Estimating Rates of Nutrient Recovery Following Timber Harvesting in a Second Growth Forest of Peninsular Malaysia

Author(s):  
Yusop Zulkifli ◽  
Kasran Baharuddin ◽  
Nik Abdul Rahim
2021 ◽  
Vol 499 ◽  
pp. 119604
Author(s):  
Romy Carpenter ◽  
Elisabeth B. Ward ◽  
Jessica Wikle ◽  
Marlyse C. Duguid ◽  
Mark A. Bradford ◽  
...  

2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity


2020 ◽  
Vol 5 (1) ◽  
pp. 374
Author(s):  
Pauline Jin Wee Mah ◽  
Nur Nadhirah Nanyan

The main purpose of this study is to compare the performances of univariate and bivariate models on four time series variables of the crude palm oil industry in Peninsular Malaysia. The monthly data for the four variables, which are the crude palm oil production, price, import and export, were obtained from Malaysian Palm Oil Board (MPOB) and Malaysian Palm Oil Council (MPOC). In the first part of this study, univariate time series models, namely, the autoregressive integrated moving average (ARIMA), fractionally integrated autoregressive moving average (ARFIMA) and autoregressive autoregressive (ARAR) algorithm were used for modelling and forecasting purposes. Subsequently, the dependence between any two of the four variables were checked using the residuals’ sample cross correlation functions before modelling the bivariate time series. In order to model the bivariate time series and make prediction, the transfer function models were used. The forecast accuracy criteria used to evaluate the performances of the models were the mean absolute error (MAE), root mean square error (RMSE) and mean absolute percentage error (MAPE). The results of the univariate time series showed that the best model for predicting the production was ARIMA  while the ARAR algorithm were the best forecast models for predicting both the import and export of crude palm oil. However, ARIMA  appeared to be the best forecast model for price based on the MAE and MAPE values while ARFIMA  emerged the best model based on the RMSE value.  When considering bivariate time series models, the production was dependent on import while the export was dependent on either price or import. The results showed that the bivariate models had better performance compared to the univariate models for production and export of crude palm oil based on the forecast accuracy criteria used.


2018 ◽  
Vol 70 (1) ◽  
pp. 103-108
Author(s):  
A.R. Rafidah ◽  
◽  
A.R. Ummul-Nazrah ◽  
M.A. Mohd Hairul ◽  
◽  
...  

1985 ◽  
Author(s):  
Robert S. Seymour ◽  
Gordon D. Mott ◽  
Steven M. Kleinschmidt ◽  
Peter Triandafillou ◽  
Robert Keane

2019 ◽  
Author(s):  
João Macedo Moreira ◽  
Aldrin Martin Pérez-Marin ◽  
Jucilene Silva Araújo ◽  
George Rodrigues Lambais ◽  
Aldo Sales

The study aimed to evaluate the efficiency of nutrient use in three cactus forage (CF) cultivars (Opuntia stricta and Nopalea cochenillifera), 365 days after planting under different types of fertilizer in two research sites (Condado and Riachão) of the semi-arid region of Paraiba state, Brazil. The experimental design was a randomized block design with treatments in a factorial scheme (3×4), three cultivars of CF (Orelha de elefante Mexicana; Miúda; Bahiana), and four fertilizer treatment (Control; Manure; Manure with Nitrogen; Mineral fertilization) with four replications. The CF cultivars did not differ significantly in nutrient use. That means of physiological efficiency by CF cultivars were 1.62, and 2.36 kg of biomass per kg of nutrient applied in Condado and Riachão, respectively. The efficiency of nutrient recovery was 16% for the Condado, according the following order: K> P> Ca> N> C = Mg and 12% for Riachão: K> P> N> C = Ca = Mg. In the two research sites, the treatment with mineral fertilization significantly increased the efficiency use of N, P and K in comparison to the other treatments. The average for efficiency of nutrient utilization was 25% and 19% for Condado and Riachão, respectively, in the following order for Condado: K> P> N> Ca = Mg> C, and Riachão: K> P> N> C> Mg = Ca. In a CF production system aiming to obtain a yearly harvest cycle, it is necessary to replenish of K and P to maintain the nutritional balance between the soil and CF plant.


2019 ◽  
Vol 28 (2) ◽  
pp. 356-359
Author(s):  
E.P. Nartshuk ◽  
A.V. Matyukhin ◽  
A.P. Shapoval

The parasitic louse fly Ornithomya comosa (Austen, 1930) (Diptera, Hippoboscidae), known from the Oriental Region (India, Thailand, Nepal and Peninsular Malaysia) and Asian part of the Palaearctic Region (Kazakhstan, Kyrgyzstan, West Siberia of Russia and Japan), is found for the first time in Europe and in the western part of Russia (Curonian Spit). Flies were collected from the swallow species Hirundo rustica (Linnaeus, 1758) and Delichon urbica (Linnaeus, 1758) (Hirundinidae). Two possible narratives for the occurrence of this fly in Europe are discussed.


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