Growth Performance of Hill Dipterocarp Forests Five Years after Harvesting at the Angsi Forest Reserve, Negeri Sembilan, Malaysia, 2007

The future long-term timber supply from sustainably managed forest in Peninsular Malaysia is largely dependent on the availability of timber from the productive Permanent Forest Estate (PFE) especially from the Hill Dipterocarp Forests. Future log supply also will come from the second and successive harvest in logged-over forest. Specific information on behaviours of particular forest stand pertaining to growth performance, mortality, density, structure and species composition is required to evaluate the management systems and its suitability under different forests types. The study was conducted in a logged over Hill Dipterocarps Forest in Angsi Forest Reserve, Negeri Sembilan with the objective to evaluate the growth response five years after harvesting. The data consist of five annual measurements (2000-05) collected from four I-ha permanent sample plots. The data were analysed in terms of diameter increments, basal areas, tree volumes and also growth projection using existing growth and yield model. The results show pattern and trend of tree growth five years after logging. The stocking of trees, basal area and volume for both trees over 5 and 30 cm dbh were significantly -different ( ~ ~ 0 . 0 5a)m ong plots, species groups and measurement years. The ANOVA also showed that the interaction between species groups, study plots and measurement years were also significant (~~0.05). Stocking of trees for both over 5 and 30 cm dbh showed an increment over the measurement period. However, the overall increment rates of all trees over 30 cm dbh were relatively low, when compared to the rates assumed under the Selective Management System (SMS). The overall diameter periodic annual increment (DPAI) of 0.65 cm tree-' yr-' for all trees over 30 cm dbh is considerably lower than the rate of 0.8 to 1.0 cm tree-' yr-' assumed under the SMS. Although the DPAI of the dipterocarps was higher than the non-dipterocarps, their overall contributions to forest growth was small due to their lower stocking in the residual stand. The overall mean annual mortality (3.51%) of all trees over 30 cm dbh for 5-year period was higher than that assumed under the SMS (0.9%). Based on these growth rates, anticipating a second cut in 25 to 30 years as stipulated under SMS, would not be applicable for this area. Therefore, future research on behaviour of the forest should be conducted. Based on projection of growth and yield model until year 60 indicates that growth in timber, basal area and the number of stems per hectare is increasing each period until end of the projection period (year 60) at slower state. This shows that the study areas will experience long growth period due to high density of trees in lower diameter class

Cattle-grazing in oil palm plantations sustainably controls understory vegetation

Oil palm agricultural practices need to be substantially changed in order to meet the global demand for more ethical and sustainable farming. Livestock integration is an innovative method to control understory vegetation in oil palm plantations, while reducing the need for chemical herbicides, as well as providing additional food security, ecosystem services, and habitat heterogeneity. Understory vegetation is important for faunal biodiversity in oil palm plantations, however it is often decimated by the over usage of herbicides. To determine how cattle-grazing affected the growth of understory vegetation, we collected data from 45 plantations, in Peninsular Malaysia, including those integrated with cattle and without them. Our results revealed that the plantations integrated with cattle had on average 20% more undergrowth coverage, but no difference in undergrowth height, therefore, maintaining undergrowth at an acceptable height for harvesters to access oil palms. We recommend cattle-grazing as a method for oil palm stakeholders to maintain manageable undergrowth and align with sustainable palm oil certification policy by reducing their use of chemical herbicides. To promote cattle-oil palm integration, specific policies are needed to strengthen financial and technical support

Logged peat swamp forest supports greater macrofungal biodiversity than large-scale oil palm plantations and smallholdings

Intensive land expansion of commercial oil palm agricultural lands results in reducing the size of peat swamp forests, particularly in Southeast Asia. The effect of this land conversion on macrofungal biodiversity is, however, understudied. We quantified macrofungal biodiversity by identifying mushroom sporocarps throughout four different habitats; logged peat swamp forest, large-scale oil palm plantation, monoculture, and polyculture smallholdings. We recorded a total of 757 clusters of macrofungi belonging to 127 morphospecies and found that substrates for growing macrofungi were abundant in peat swamp forest; hence, morphospecies richness and macrofungal clusters were significantly greater in logged peat swamp forest than converted oil palm agriculture lands. Environmental factors that influence macrofungi in logged peat swamp forests such as air temperature, humidity, wind speed, soil pH, and soil moisture were different from those in oil palm plantations and smallholdings. We conclude that peat swamp forests are irreplaceable with respect to macrofungal biodiversity. They host much greater macrofungal biodiversity than any of the oil palm agricultural lands. It is imperative that further expansion of oil palm plantation into remaining peat swamp forests should be prohibited in palm oil producing countries. These results imply that macrofungal distribution reflects changes in microclimate between habitats and reduced macrofungal biodiversity may adversely affect decomposition in human-modified landscapes

Targeted cattle grazing as an alternative to herbicides for controlling weeds in bird-friendly oil palm plantations

The use of agrochemicals is expected to increase with the global expansion of oil palm plantations. In line with environmentally sustainable palm oil certification, targeted grazing can minimize the dependency on herbicides for controlling weeds in plantations. Here, we show for the first time that targeted grazing would control weeds and improve biodiversity of desired animal species. We sampled birds at 45 oil palm plantations in Peninsular Malaysia that were systematically grazed, non-systematically grazed, or herbicide-controlled plantations without cattle grazing. We found that bird species richness increased with size of grazing area, but decreased with number of cattle. Bird abundance was higher in the systematic grazing system, but negatively related to number of cattle. These factors explained 18.41 and 25.34% of the observed variations in bird species richness and abundance, respectively. Our findings suggest that targeted cattle grazing can be instrumental for transforming conventional oil palm agriculture into more biodiversity-friendly agroecosystems. Targeted grazing is likely to be practical under field conditions in major palm oil producing countries. In addition, the use of targeted grazing as a biological control method for weeds would be welcomed by palm oil consumers and encouraged by sustainable palm oil certification bodies such as the Roundtable on Sustainable Palm Oil (RSPO)

Predation of potential insect pests in oil palm plantations, rubber tree plantations, and fruit orchards

In human‐modified landscapes, important ecological functions such as predation are negatively affected by anthropogenic activities, including the use of pesticides and habitat degradation. Predation of insect pests is an indicator of healthy ecosystem functioning, which provides important ecosystem services, especially for agricultural systems. In this study, we compare predation attempts from arthropods, mammals, and birds on artificial caterpillars in the understory, between three tropical agricultural land‐use types: oil palm plantations, rubber tree plantations, and fruit orchards. We collected a range of local and landscape‐scale data including undergrowth vegetation structure; elevation; proximity to forest; and canopy cover in order to understand how environmental variables can affect predation. In all three land‐use types, our results showed that arthropods and mammals were important predators of artificial caterpillars and there was little predation by birds. We did not find any effect of the environmental variables on predation. There was an interactive effect between land‐use type and predator type. Predation by mammals was considerably higher in fruit orchards and rubber tree than in oil palm plantations, likely due to their ability to support higher abundances of insectivorous mammals. In order to maintain or enhance natural pest control in these common tropical agricultural land‐use types, management practices that benefit insectivorous animals should be introduced, such as the reduction of pesticides, improvement of understory vegetation, and local and landscape heterogeneity

Cattle grazing benefits farmland bird community composition in oil palm plantations

Oil palm expansion has caused considerable biodiversity loss as rainforest has been converted to plantation. However, it is still possible to mitigate such biodiversity losses and increase agricultural sustainability by introducing sustainable oil palm farming practices. One such method is the use of biological control agents for understory weed management in place of herbicides. Integrating cattle into oil palm plantation management to control undergrowth is expected to improve biodiversity (including avian diversity) in oil palm plantations. This study investigated the association between cattle grazing and farmland bird species composition in oil palm plantations. We used point transect sampling to survey farmland birds in 45 oil palm plantations which were divided into systematically and non-systematically cattle grazed plantations and control plantations (without cattle grazing). We found that both oil palm plantations with systematic (P=0.001) and non-systematic (P=0.005) cattle grazing had greater avian diversity than plantations without cattle grazing. Based on feeding guild, avian insectivores made up the majority of farmland birds observed. Bird species composition was determined by four attributes in our model: number of cattle, selective weeding frequency, age of oil palm stand, and palm height. We conclude that systematic grazing can improve avian diversity in oil palm plantations. We stress, that cattle integration into oil palm agriculture can provide an excellent means of maximising agricultural land use efficiency as well as increasing biodiversity in agricultural landscapes by increasing habitat complexity

Time to revisit oil palm-livestock integration in the wake of United Nations Sustainable Development Goals (SDGs)

To date, the idea of using livestock animals as biological tools to manage weeds, sequester carbon, and boost food security in oil palm plantations has not been seriously considered by industry stakeholders of major producing countries (e.g., Indonesia, Malaysia, Thailand, Colombia, and Nigeria). We revisit the integration of oil palm cultivation with livestock farming as a silvopastoral agroforestry practice in the wake of Sustainable Development Goals (SDGs). Oil palm-livestock integration has the potential to promote sustainable palm oil production because it can provide multiple environmental and socio-economic benefits, including carbon sequestration, restoring top soil, improving ecosystem biodiversity, reducing pesticide and fertilizer inputs, and boosting national food security. In contrast to monocultural outputs of most conventional plantations, an oil palm silvopastoral system is an ideal way to address the global food insecurity challenge as it produces bioenergy, vegetable oil/fat and animal-based protein sources (e.g., red meat). In addition, the potential of contract targeted grazing could be considered as a new type of business and income diversification for rural people. Oil palm-livestock integration is a strategy by the palm oil industry to achieve multiple SDGs. Out of the 17 SDGs, oil palm-livestock integration is likely to deliver nine SDGs. Palm oil certification bodies should recognize oil palm-livestock integration as a biological control method in weed management practices. We recommend that oil palm-livestock integration should be promoted to revitalize sustainable palm oil production and strategic biodiversity conservation policy. Policy makers should encourage major players in the palm oil industry to practice oil palm-livestock integration

Pasture production, nutritive value and water use efficiency of irrigated dairy pasture mixtures grazed by dairy cows

The objective of this thesis was to compare herbage dry matter (DM) production, nutritive value and water use efficiency of simple perennial ryegrass/white clover and tall fescue-white clover pastures to diverse pastures where additional grasses, legumes and herbs were added to simple grass-clover mixture. Three experiments were conducted in Canterbury, New Zealand with all pastures irrigated and grazed by dairy cows. The first study, conducted at a paddock scale, measured annual and seasonal herbage DM production, botanical composition and nutritive value of two species mixtures of perennial ryegrass (standard and high sugar) and tall fescue sown with white clover compared with more diverse mixtures where additional herbs (chicory and plantain), legumes (lucerne or red clover) and grasses (prairie grass) were added to the two species mixtures. Averaged over 2 years, annual herbage DM production was 1.6 t DM/ha greater in diverse (16.8 t DM/ha) than simple (15.2 t DM/ha) pastures, primarily reflecting greater DM production in summer. Diverse pastures had lower metabolisable energy (ME) (12.0 vs 12.2 MJ ME/kg DM) and neutral detergent fibre (301 vs 368 g/kg DM) content than simple pastures, although the total ME produced per year was greater in diverse than simple pastures (202 vs 185 GJ ME/ha). Ryegrass-based pastures had higher annual DM production (16.8 t DM/ha) than tall fescue-based pastures in the first (14.5 t DM/ha) but not second year. The second study, conducted at a small plot scale, measured annual and seasonal herbage DM production, botanical composition and nutritive value of simple and diverse pasture mixtures grazed by dairy cows subjected to full and partial irrigation. Measurements were made over two years for a simple perennial ryegrass/white clover pasture (S) and pastures with additional legumes (red clover and lucerne, SL), herbs (chicory and plantain, SH), grasses (prairie grass and timothy, SG), herbs and legumes (SLH), or herbs, legumes and grasses (SLHG) added to the simple pasture. In the partial irrigation treatment, no irrigation was applied for a 2 month period from 14 January 2011 to 10 March 2011 (Year 1) and from 7 January to 16 March 2012 (Year 2). Averaged over two years, annual herbage DM production was greater where additional legumes were added to mixtures than where additional herbs or grasses were added or in the simple mixture (16.5, 16.1, 15.1, 14.5, 14.1, 13.6 t DM/ha for SLHG, SLH, SL, SH, S and SG, respectively). The decline in DM yield associated with partial compared to full irrigation was lower in SL (10%) and SLH (14%) and SLHG (15%) than SG (19%) and S (26%) over the two year period. It was concluded that this reflected greater growth of the tap rooted legumes lucerne and red clover during the period of irrigation restriction. All pasture mixtures had similar ME content (11.1 to 11.5 MJ ME/kg DM) but mixtures containing additional legumes (SL, SLH and SHLG) had higher crude protein content (210 to 215g/kg DM) than mixtures containing additional grasses or the simple mixture (184 to 195 g/kg DM). The third study measured water use in the small plot study outlined in study two in order to investigate the production differences between full and partially irrigated pastures. Neutron probe tubes were inserted to a depth of 2.5 m and water use measured. Water use was greater in mixtures containing additional legumes (SL, SLH and SLHG, 689 mm to 705 mm) than the mixture containing additional grasses (SG, 680 mm) or the simple mixture (S, 670 mm). However, the effect was relatively small (range 14 mm to 35 mm) and was tightly linked to the summer period. In mixtures containing additional legumes (SL, SLH and SLHG), water was extracted to greater depths (0-2m) than the mixtures containing additional grasses or the simple mixture (S, SG; 0-1m). Mixtures with additional herbs (SH) extracted water to 0-1.5m soil depth. Water use efficiency (WUE) was greater in the mixtures containing additional legumes and additional herbs (SH, SL, SLH and SLHG, 18.6 to 21.1 kg DM/ha/mm) than additional grasses (SG, 17.5 kg DM/ha/mm) or the simple mixtures (S, 18.3 kg DM/ha/mm). In conclusion, the DM production and nutritive value of diverse pastures was similar or greater than that of standard perennial ryegrass/white clover pastures or tall fescue-white clover pastures. Under water restriction, DM production was less affected in mixtures containing the tap rooted legumes red clover and lucerne. Combined with the environmental benefits of diverse pastures (e.g. reduced urinary N excretion) demonstrated in other studies, it is concluded that diverse pastures are a promising alternative to perennial ryegrass-white clover pastures to deliver high production, with lower environmental implications, in dairy systems

Productivity of rotationally grazed simple and diverse pasture mixtures under irrigation in Canterbury

Herbage dry matter (DM) production, botanical composition and nutritive value were compared over 2 years under irrigation and dairy cow grazing for simple two-species grass (perennial ryegrass or tall fescue)-white clover pastures and diverse pastures where herbs (chicory and plantain), legumes (red clover and lucerne) and prairie grass were added to the simple mixtures. Averaged over 2 years, annual herbage DM production was 1.62 t DM/ha greater in diverse (16.77 t DM/ha) than simple (15.15 t DM/ha) pastures, primarily reflecting greater DM production in summer. Diverse pastures had lower metabolisable energy (ME) (12.0 vs 12.2 MJ ME/kg DM) and neutral detergent fibre (301 vs 368 g/kg DM) content than simple pastures, although the total ME produced per year was greater in diverse than simple pastures (202 vs 185 GJ ME/ha). Ryegrass-based pastures had higher annual DM production than tall fescue-based pastures in the first but not second year. The results indicate that including additional legumes and herbs with simple grass-white clover pastures may increase total DM and ME production of dairy pastures under irrigation