The aims of the study were to analyze (1) the effects of Prosopis juliflora (Prosopis) on the spatial distribution and soil seed banks (SSB) diversity and density, (2) the effects of environmental factors on SSB diversity and density (number of seeds in the soil per unit area), and (3) the effects of animal fecal droppings on SSB diversity, density, and dispersal. Aboveground vegetation data were collected from different Prosopis-infested habitats from quadrats (20 × 20 m) in Prosopis thickets, Prosopis + native species stand, non-invaded woodlands, and open grazing lands. In each Prosopis-infested habitats, soil samples were collected from the litter layer and three successive soil layer, i.e., 0–3 cm, 3–6 cm, and 6–9 cm. Seeds from soil samples and animal fecal matter were separated in the green house using the seedling emergence technique. Invasion of Prosopis had significant effects on the soil seed bank diversity. Results revealed that the mean value of the Shannon diversity of non-invaded woodlands was being higher by 19.2%, 18.5%, and 11.0% than Prosopis thickets; Prosopis + native species stand and open grazing lands, respectively. The seed diversity and richness, recovered from 6–9-cm-deep layer were the highest. On the other hand, the density of Prosopis seeds was the highest in the litter layer. About 156 of seeds/kg (92.9%) of seeds were germinated from cattle fecal matter. However, in a small proportion of seedlings, 12 of seeds/kg (7.1%) were germinated from shot fecal matter. Thus, as the seeds in the soil were low in the study areas, in situ and ex situ conservation of original plants and reseeding of persistent grass species such as Cynodon dactylon, Cenchrus ciliaris, Chrysopogon plumulosus, and Brachiaria ramosa are recommended.
Tag: groundwater flow
The Effect of Fire and Rewetting on the Groundwater Level in Tropical Peatlands
Hydrological system strongly influences the sustainability of peatlands. The drainage system in peatlands that is not designed appropriately will result in the drop of groundwater level (GWL), and thus, peat will be dried and become susceptible to fire. Efforts to restore peatlands have been carried out, one of which is peat rewetting through canal blocking. This study assessed the non-burnt and burnt peatland areas as well as an area with canal blocking to determine the effect of fire and canal blocking on the GWL for the foregoing variables. In each area, dipwells were established at a distance of 1 m (representing the canal water level), 10, 50, 100, 250, and 350 m from the canal. The study clearly showed a significant correlation between the average GWL and fire, and canal blocking as well as the distance from the canal. Fire resulted to an increase of the average GWL, from 61 cm to 50 cm below the ground. There were significant impacts on land use relevant to the average GWL. Canal blocking demonstrated its role in increasing GWL on drained peat areas by mimicking the average GWL on the reference site. This study concluded that constructing more canal blockings and planting more fire-resistant plants are critical to reduce the fire risks.