scholarly journals Vegetation regeneration on natural terrain landslides in Hong Kong: direct seeding of native species as a restoration tool

Author(s):  
Ying Ki Law ◽  
Calvin Lee ◽  
Chun Chiu Pang ◽  
Billy Hau ◽  
Jin Wu

Landslides are common in tropical and subtropical regions with hilly terrains and heavy rainstorms, which cause significant economic, ecological, and social impacts. Natural forest succession is usually slow on landslide scars due to poor soil structure and the lack of seeds of woody plant seeds, and often comes with a higher risk of repeated landslide. Ecological forest restoration has recently been suggested as an effective alternative to restore the exposed landslide scars, however, a comprehensive study to identify effective landslide restoration strategies remains lacking, particularly associated with seed treatment methods and species selection. Here we evaluated the effectiveness of different seed coating treatments of both pioneer and later successional tree species of different seed sizes on seed germination in a one-year study on three landslides in Hong Kong. Our results show that bare seeds had germination rates of 17 to 67% across all selected species (n=7). Biochar-dominant seed coating formulation boosted an additional 9.33 (SE= 0.04) in seed germination rate, while the clay-dominant seed coating formulation did not show significant effect on germination. Our results also show that medium and large-seeded non-pioneer species have significantly higher germination rates than pioneer species. These results collectively suggest that direct seeding using a biochar seed coat is a manageable and useful method to enhance tree seed germination—an essential first step to restore the forests after landslide disturbances in Hong Kong, with potential to be extended to other humid tropical and subtropical forests.

2019 ◽  
Vol 9 (13) ◽  
pp. 7438-7447 ◽  
Author(s):  
William C. Richardson ◽  
Turmandakh Badrakh ◽  
Bruce A. Roundy ◽  
Zackary T. Aanderud ◽  
Steven L. Petersen ◽  
...  

2020 ◽  
Vol 42 ◽  
Author(s):  
Alexandre Carneiro da Silva ◽  
Maiara Pilar Palmeira da Silva ◽  
Rayssa Zamith ◽  
Gustavo Galetti ◽  
Fatima Conceição Márquez Piña-Rodrigues

Abstract: Direct seeding is a technology that reduces the costs of forest restoration projects and favors species which are difficult to establish for seedlings. The seeds osmotic treatment to accelerate and standardize germination and induce tolerance to environmental stresses may favor seedling establishment in field through direct sowing and contribute to the greater efficiency of this technique. With the purpose of favor seed germination and seedling establishment under direct seeding conditions in the field, Tabebuia roseoalba osmoprimed seeds in polyethylene glycol (PEG) solution and unconditioned seeds were treated with isolated and/or combined solutions of plant growth regulators (PGR) and rooting (RTG). These seeds were submitted to germination test and evaluated for percentage germination rate, germination speed index and normal seedlings, and to seedling emergence test by direct field seeding. RTG had a toxic effect on T. roseoalba seeds. Osmoconditioning induced stress tolerance by RTG during germination and on seedling establishment. PGR treatment favors seedling emergence in field conditions and alleviates the toxicity effect caused by RTG. These treatments have great potential for use in direct sowing of T. roseoalba seeds.


2021 ◽  
Vol 22 (11) ◽  
Author(s):  
Edgardo P. Lillo ◽  
ARCHIEBALD B. MALAKI ◽  
STEVE MICHAEL T. ALCAZAR ◽  
RAAMAH ROSALES ◽  
BERNARDO R. REDOBLADO ◽  
...  

Abstract. Lillo EP, Malaki AB, Alcazar SMT, Rosales R, Redoblado BR, Diaz JLB, Pantinople EM, Buot Jr. IE. 2021. Inventory of native and mother trees in Key Biodiversity Areas of Cebu Island, Philippines for species selection in local reforestation programs. Biodiversitas 22: 4740-4749. Forest restoration is the counterforce of deforestation and forest degradation. Yet, despite promoting natural recovery after forest harvest, afforestation and reforestation efforts, tropical forest ecosystems still experience a poor ratio of forest loss to forest gain. The study assessed the native tree species and potential mother trees in different Cebu Island Key Biodiversity Areas (KBAs) as well as their distribution and habitat preferences which can be used in local reforestation programs. A vegetation survey was conducted in three KBAs in Cebu Island, namely Nug-as forest, Mount Lantoy and Mount Capayas to inventory all native species. Assessment based on the phenotypic characteristics of adult trees was also conducted for indicating mother trees. This study in Cebu Island KBAs recorded a total of 292 species, categorized into 125 families and 203 genera, which can be classified into native trees (210), vines and lianas (18), shrub (37), and herbs (27). Out of the 292 species, 214 were recorded in Nug-as forest, 172 in Mount Lantoy, and 145 in Mount Capayas. Of the 210 native tree species, Nug-as forest had 145 species, Mount Lantoy 131 species, and Mount Capayas 109 species. A total of 241 mother trees were identified in the three KBAs, corresponding to 77 species in which Nug-as forest had 143 trees correspond to 52 species, Mount Lantoy had 68 trees correspond to 29 species, and Mount Capayas had 31 trees correspond to 6 species. Such native tree species are recommended for reforestation programs as planting materials that could reduce the risks of failure due to its high adaptability to the environment.


2020 ◽  
Vol 12 (17) ◽  
pp. 7190
Author(s):  
Luca Giupponi ◽  
Valeria Leoni

Stabilization of slopes subject to landslide by measures with low impact, such as those of bioengineering, is a topic of interest. The use of scarcely studied alpine pioneer plants could contribute to innovation in soil bioengineering and restoration ecology but to use them, knowledge of the ex situ germinability of their seeds is fundamental. This research analysed the germinability of seeds of nine alpine pioneer species (Papaver aurantiacum, Rumex scutatus, Tofieldia calyculata, Pulsatilla alpina, Silene glareosa, Adenostyles alpina, Dryas octopetala, Laserpitium peucedanoides and Laserpitium krapfii) treated with water, gibberellic acid (GA3) and/or calcium carbonate at room temperature. The seeds had different responses to the treatments: Laserpitium peucedanoides, L. krapfii and Silene glareosa showed difficulty in germinating (germination < 2.5%), while Dryas octopetala had good germination (39–61%) regardless of treatment. GA3 significantly increased the seed germination rate of Papaver aurantiacum, Pulsatilla alpina, Rumex scutatus and Tofieldia calyculata, while the addition of calcium carbonate made the seeds of Rumex scutatus and Tofieldia calyculata germinate more quickly. Results are discussed focusing on the perspectives of using alpine pioneer species in future soil bioengineering work for slopes stabilization and restoration, and on the actions that stakeholders should take to make this happen.


2021 ◽  
Vol 14 (1) ◽  
pp. 101-114
Author(s):  
Ade Ayu Oksari ◽  
Irvan Fadli Wanda ◽  
Gladys Ayu Paramita Kusumah Wardhani

AbstrakDioscorea bulbifera L. (Dioscoreaceae) merupakan salah satu tanaman invasif yang menciptakan masalah lingkungan. D bulbifera mengandung alelopati yang memengaruhi proses fisiologis pada spesies lain. Penelitian ini bertujuan untuk mengetahui pengaruh alelopati berbagai konsentrasi ekstrak daun dan umbi D. bulbifera L. terhadap perkecambahan biji Shorea selanica (Lam.) Blume. Metode yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan sepuluh perlakuan dan tiga ulangan. Perlakuan yang diberikan adalah perbedaan konsentrasi ekstrak D. bulbifera 25, 50, 75, 100%, dan kontrol. Berdasarkan hasil uji skrining fitokimia, semua metabolit sekunder dalam ekstrak daun menunjukkan hasil yang positif. Senyawa golongan saponin, tanin, flavonoid, dan steroid/terpenoid terdeteksi dengan kuat sedangkan senyawa alkaloid kurang kuat. Senyawa fenol tersebut adalah fenol, 1,2-benzenediol (dalam ekstrak daun) dan fenol, 1,2-benzendiol, 1,4-benzendiol, dan 2-metoksifenol (dalam ekstrak umbi). Berdasarkan uji perkecambahan, ekstrak metanol umbi dan daun D. bulbifera berpengaruh nyata terhadap daya kecambah, koefisien kecepatan berkecambah, dan koefisien keserempakan berkecambah S. selanica. Konsentrasi yang menurunkan viabilitas biji terendah adalah pada konsentrasi 75% dan 100% dengan rata-rata daya kecambah 10,00 ± 6,32 % (pada ektrak umbi) dan 0,00 ± 6,32 % (pada ektrak daun). AbstractDioscorea bulbifera L. (Dioscoreaceae) is one of the most unutilized invasive plants. This plant contains allelopathy that affects the physiological process of native species. This study aimed to discover the type of allelochemical in D. bulbifera and its effect on seed germination of Shorea selanica (Lam.) Blume. The method used was a Completely Randomized Design with ten treatments and three replications. The treatment given was the different concentration of D. bulbifera extract of 25, 50, 75, 100%, and control. Based on phytochemical screening tests, saponin, tannin, flavonoid, and steroid/terpenoid compounds were detected in leaf and tuber extract. The total phenolic in leaf extract was more significant than that in the tuber extract of D. bulbifera but the type of phenolic compounds was lower. The phenolic compounds were phenol, 1,2-benzenediol (in leaf extracts) and phenol, 1,2-benzendiol, 1,4-benzendiol, and 2-methoxyphenol (in tuber extracts). Based on the germination test, it was found that the methanol extract from the tubers and leaf of D. bulbifera significantly affected the germination capacity, coefficient rate of germination, and simultaneity coefficient of germination of S. selanica. It was found that treatment of concentration of 75% and 100% resulted in the lowest seed viability reduction with an average germination rate of 10.00 ± 6.32% (in tuber extracts) and 0.00 ± 6.32% (in leaf extracts).


2020 ◽  
Vol 14 (2) ◽  
pp. 1-12
Author(s):  
Nurul Ihsan Fawzi

Deforestation in Kalimantan island made 17 million hectares of primary forest loss in the last 40 years. The forest restoration project needs native species seedlings from the previous tree on the damaged forest. The aim of this study to determine the germination and growth of the types of Shorea obtained from TNGP. This study used 38,728 seeds from four species of the Shorea genus: red meranti (Shorea leprosula), Tengkawang (Shorea macrophylla), white meranti (Shorea agami), and belabak (Shorea quadrinervis) obtained from forests near reforestation sites. The result show the average germination rate is 80%. The highest germination rate from the Shorea quadrinervis was 98.7%. We found that the growth of the Shorea genus from seeds was ready for planting in a period of 4 - 5 months.


Helia ◽  
2000 ◽  
Vol 23 (33) ◽  
pp. 97-104
Author(s):  
F.M. Khalifa ◽  
A.A. Schneiter ◽  
E.I. El Tayeb

SUMMARY Seed germination of six sunflower (Helianthus annuus L.) hybrids was investigated across a range of eleven constant temperatures between 5°C and 45°C. Large temperature differences in germination rate 1/t (d-1), cardinal temperature (°C) and thermal time θ (°cd) were observed among hybrids. Base temperatures (Tb) varied between 3.3°C and 6.7°C whereas maximum germination temperatures (Tm) varied between 41.7°C and 48.9°C. Final germination fraction was attained at 15°C - 25°C whereas the maximum rate of germination was attained at 30.4°C - 35.6°C. The maximum germination rate of hybrid USDA 894, the cultivar with the slowest germination rate, was only 50% of that of hybrid EX 47. The low Tb and high Tm of sunflower appear to be one of the factors which explain the successful adaptation of sunflower to a wide range of temperature. These findings are discussed in relation to the origin of the crop and its wide adaptations in diverse habitats and climatic zones.


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