Tree Seedling Survival Depends on Canopy Age, Cover and Initial Composition: Trade-offs in Forest Restoration Enrichment Planting

2018 ◽  
Vol 36 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Daniel C. Laughlin ◽  
Bruce D. Clarkson
Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1381
Author(s):  
Danilo Simões ◽  
Jean Fernando Silva Gil ◽  
Richardson Barbosa Gomes da Silva ◽  
Rafaele Almeida Munis ◽  
Magali Ribeiro da Silva

Background: Experts in ecological restoration have discussed the cost reduction to make forest restoration financially feasible. This is very important in developing countries, such as Brazil, and for smallholder farmers; however, economic studies do not usually consider the uncertainties in their analysis. Therefore, this study aimed to analyze, under conditions of uncertainty, how tropical tree seedlings produced in polyethylene bags, polyethylene tubes, and biodegradable containers (Ellepot®) interfere with the costs of implementation and post-planting maintenance investment projects in a deforested tropical seasonal forest area in southern Brazil. Methods: We evaluated total costs, production costs, and equivalent annual uniform costs, and the probability distributions and estimated ranges of stochastic values were adjusted through Monte Carlo method simulation. Furthermore, the seedling survival rate was recorded over 12 months post-planting. Results: The costs with tree seedling acquisition and direct labor were the components that most impacted total costs in the three investment projects. The forest restoration investment project with tree seedlings produced in polyethylene bags was economically unfeasible in relation to other projects. Conclusions: The best economic alternative was observed in the investment project with tree seedlings produced in Ellepot®, which showed a survival rate >80% after one year and the lowest total cost, production cost, and equivalent uniform annual cost.


2021 ◽  
Vol 9 ◽  
Author(s):  
João Costa e Silva ◽  
Rebecca Jordan ◽  
Brad M. Potts ◽  
Elizabeth Pinkard ◽  
Suzanne M. Prober

We evaluated population differences and drought-induced phenotypic selection on four seedling traits of the Australian forest tree Eucalyptus pauciflora using a glasshouse dry-down experiment. We compared dry and mesic populations and tested for directional selection on lamina length (reflecting leaf size), leaf shape, the node of ontogenetic transition to the petiolate leaf (reflecting the loss of vegetative juvenility), and lignotuber size (reflecting a recovery trait). On average, the dry population had smaller and broader leaves, greater retention of the juvenile leaf state and larger lignotubers than the mesic population, but the populations did not differ in seedling survival. While there was statistical support for directional selection acting on the focal traits in one or other population, and for differences between populations in selection gradient estimates for two traits, only one trait—lamina length—exhibited a pattern of directional selection consistent with the observed population differences being a result of past adaptation to reduce seedling susceptibility to acute drought. The observed directional selection for lamina length in the mesic population suggests that future increases in drought risk in the wild will shift the mean of the mesic population toward that of the dry population. Further, we provide evidence suggesting an early age trade-off between drought damage and recovery traits, with phenotypes which develop larger lignotubers early being more susceptible to drought death. Such trade-offs could have contributed to the absence of population mean differences in survival, despite marked differentiation in seedling traits.


Data in Brief ◽  
2021 ◽  
pp. 107073
Author(s):  
Christine Magaju ◽  
Leigh Ann Winowiecki ◽  
Pietro Bartolini ◽  
Asma Jeitani ◽  
Ibrahim Ochenje ◽  
...  

2019 ◽  
Vol 35 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Hamza Issifu ◽  
George K. D. Ametsitsi ◽  
Lana J. de Vries ◽  
Gloria Djaney Djagbletey ◽  
Stephen Adu-Bredu ◽  
...  

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.


2008 ◽  
Vol 25 (3) ◽  
pp. 117-123 ◽  
Author(s):  
William S. Keeton

Abstract Riparian forest restoration can be severely constrained by tree seedling mortality. I evaluated the effects of tree shelters and planting density on herbivory and seedling mortality at a restoration site in the Lake Champlain Basin of Vermont. Eighteen experimental units were established along a 5th-order stream and planted with bare-root seedlings of seven species associated with northern hardwood floodplain forests. Two treatments were applied in a factorial design: shelters versus no shelters and high versus low planting density. Mortality and herbivory data were collected over three growing seasons. Survivorship declined to 56.4% after three growing seasons and varied significantly by species. Planting density, presence/absence of shelters, and their interaction had significant effects on survival, browse, or girdling intensity when tested for all species combined. Browse rates were high (44%), whereas girdling rates were low (3.4%). Both browse (P < 0.001) and girdling (P = 0.022) contributed to seedling mortality. High rates of deer browse on seedlings in shelters were due, in part, to the short height (60 cm) of the shelters, suggesting a need for taller shelters. A large portion (39%) of dead seedlings were neither browsed nor girdled, signaling the importance of other mortality agents. An adaptive approach is recommended to compensate for high seedling mortality and the limited effectiveness of protective devices.


2014 ◽  
Vol 90 (3) ◽  
pp. 313
Author(s):  
CLAUDIA ALVAREZ-AQUINO ◽  
GUADALUPE WILLIAMS-LINERA

La restauración del bosque tropical seco es prioritaria por ser el bosque más amenazado. En Veracruz, el bosque seco se ha reducido al 7% de su cobertura original. Nuestro objetivo fue determinar el efecto de la condición del sitio a restaurar y la estacionalidad en la supervivencia y tasa de crecimiento relativo en altura y diámetro de especies de árboles nativos. Estudiamos el desempeño de plántulas durante dos estaciones secas y dos lluviosas, y el efecto de la vegetación leñosa existente &gt; 1 m de altura. Se trasplantaron 960 plantas: 40 individuos de seis especie (Cedrela odorata, Ceiba aesculifolia, Guazuma ulmifolia, Ipomoea wolcottiana, Luehea candida, Tabebuia rosea) en cuatro sitios abandonados. La supervivencia y la tasa de crecimiento relativo se registraron cada cuatro meses durante dos años. La mayor supervivencia se observó en sitios con mayor riqueza de especies arbóreas y la tasa de crecimiento relativo en altura estuvo positivamente correlacionada con la altura de la vegetación existente. La mayor tasa de crecimiento relativo para especies y sitios se registró durante la estación lluviosa. En el sitio con menos vegetación, el desempeño de las plántulas fue pobre y sólo Guazuma sobrevivió. Ceiba mostró la mayor supervivencia (82-90%) pero una tasa de crecimiento relativo baja; Guazuma presentó una supervivencia elevada (20-94%) y la mayor tasa de crecimiento relativo; Cedrela mostró la menor supervivencia (3-7%) y tasa de crecimiento relativo alta. Los resultados sugieren que la vegetación del sitio, la estacionalidad y las especies afectan el desempeño de las plántulas durante el establecimiento temprano. La implicación en términos de la restauración ecológica es la importancia de aprovechar la vegetación existente aunque ésta sea escasa.


Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 74 ◽  
Author(s):  
Jorge Castro ◽  
Alexandro Leverkus

Herbaceous vegetation is a major source of interference with the regeneration of woody species. This is particularly the case after forest fires, as a dense herbaceous layer usually regenerates naturally. Although the competitive effect of the herbaceous vegetation upon tree seedlings has been widely studied, there are still gaps in knowledge for management related to the effect of tree seedling age and size on the outcome of the interaction. In this study, we seek to determine the response of maritime pine (Pinus pinaster Aiton) seedlings to herbaceous competition at two different seedling ages. For that, two treatments of herbaceous competition were implemented, namely unweeded (no action around pine seedlings) and weeded (herbaceous cover removed around pine seedlings). Treatments were conducted twice (2 and 4 years after the fire), and we monitored seedling survival and growth at the end of each growing season. The treatments were implemented across three adjacent landscape units that differed in the management of burned wood and that are representative of common post-fire scenarios: no intervention, salvage logging, and an intermediate degree of intervention. Weeding increased seedling survival from 44.7% to 67.8% when seedlings were 2 years old, but had no effect for four-year-old seedlings, which showed 99% survival. Seedling growth also increased in the weeding treatment, but only slightly. Moreover, growth (and survival for two-year-old seedlings) was strongly correlated with initial seedling size, particularly in the case of two-year-old seedlings. Initial pine seedling height was strongly and positively correlated with the height of the herbaceous layer, supporting the existence of microsite features that promote plant growth above competitive effects. The results support that management actions conducive to foster post-fire pine forest restoration in this Mediterranean ecosystem should reduce herbaceous competition at early stages after fire (second or third year) and focus on larger seedlings.


Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1124
Author(s):  
Douglass F. Jacobs ◽  
Anthony S. Davis ◽  
R. Kasten Dumroese ◽  
Owen T. Burney

Anthropogenic activity has caused persistent and prominent losses of forest cover in dry tropical forests. Natural regeneration of forest trees in grazed areas often fails due to lack of seed sources and consumption by ungulates. To address this, the effective restoration of such sites often requires fencing and outplanting nursery-grown seedlings. In the degraded, dry forests of tropical Hawaii, USA, an additional challenge to restoration of native forest trees is the introduced kikuyu grass (Cenchrus clandestinus). This invasive, rapidly growing rhizomatous plant forms deep, dense mats. We studied the use of nursery cultural techniques to facilitate the establishment of koa (Acacia koa) seedlings outplanted amidst well-established kikuyu grass on a volcanic cinder cone on the dry, western side of Hawaii Island. Seedlings were grown four months in three container sizes (49, 164, 656 cm3) and with four rates (0, 4.8, 7.2, and 9.6 kg m−3) of 15–9–12 (NPK) controlled-release fertilizer incorporated into media prior to sowing. After 16 months in the field, seedling survival was > 80% for all treatments with two exceptions: the non-fertilized 49 cm3 (78%) and 164 cm3 (24%) containers. After 10 years, only these two treatments had significantly lower survival (35% and 10%, respectively) than the other treatments. One year following planting, none of the non-fertilized seedlings had transitioned to phyllodes from juvenile true leaves, regardless of container size. For the fertilized 656 cm3 container treatment, 78%–85% of seedlings had phyllodes, with mean values increasing by fertilizer rate. Phyllodes are known to confer greater drought resistance than true leaves in koa, which may help to explain the improved survival of fertilized trees on this relatively dry site. Overall, nursery fertilization was more influential on seedling height and diameter response than container size after outplanting. However, the largest container (656 cm3) with the addition of fertilizer, produced significantly larger trees than all other treatments during the early regeneration phase; early growth differences tended to fade at 10 years due to inter-tree canopy competition. Although koa is able to fix atmospheric nitrogen through rhizobium associations, our data confirm the importance of nursery fertilization in promoting regeneration establishment. Nursery cultural techniques may play an important role in forest restoration of dry tropical sites invaded by exotic vegetation.


Author(s):  
Antonio Montagnoli ◽  
R. Kasten Dumroese ◽  
Mattia Terzaghi ◽  
Jeremiah R. Pinto ◽  
Nicoletta Fulgaro ◽  
...  

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