S. terebinthifolius, is now dominated by 104 native plant species, including 17 naturally recruited state listed, plus the one translocated federally endangered plant species. In addition, one federally threatened snake species was observed on the site. These studies demonstrate that botanic garden collections not only play a vital role in the conservation of species’ genetic diversity but also can be used as source material for habitat restoration.  相似文献   

13.
Deforestation in the Amazon Basin is still increasing, and the rehabilitation of these lands continues to be a challenge. Autoecological studies of most Amazonian species are rare, and efficient techniques for restoration of forested habitats have yet to be developed. The aim of this study was to test direct sowing as a rehabilitation technique for sites with different degrees of disturbance: bare soil, pasture, and secondary and mature forests in Central Amazonia, Brazil. At each site, we sowed seeds of 11 native tree species. Throughout the following year we evaluated germination and seedling survival. The germination differed according to the study site and species. Seedling survival in degraded sites was higher than in other areas. After 1 year in the bare soil site, 33% of the sown seeds of eight species developed seedlings; in the pasture the establishment was 23%, in secondary forest 15%, and in mature forest 12% of only four species. The only widespread survivor with more than 45% emergence in all perturbed sites was Caryocar villosum. No pioneer seedlings remained after 1 year. There was a positive correlation between seed size and survival. Large‐seeded non‐pioneer species seem to be more suitable for direct sowing than small‐seeded species. We recommend a combination of direct sowing and planting of seedlings as an appropriate means to accelerate the rehabilitation of degraded areas in Central Amazonia.  相似文献   

14.
Direct seeding is a promising technique for ecological restoration, but it has been poorly studied in neotropical savannas. Different types of plant cover (no cover, crops, or green manure) and fertilization (unfertilized, synthetic fertilizer, or poultry litter) were used to verify if survival and growth of different tree species after direct seeding could be enhanced by the use of any combination of these techniques. Seedling emergence, establishment, and growth were followed for 2 years for six savanna tree species sown in an agricultural field in Central Brazil. Germination was high (52%, on average) for Anacardium occidentale, Aspidosperma macrocarpon, Hymenaea stigonocarpa, Dipteryx alata, Eugenia dysenterica, and Magonia pubescens. Six additional species were planted, but less than 5% of these seeds germinated. Crops (60% shade) did not affect seedling survival and biomass compared with the control treatment, supporting the use of this strategy during the initial phase of restoration to involve farmers in the process. In contrast, the excessive shading (95%) from the green manure treatment decreased the survival of two species and the growth in biomass and diameter of five species, especially when combined with fertilization. Seedling growth was very slow throughout the experiment, requiring extended weed management. This study supports the use of direct seeding of the studied species for savanna restoration, but methods could be improved to include a larger number of species.  相似文献   

15.
The survival, development and mycorrhizal efficiency of a selected strain of Laccaria bicolor along with naturally occurring ectomycorrhizal fungi in a young plantation of Douglas fir was examined. Symbionts were identified and their respective colonization abilities were determined. Eight species of symbiotic fungi, which may have originated in adjacent coniferous forests, were observed on the root systems. Mycorrhizal diversity differed between inoculated (5 taxa) and control (8 taxa) seedlings. Ectomycorrhizal fungi which occurred naturally in the nursery on control seedlings (Thelephora terrestris and Suillus sp.) did not survive after outplanting. Both inoculated and naturally occurring Laccaria species, as well as Cenococcum geophilum, survived on the old roots and colonized the newly formed roots, limiting the colonization by other naturally occurring fungi. Other fungi, such as Paxillus involutus, Scleroderma citrinum and Hebeloma sp. preferentially colonized the old roots near the seedling's collar. Russulaceae were found mainly in the middle section of the root system. Mycorrhizal colonization by Laccaria species on inoculated seedlings (54%) was significantly greater than on controls (13%) which were consequently dominated by the native fungi. Significant differences (up to 239%) were found in the growth of inoculated seedlings, especially in root and shoot weight, which developed mainly during the second year after outplanting. Seedling growth varied with the species of mycorrhizae and with the degree of root colonization. Competitiveness and effectiveness of the introduced strain on improving growth performances of seedlings are discussed.  相似文献   

16.
The methods used to distribute seeds influence the success of a restoration project. We surveyed 183 restoration practitioners from across the globe with the aim of identifying common limitations to the effective use of mechanical direct seeding in large‐scale restoration practice to highlight avenues for design improvement to mechanized seeding equipment. Results from this survey show that direct seeding methods are commonly used for ecological restoration and agree with other studies that suggest the method can achieve results much quicker and cheaper than the alternative of distributing nursery‐grown tube stock. However, this study indicates that current mechanical direct seeding methods lack adequate control of seed sowing depth and spatial distribution and highlight that the inability to sow seeds of varying morphology over complex topography are common limitations to direct seeding. To improve restoration success, engineering improvements to mechanical direct seeders used in large‐scale restoration should focus in particular on addressing issues of precision of delivery for diverse seed types and landscapes.  相似文献   

17.
Mycorrhizas on nursery and field seedlings of Quercus garryana   总被引:1,自引:0,他引:1  
Oak woodland regeneration and restoration requires that seedlings develop mycorrhizas, yet the need for this mutualistic association is often overlooked. In this study, we asked whether Quercus garryana seedlings in nursery beds acquire mycorrhizas without artificial inoculation or access to a mycorrhizal network of other ectomycorrhizal hosts. We also assessed the relationship between mycorrhizal infection and seedling growth in a nursery. Further, we compared the mycorrhizal assemblage of oak nursery seedlings to that of conifer seedlings in the nursery and to that of oak seedlings in nearby oak woodlands. Seedlings were excavated and the roots washed and examined microscopically. Mycorrhizas were identified by DNA sequences of the internal transcribed spacer region and by morphotype. On oak nursery seedlings, predominant mycorrhizas were species of Laccaria and Tuber with single occurrences of Entoloma and Peziza. In adjacent beds, seedlings of Pseudotsuga menziesii were mycorrhizal with Hysterangium and a different species of Laccaria; seedlings of Pinus monticola were mycorrhizal with Geneabea, Tarzetta, and Thelephora. Height of Q. garryana seedlings correlated with root biomass and mycorrhizal abundance. Total mycorrhizal abundance and abundance of Laccaria mycorrhizas significantly predicted seedling height in the nursery. Native oak seedlings from nearby Q. garryana woodlands were mycorrhizal with 13 fungal symbionts, none of which occurred on the nursery seedlings. These results demonstrate the value of mycorrhizas to the growth of oak seedlings. Although seedlings in nursery beds developed mycorrhizas without intentional inoculation, their mycorrhizas differed from and were less species rich than those on native seedlings.  相似文献   

18.
Fire is the most important disturbance factor in Cypress (Austrocedrus chilensis) forests in Patagonia, Argentina. This ecosystem recovers poorly after fire, and direct sowing could be a potentially useful restoration practice. To evaluate the effect of season of sowing, post‐fire plant cover (PC), and climatic variability on seedling emergence and survival, three direct sowing studies were established in two burned cypress stands: Trevelin (xeric conditions) and El Bolsón (mesic conditions). Two studies were conducted in winter (2000 and 2001) and one in spring (2001). Precipitation was higher than the mean during the 2000–2001 growing season and lower during 2001–2002. At both sites, emergence and survival were much higher for winter‐ than for spring‐sown seedlings. In the xeric stand, emergence and survival of winter‐sown seedlings increased with medium and high PC values, after the humid and dry summers, respectively. However, most spring‐sown seedlings did not emerge, and those that did were short‐lived. Because of the more favorable growing conditions in the mesic stand, PC had no effect on emergence and only favored first year survival of winter‐sown seedlings after the dry summer. Spring‐sown seedlings showed no association with PC in the mesic site, probably because the first summer was exceptionally humid. We speculate that shading plants exert a positive effect on cypress seedling establishment, likely by reducing the stress from high temperatures and low water availability. Sowing of small patches under the protection of understory vegetation could be useful in restoring burned cypress stands.  相似文献   

19.
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.  相似文献   

20.
The goal of restoration is to accelerate ecosystem recovery, but in ecosystems that naturally regenerate rapidly restoration techniques need to be selected carefully to facilitate rather than impede natural recovery. We compared the effects of five restoration techniques, such as plowing the soil, removing grasses, adding forest litter, seeding, and planting nursery‐growing seedlings, on the regeneration of seasonal deciduous forest trees in four abandoned pastures in central Brazil. We monitored all woody stems immediately prior to treatments and again 14 months after the treatments. We recorded an average of 16,663 tree stems per hectare and a total of 83 species before implementing treatments. Planting strongly increased species richness; adding litter and seeding had weaker positive effects on richness; and plowing and grass removal had no effect. Plowing substantially reduced the density of naturally established stems. Despite the high survival of planted seedlings, stem density in planting treatments did not change because the tractor and digging holes to plant seedlings caused mortality of naturally regenerating seedlings. Tree stems grew more in the grass release plots than in the control plots. Our results suggest that early succession of seasonal deciduous forest in pastures in the region studied does not need to be stimulated once the perturbation is stopped and that intensive restoration efforts may actually slow recovery. We recommend only enrichment planting of seedlings that are not able to resprout.  相似文献   

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