Indonesian agroforestry has been developed along the history, since been reported that home garden was practiced from 3,000 BC in Java Island. However, agroforestry practices were recognized to have less contribution to people welfare and environmental sustainability. Bibliometric and literature studies extracting baseline information from thousands of publications were done to analyse history and future projection of Indonesian agroforestry. Research and publication on Indonesian agroforestry is steadily increasing in number and quality. Topics related with traditional land use system and ecosystem services were frequently found, and therefore classified as motor themes. There were 16 most attractive commodities stated in the publications, including palm oil and rubber. Rubber agroforest was the only system that pay interest in several decades. There were many researches on indigenous agroforestry practices in the islands, but mostly (77%) concentrated in Java Island, especially studying private forest and home garden. The research on the issues of population pressure on forestland and efficient use of resources are the most popular topic in the decades. In the recent decade, broader theme of research was found including climate change and long-term livelihood. Based on the study, indigenous agroforestry is still important subject to study, but future roadmap of agroforestry must be developed by integrating forestry and agriculture approaches.
Abstract. Marpaung BA, Budiadi, Pertiwiningrum A, Lestari LD, Nurjanto HH, Widiyatno. 2022. Interspecific associations of mangrove species and their preferences for edaphic factors and water quality. Biodiversitas 23: 4626-4635. Scientists from different regions have reported failures of mangrove restorations that were predicted due to the unsuitability of the species for the habitats. Habitat preferences should become an important consideration for mangrove restoration and management. This study aimed to find interspecific associations between species and examine the edaphic factors and water quality suitable for mangroves. Eight research stations (and 24 sample plots) were established purposively based on the vegetation structure and salinity levels in successful mangrove restorations in East Lampung in 2020. In each plot, vegetal data and sediment and water samples were taken. The species domination was analyzed using the important value index (IVI), and interspecific associations were determined using a 2x2 contingency table. The edaphic factors and water quality were analyzed using principal component analysis (PCA) to find factors that had significant correlations among others. The effects of the edaphic factors and water quality on species regeneration were analyzed using multiple linear regression by backward elimination to develop a model of habitat preferences for mangroves. Based on the results, Avicennia marina and Rhizophora sp. were the dominant species in all the zones. Still, the lack of interspecific association ( ) showed that both species had different preferences for the habitat. We found four principal components (PCs) of edaphic factors—i.e., the environmental (soil and surface) temperature, dusty clay and Ca, inorganic nitrogen (NH4-N and NO3-N), and Mg—and two PCs of water quality, i.e., nontoxic pollutants (total suspended solids and turbidity) and anthropogenic factors (NO2-N and PO4-P), as predictors for multiple linear regression. The seedlings of A. marina had no specific preferences for edaphic factors but significantly preferred nontoxic pollutants (R2 = 0.619), while the seedlings of Rhizophora spp. significantly preferred a specific environmental temperature, dusty clay and Ca, and inorganic nitrogen (R2 = 0.768), and nontoxic pollutants (R2 = 0.755). Combining A. marina and Rhizophora spp. in mangrove restorations should be avoided. Therefore, spatial planting patterns or sequential planting based on the succession stages of the habitat could be established.
A new massive dieback case of Avicennia marina was observed in the area of the Sunda Strait, which started in 2020, and the cause is still unknown. This research was conducted to report the rate of mangrove degradation, measure biomass loss, and predict the causes of the dieback. A sequential imagery analysis (2019–2022) was conducted to interpret the area changes using a research area of 200 ha from the total 528.69-ha mangrove, using the plant senescence reflectance index (PSRI) and normalized difference vegetation index (NDVI). Field data were collected before and during the dieback event (2020 and 2021) at seven research stations including, live mangroves, partial dieback, and full dieback sites. Biomass loss was measured as standing stock volume (SSV) and total biomass carbon (TBC). A literature study was conducted to predict the cause of the dieback. Based on the results, the mangrove dieback caused a rapid and significant loss of healthy stands (results of the PSRI) and very-high-density stands (results of the NDVI). The rate of healthy stand loss was 13.43 ha month−1 (during July–October 2020) and that of very-high-density stand loss was 14.99 ha month−1 (October 2020–April 2021), which affected 126.62 ha or 24% of the total area (last measurement in January 2022). The SSV before dieback was 118.70 (±46.1) m3 ha−1, but within 14 months, it decreased to 20.8 (±6.0), 79.80 (±52.3), and only 1.0 (±1.0) m3 ha−1 for live, partial dieback, and full dieback stands, respectively. The TBC of live mangroves (before dieback) was 51.6 (±24.4) Mg C ha−1, but within the same period, it changed to 30.70 (±3.80), 69.50 (±14.6), and 51.60 (±9.4) Mg C ha−1 for live, partial dieback, and full dieback stands, respectively. Based on the literature study and field observation, the dieback was probably related to less flushing and long-term inundation by the decrease in rainfall intensity, in addition to nitrogen (NO3−N and NO2−N) enrichment, an over-supply of N from fishpond wastes. Sustainable silvofishery may be introduced to ameliorate water and soil quality.
Penelitian ini bertujuan untuk menjelaskan pengaruh diskon dan kemudahan bertransaksi terhadap keputusan pembelian di e-commerce shopee terkhusus pada mahasiswa Fakultas Ekonomi dan Bisnis, Universitas Negeri Surabaya. Jenis penelitian yang digunakan dalam penelitian yaitu menggunakan penelitian kuantitatif deskriptif, populasi dalam penelitian ini yaitu pengguna aplikasi e-commerce shopee. Penelitian ini menggunakan populasi sebanyak 2.950 mahasiswa dengan sampel berdasarkan rumus Slovin berjumlah sebanyak 97 mahasiswa pada penelitian ini pengambilan sampel dilakukan dengan cara purposive sampling, sampel sebanyak 97 mahasiswa digunakan untuk pengambilan data dengan cara menyebar kuesioner. Sedangkan teknik analisis data yang digunakan adalah teknik analisis regeresi linier berganda. Hasil penelitian menunjukan bahwa nilai signifikasi hasil dari analisis variabel diskon (X1) terhadap variabel keputusan pembelian (Y) pada e-commerce shopee bepengaruh positif, dan nilai signifikasi hasil dari variabel kemudahan bertransaksi (X2) juga memberikan pengaruh positif terhadap variabel keputusan pembelian (Y) pada e-commerce shopee. Hasil penelitian menunjukan bahwa diskon dan kemudahan bertransaksi berpengaruh secara simultan terhadap kepuusan pembelian sebesar 53,7% dan 46,3% dipengaruhi oleh variabel independen lainnya. Kata Kunci: kemudahan bertransaksi; e-commerce; keputusan pembelian
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