Cahyono Agus

Sustainable site productivity and nutrient management in a short rotation plantation of Gmelina arborea in East Kalimantan, Indonesia

AbstractSustainable Forest Management (SFM) requires information on plant growth and nutrient dynamics in forest ecosystems. To obtain fundamental information for SFM in short-rotation plantations in tropical regions, a serial study was conducted on: (i) land use changes and effects on soil chemical properties in tropical forestland, (ii) site index and nutrient dynamics in Gmelina arborea Roxb. (yemane), (iii) stand age and nutrient cycles in the first rotation of a yemane plantation on a moderately productive site, and (iv) biomass and N2-fixation of legume cover crops (LCC) for soil amelioration. Land use change from natural stands to plantations was linked to a decrease in electric conductivity (EC), cation exchange capacity (CEC), total carbon (T-C), carbon to nitrogen ratio (C/N ratio) and exchangeable ca. Three sites classified by productivity (poor, moderate and good) were examined using annual inventory data from 3 to 4% sampling intensity of yemane plantations in the Sebulu site, PT Sumalindo Lestari Jaya. The growth of yemane was very rapid during the first 6 years and was strongly influenced by site quality. The differences in average stand height between the site classes at 6 years were 3 m, representing stand volume differences of approximately 40 m3 ha−1. Whole-tree harvesting removed 50% of the aboveground biomass and nutrients. The good site had greater amounts of total phosphorus (T-P), total calcium (T-Ca), total magnesium (T-Mg), available P, and exchangeable Ca and Mg in the soil than moderate and poor sites. There were no significant differences in nutrient amounts in the soil at different stand ages (4, 6 and 8 years of age). The effects of site class on the topsoil characteristics were greater than those for land use change and stand age. Yemane plantations in tropical regions are supported more by nutrient cycling rate than by the amount of nutrient availability in soil. Nitrogen and phosphorus were the limiting nutrients for yemane growth and regeneration in East Kalimantan. Legumes can promote sustainable site productivities in short-rotation plantations in tropical forests by supplying N to the soil through N2-fixation and organic matter. Annual N2-fixation from the atmosphere by LCC was 10–60 kg N ha−1 yr−1. Application of fertilizer needs to be considered for development of yemane on very poor soils. Palabras clave: Cambios del use de la tierra, Cultivos de leguminosas, Plantación de corta rotación, Calidad de sitio, Manejo de nutrientes en bosques sustentables, Bosque tropical Resumen. Para un Manejo Forestal Sostenido (MFS) se necesita información acerca del crecimiento de las plantas y la dinámica de los nutrientes en los ecosistemas forestales. Para obtener información fundamental para el MFS en regiones tropicales de plantaciones de corta rotación, se condujeron estudios en serie acerca de (i) los cambios en la utilización de los terrenos y sus efectos en las propiedades químicas del suelo en terrenos forestales tropicales (ii) el índice de sitios y la dinámica de los nutrientes en la Gmelina arborea Roxb. (yemane) (iii) la edad de los rodales y el ciclo de los nutrientes en la primera rotación de una plantación de yemane en un sitio moderadamente productivo (iv) y estudios sobre la biomasa y fijación del N2 en cultivos con leguminosas para mejorar el suelo. El cambio en el uso de sitio bosque natural a plantaciones forestales, se relacionó con una disminución en la conductividad eléctrica, capacidad de intercambio de cationes, carbón total, tasa de carbón a nitrógeno (C/N) y el Ca intercambiable. Se examinaron tres sitios clasificados por su productividad (baja, moderada y buena), utilizando datos de un inventario anual con una intensidad de muestreo del 3-4 % de las plantaciones de yemane en el sitio Sebulu, de PT Sumalindo Lestari Jaya. El crecimiento del yemane durante los seis primeros años fue muy rápido y estuvo fuertemente influenciado por la calidad del suelo. Las diferencias en la altura promedio del rodal entre las distintas clases de sitios fue de 3 m, lo cual representa diferencias en el volumen del rodal de aproximadamente 40 m3 ha−1. La cosecha total de los árboles removió el 50% de la biomasa y de los nutrientes en la capa superior del suelo. En el sitio de buena calidad, el suelo tenía mayores cantidades de fósforo total (T-P), calcio total (T-Ca), magnesio total (T-Mg), fósforo disponible y calcio y magnesio intercambiables, que en los sitios de calidad baja o moderada. No se encontraron diferencias significativas en la cantidad de nutrientes en el suelo a las diferentes edades de los rodales (4, 6 y 8 años de edad). Los efectos de la clase de sitio en las características de la capa superficial del suelo fueron mayores que los efectos debido a los cambios de uso del terreno y por la edad del rodal. Las plantaciones de yemane en regiones tropicales, utilizan más los nutrientes reciclados que la cantidad de nutrientes disponibles en el suelo. El nitrógeno y el fósforo fueron los nutrientes limitantes en las plantaciones del oriente de Kalimantan. En plantaciones de corta rotación en bosques tropicales, las leguminosas pueden promover una productividad sostenida del sitio, al suministrarle N al suelo por medio de la fijación del N2 y de la materia orgánica. La fijación anual de N2 de la atmósfera en los cultivos con una cobertura de leguminosas fue del 10 a 60 kg N/ha/año. Para el desarrollo de plantaciones de yemane en suelos de muy baja calidad, se debe considerar la aplicación de fertilizantes.

The Role of Soil Amendment on Tropical Post Tin Mining Area in Bangka Island Indonesia for Dignified and Sustainable Environment and Life

Openly tropical tin mining in Bangka Island Indonesia expose heavy metal that had been buried became a part of our environment and life. This has become a major cause of land degradation and severe local-global environmental damages. This study aims to accelerate reconsolidation of degraded ecosystems on the former tin mine land, to increase land productivity and dignified environment through appropriate rehabilitation technology on marginal land that is inexpensive, environmentally friendly and sustainable. This study is a part of a roadmap research activities on the rehabilitation of degraded land in tropical ecosystem, that consist of (a) characterization of degraded tin mining lands through the determination of chemistry, physics, biology and mineral soil properties, (b) introducing multi-function pioneers plant for acceleration of peak pioneer plant in the reestablishment of degraded tin mining ecosystem (c) management of natural soil amendment (volcanic ash, organic waste materials and legume cover crop as a material for soil amelioration to increase land productivity, (d) role of biotechnology through the application of local bio-fertilizer (mycorrhizae, phosphate soluble bacteria, rhizobium). Soil from post tropical tin mining acid soil (pH 4.97) that dominated by sand particles (88%) with very low cation exchange capacity, very low nutrient contents (available and total-N, P, K, Ca, Mg) and high toxicity of Zn, Cu, B, Cd and Ti, but still have low toxicity of Al, Fe, Mn, Mo, Pb, As. Soil amendment of biogas and volcanic ash could improve soil quality by increasing of better pH, high available-P and cation exchange capacity and maintained their low toxicity. The growth (high, diameter, biomass, top-root ratio) of exotic pioneer plant of Kemiri sunan (Reutealis trisperma) increased in the better soil quality that caused by application of proper soil amendment. The grand concept and appropriate technology for rehabilitation of degraded tin-mining land ecosystems in tropical regions which are the lungs of the world have a high contribution for development of our dignified and sustainable environment and life.

Development of Landscape Architecture through Geo-eco-tourism in Tropical Karst Area to Avoid Extractive Cement Industry for Dignified and Sustainable Environment and Life

Karst areas in Indonesia amounted to 154,000 km2, potentially for extractive cement and wall paint industries. Exploitation of karst caused serious problems on the environment, health and social culture of the local community. Even though, karst region as a natural and cultural world heritage also have potential environmental services such as water resources, carbon sink, biodiversity, unique landscapes, natural caves, natural attractions, archaeological sites and mystic areas. Landscape architectural management of in the concept of blue revolution through the empowerment of land resources (soil, water, minerals) and biological resources (plant, animal, human), not only have adding value of economy aspect but also our dignified and sustainable environment and life through health, environmental, social, cultural, technological and management aspects. Geo-eco-tourism offers the efficiency of investment, increased creative innovation, increased funding, job creation, social capital development, stimulation of the socio-entrepreneurship in community. Community based geo-eco-tourism in Gunung Kidul Yogyakarta rapidly growing lately due to the local government banned the exploitation of karst. Landscape architecture at the caves, white sand beaches, cliffs in karst areas that beautiful, artistic and have special rare natural architecture form of stalactite and stalagmite, become the new phenomenal interested object of geo-eco-tourism. Many hidden nature objects that had been deserted and creepy could be visited by many local and foreign tourists. Landscape architectural management on hilltops with a wide view of the universe and fresh, sunset and sunrise, the clouds country are a rare sight for modern community. Local cultural attractions, local culinary, home stay with local communities will be an added attraction, but the infrastructure and human resources should be developed. Traveler photographs that widespread rapidly through social media and mass media became a great and effective promotion. With geo-eco-tourism, people can empowering natural resource to gain harmonization of economic, environment and social-culture aspect, without destroy it.

Development of Blue Revolution Through Integrated Bio-cycles System on Tropical Natural Resources Management

The high net primary production in tropical ecosystem were more supported by the rapid organic-cycling than their low fertility weathered acid soil, due to the high temperature, rainfall, moisture and light intensity along a year. Tropical natural resources have a high biomass productivity but still less economical values. New paradigm from extraction to empowerment of natural resource will give new challenge to shift from red- & green economic to blue economic concept that should be more smart, global, focus, and futuristic for sustainable development. Integrated Bio-cycle System (IBS) is a closed-to-nature ecosystem on landscape ecological management to manage land resource (soil, mineral, water, air, microclimate), biological resources (flora, fauna, human) and their interaction to have more high added value in environment, economic, socio-culture and health aspect. The bio-economic chain should be managed through 9A (Agro-production, -technology, -industry, -business, -distribution, -marketing, -infrastructure, -management, -tourism) with 9R (reuse, reduce, recycle, refill, replace, repair, replant, rebuild, reward).The system has multifunction and multi-product, that will meet with the expected basic need for daily-, monthly-, yearly- and decade’s income at short-, medium- and long- term periods for small, medium, and big stakeholder. IBFS can produce “gold of life”, such as: yellow gold (food, rice, corn), green gold (vegetables), brown gold (plantation wood), red gold (meat), white gold (milk, fish), black gold (organic fertilizer), transparent gold (water), gas gold (oxygen), blue gold (biogas, biomass energy, bio fuel), king gold (herbal medicine), prosperity gold (tourism), inner gold (mystic). IBS with ABCG (academic, business, community, government) networking has a good prospect for sustainable environment and life.

The Impact of Forest Fire on the Biodiversity and the Soil Characteristics of Tropical Peatland

Land use change and forest fire covering millions ha of peat-land in Central Kalimantan are the main factor contribute on forest peatland degradation. This study aimed to determine the impact of forest peatland fire severity level on the plant diversity and soil chemical properties of wet tropical peatland in Central Kalimantan, Indonesia. The severe peat fire extremely decreased diversity, number of individuals as well as number of plant species. The accumulation of ashes in forest peat fires impacted area instantly increased pH, organic matter, humic acid content, hydrophobicity, available-N and available-K. However, their availabilities had only been temporary as they were easily diminished and washed way which result in long-term land degradation. An opened and dried peatland had low water holding capability and, hence, it was relatively easy to burn during the dry season but flooded during the rainy season. Tropical forest peats fires significantly reduced plant diversity and changed soil chemical properties. This forest peat fire potentially loss its function, particularly moisture storage, carbon, nutrients and biodiversity.