Natural seedling recruitment and regeneration in deforested and sand‐filled Mangrove forest at Eagle Island, Niger Delta, Nigeria

Abstract

Seed recruitment is a major driver of mangrove restoration globally. It is hypothesized that soil condition and channel hydrology can accelerate seedling recruitment and regeneration after a major disturbance. Species abundance, diversity indices, microbial and chemical concentrations in sand‐filled mangrove forest was studied. Eight plots measuring 487.77 m2 each were established with ten transects in each plot in a random block design to investigate the effect of soil conditions on seedling growth. A total of 1,886 seedlings were counted. Seedling abundance was significantly different between red (Rizophora racemosa), white (Laguncularia racemosa), and black (Avicennia germinans) mangroves, and nypa palm (nypa fruticans). The most dominant species was black mangrove, and the least dominant species was nypa palm. Muddy soils had the most abundant species (n = 994) followed by sandy (n = 457) and semi‐muddy (435) soils. Furthermore, sandy soils had the highest species diversity (H = 0.896) followed by semi‐muddy (H = 0.876) and muddy (H = 0.583) soils. The soil metal concentration has no correlation with seed abundance and occur in the order Iron > Nitrate > Copper > Cadmium. Soil with high species diversity had high soil microbial population; however, seedling abundance was correlated with soil nutrients and not heavy metals. Small seeds are easily recruited while good soil condition plus existing hydrological connection facilitated natural seedling regeneration in the disturbed mangrove forest.

Environmental Impact of Bush Burning on the Physico-Chemistry of Mangrove Soil at Eagle Island, Niger Delta, Nigeria

“…Nitrates have the least concentration and are the primary source of nitrogen used for plant growth. Previous study had also reported low nitrate concentration in the same site [24].…”

“…Thus, the degradation of soil chemical composition through the application of fire can impact revealed that the concentration of iron was the highest because of the sedimentary makeup of the base rock of the coastal environment as shown by previous studies in that location [3] [23]. Iron exudes from the base soil to the topsoil after every ebb tide, which mostly occur because of an earlier sand filling activity that brought sandy soil from sea bottom onto the land surface in the study area [24]. Magnesium too was the next dominant metal in the study sites and had originated from silicates in the base rock.…”

Impact of Polluted Soil on Herbivory of Leaves and Pneumatophore Growth of Black Mangroves (Laguncularia racemosa) at Eagle Island, River State, Nigeria

“…"Pneumatophores dominate this study area because of the large population of black mangroves" [16]. "They grow in large or small populations underneath the black mangrove trees.…”

Regenerasi Alami Semaian Mangrove Di Kawasan Teluk Benoa, Bali

“…Keberadaan semai mangrove yang lebih tinggi dibandingkan dengan tegakan pancang dan pohon, dapat menggambarkan bahwa regenerasi dari suatu hutan berjalan dengan baik (Shankar, 2001;Abrar et al, 2018;Rahmania et al, 2019). Regenerasi hutan dapat berjalan dengan baik apabila didukung oleh lingkungannya seperti kesehatan mangrove, cahaya yang optimal, kondisi perairan serta substrat yang sesuai (Nurdiansah & Dharmawan, 2018;Numbere, 2021).…”