The potential of Nephrolepis biserrata fern as ground cover vegetation in oil palm plantation

Satriawan H, Fuady Z, Ernawita. 2021. The potential of Nephrolepis biserrata fern as ground cover vegetation in oil palm plantation. Biodiversitas 22: 4808-4817. Nuisance plants or weeds are commonly found in agricultural landscapes including in oil palm plantations. Despite being considered as weeds, several of them have the potential to be used as ground cover vegetation including Nephrolepis biserrata (Sw). Schott. This fern species exhibits beneficial characteristic as ground cover plant especially in terms of the contribution of organic matter and soil moisture through the prevention of evapotranspiration. The objective of this research is to explore the potential of N.biserrata as ground cover vegetation in oil palm plantations based on the assessment of its ecological characteristics regarding the growth and decomposition rate, tolerance to shade, organic contents and carbon accumulation. The split plot experimental design was used with the age of oil palm plants was used as main plot while in the sub-plots the spacing of N. biserrata was used at three varying distances 10x10cm, 20x20 cm, and 30x30 cm, each treatment had three replicates. Nine parameters observed were the percentage of growth, the percentage of ground cover, plant height, fronds number per plant, leaves number per plant, Leaf Area Index, dry weight (g), nutrient content in plant tissue, and potential carbon stock. Results showed that N. biserrata showed rapid growth in covering the ground surface (8-12 weeks after planting), had rapid decomposition rate (30-60 days), tolerant to shading which was characterized by the highest percentage of growth up to 81.16% and covering area up to 95.9%, accumulated organic contents of N (1.23-1.53%), P (0.18-0.22%), and K (1.4-1.67%), respectively. In addition, total dry weight biomass obtained was 27.1 ton/ha, accumulated carbon in plant of 0.9 tons C/ha/year, and amount of soil carbon stock 76.4-97.4 tonnes/ha/year. The results of this study suggest that Nephrolepis biserrata is a potential plant to be utilized as a ground cover plant in oil palm plantations.

The Diversity of Ferns (Pteridophyta) in North Sumatera (Case Study: Batang Gadis National Park Resort 7 Sopotinjak)

Introduction: Ferns (Pteridophyta) are plant communities that have an ecological function as ground cover vegetation. The purpose of this research types of ferns (Pteridophyta) and the diversity index of ferns found in the Batang Gadis National Park Resort 7 Sopotinjak, Batang Natal Sub-district, Mandailing Natal District, North Sumatra Province. Materials and Methods: Descriptive survey method using quadratic plot of 24 plots in three transects. Results: It was found that five from 28 species of dominant fern were: Asplenium nidus, Asplenium normale, Shaeropteris glauca, Oleandra undulate, and Asplenium lobulatum. The diversity index of ferns (Pteridophyta) of 2.494 and was categorized as moderate, which means that the ferns (Pteridophyta) are stable, this indicates that the ecosystem is in a fairly balanced state.

Impact of ground cover vegetation types on the diversity and similarity of spider assemblage at two adjacent sites

Spider (Arachnida) is one of the classes of arthropods known to give strong responses to differences in land cover vegetation. This study intended to investigate whether the difference of vegetation types that are located adjacently occupied by the same genera of spiders. Two adjacent areas in Liwa Botanical Garden that covered by two different types vegetation were assigned as the sampling sites. The spiders sampling was carried out over a 100 meter long transect line (5 lines each) by applying active searching and pitfall trapping techniques. There were 21 genera from 9 spider families that were collected from two sampling sites. In the land vegetated with wood, there were 12 genera with 129 specimens. In the herbaceous land, there were 13 spider genera with 120 specimens. The Simpson's index of diversity were 0.7739 and 0.8868, meanwhile the Shannon's index were 1.8575and 2.2831, respectively obtained at herbaceous and woody land. The difference of diversity between two compared sites by Hutcheson t-test was highly significant (α < 0.01). This presumption is also supported by the coefficient of dissimilarity calculated using Sorensen’s index formula (Ss = 75.7575). Thus it can be concluded that the different types of land cover vegetation have a significant impact on the diversity of the dwelling spiders even though the two fields are located adjacent to each other.

Ground Cover Vegetation Promotes Ecological Intensification of Pear Production

The use of ground cover vegetation is becoming a prominent intervention for promoting biodiversity and associated ecosystem services in Chinese orchards. Despite the large number of studies that have examined the effects of ground cover vegetation on promoting natural enemy populations and related natural pest control, it is less understood whether enhanced natural pest control translates to increase yield and reduced pesticide use. We conducted a 2-year experiment comparing three cover vegetation (ryegrass, clover, and hairy vetch) practices versus a bare ground control in commercial pear orchards in the Yangtze River Delta of East China (YRDEC), China. Natural enemy density (predator and parasitoid abundance), invertebrate herbivore performance (piercing-sucking herbivore abundance and branch-boring and fruit-boring percentage), pesticide input and pear fruit yield were recorded. The results indicated that cover vegetation decreased herbivore abundance and boring percentage by 49.95 and 63.6% respectively, and thus decreased pesticide use by 26.10%. Meanwhile, we found that cover vegetation increased the abundance of natural enemies by 620.75%, and increased pear fruit yield by 6.82%. Piecewise structural equation modelling indicated that increased natural enemy densities, decreased herbivore performance and pesticide use, while increasing fruit yield. Our results confirm that the use of ground cover vegetations (especially with clover and hairy vetch) can promote ecological intensification and biological pest control in pear orchards.

Populations and Host/Non-Host Plants of Spittlebugs Nymphs in Olive Orchards from Northeastern Portugal

The Aphrophoridae family contains important vectors of Xylella fastidiosa, a serious bacterial plant disease. In olive orchards, nymphs usually feed on the ground-cover vegetation. However, detailed information about their populations and host/non-host plants in some regions threatened by Xylella, such as the northeast of Portugal, is very limited. The goal of our work was to identify the vector species, nymphal development period, and their host and non-host herbaceous plants in olive orchards from northeastern Portugal. Ground-cover plant species hosting or not hosting nymphs were identified during the spring of 2017 to 2019 in olive orchards. Nymphal development period, nymph aggregation, and nymph’s preferred feeding height of the ground-cover plants were recorded. The most abundant Aphrophoridae species was Philaenus spumarius followed by Neophilaenus sp. Nymphs developed from April to early May and showed a low number of individuals per foam (generally between one and three). They preferred the middle part of the plants. Philaenus spumarius feeds preferentially on Asteraceae and Fabaceae, and Neophilaenus sp. on Poaceae. Some abundant plants, such as Bromus diandrus, Astragalus pelecinus, Chrysanthemum segetum, Trifolium spp., Caryophyllaceae, and Brassicaceae, were barely colonized by Aphrophoridae nymphs. This knowledge is essential for the selection of the species composition of ground-cover vegetation to minimize the presence of vectors of X. fastidiosa in olive groves.

Effect of salvage-logging on post-fire tree establishment and ground cover vegetation in semi-natural hemiboreal forests

Fire is a common disturbance in boreal forests causing changes in biological diversity at various spatial scales. In the past 100 years, forest management has limited fire outbreaks, but in the future, the fire-affected forest area is expected to increase in many regions due to climate change. Burned forests are typically salvage-logged, but the effect of this type of management versus natural regeneration on biological diversity is not well understood, particularly the mid-term effect to tree establishment and understory vegetation composition and diversity. Various management methods were used after a large fire in 1992 in a peatland-forest complex and neighbouring managed forests, which created an experimental setup for study of the effect of management after fire in the Sliteres National park, northwestern Latvia. Understory vegetation was described in plots using a design of four forest and three management types: natural regeneration (unmanaged) and managed sites with salvage logging followed by no further human intervention and salvage logging with planting. Post-fire management had different effect in each forest type. Species richness was higher in forest types with salvage logging than in natural regenerated sites on rich wet and rich dry forest types, but not for the poor forest types. Tree regeneration was generally greater in salvage-logged stands, but differed between forest types. Species composition was related to tree regeneration and canopy openness. In contrast to other studies, salvage logging had a positive mid-term effect to ground vegetation diversity and tree establishment in the studied stands, implying potential for concomitant management and conservation of ground cover vegetation in semi-natural stands.

Land use conversion from peat swamp forest to oil palm agriculture greatly modifies microclimate and soil conditions

Oil palm (Elaeis guineensis) agriculture is rapidly expanding and requires large areas of land in the tropics to meet the global demand for palm oil products. Land cover conversion of peat swamp forest to oil palm (large- and small-scale oil palm production) is likely to have negative impacts on microhabitat conditions. This study assessed the impact of peat swamp forest conversion to oil palm plantation on microclimate conditions and soil characteristics. The measurement of microclimate (air temperature, wind speed, light intensity and relative humidity) and soil characteristics (soil surface temperature, soil pH, soil moisture, and ground cover vegetation temperature) were compared at a peat swamp forest, smallholdings and a large-scale plantation. Results showed that the peat swamp forest was 1.5–2.3 °C cooler with significantly greater relative humidity, lower light intensities and wind speed compared to the smallholdings and large-scale plantations. Soil characteristics were also significantly different between the peat swamp forest and both types of oil palm plantations with lower soil pH, soil and ground cover vegetation surface temperatures and greater soil moisture in the peat swamp forest. These results suggest that peat swamp forests have greater ecosystem benefits compared to oil palm plantations with smallholdings agricultural approach as a promising management practice to improve microhabitat conditions. Our findings also justify the conservation of remaining peat swamp forest as it provides a refuge from harsh microclimatic conditions that characterize large plantations and smallholdings.