Defining guidelines for ditch depth in drained Scots pine dominated peatland forests

We used a process-based hydrological model SUSI to improve guidelines for ditch network maintenance (DNM) operations on drained peatland forests. SUSI takes daily weather data, ditch depth, strip width, peat properties, and forest stand characteristics as input and calculates daily water table depth (WTD) at different distances from ditch. The study focuses on Scots pine ( L.) dominated stands which are the most common subjects of DNM. Based on a literature survey, and consideration of the tradeoffs between forest growth and detrimental environmental impacts, long term median July–August WTD of 0.35 m was chosen as a target WTD. The results showed that ditch depths required to reach such WTD depends strongly on climatic locations, stand volume, ditch spacing, and peat thickness and type. In typical ditch cleaning areas in Finland with parallel ditches placed about 40 m apart and tree stand volumes exceeding 45 m ha, 0.3–0.8 m deep ditches were generally sufficient to lower WTD to the targeted depth of 0.35 m. These are significantly shallower ditch depths than generally recommended in operational forestry. The main collector ditch should be naturally somewhat deeper to permit water outflow. Our study brings a firmer basis on environmentally sound forestry on drained peatlands.Pinus sylvestris3–1

Peat Properties, Dominant Vegetation Type and Microbial Community Structure in a Tropical Peatland

Tropical peatlands are an important carbon store and source of greenhouse gases, but the microbial component, particularly community structure, remains poorly understood. While microbial communities vary between tropical peatland land uses, and with biogeochemical gradients, it is unclear if their structure varies at smaller spatial scales as has been established for a variety of peat properties. We assessed the abundances of PLFAs and GDGTs, two membrane spanning lipid biomarkers in bacteria and fungi, and bacteria and archaea, respectively, to characterise peat microbial communities under two dominant and contrasting plant species, Campnosperma panamensis (a broadleaved evergreen tree), and Raphia taedigera (a canopy palm), in a Panamanian tropical peatland. The plant communities supported similar microbial communities dominated by Gram negative bacteria (38.9–39.8%), with smaller but significant fungal and archaeal communities. The abundance of specific microbial groups, as well as the ratio of caldarchaeol:crenarchaeol, isoGDGT: brGDGTs and fungi:bacteria were linearly related to gravimetric moisture content, redox potential, pH and organic matter content indicating their role in regulating microbial community structure. These results suggest that tropical peatlands can exhibit significant variability in microbial community abundance even at small spatial scales, driven by both peat botanical origin and localised differences in specific peat properties.

KARAKTERISTIK LAPISAN ACROTELM DAN CATOTELM PADA GAMBUT TRANSISI DAN PEDALAMAN The Characteristic of the Acrotelm and Catotelm on the Transition and Inland Peat

ABSTRACTSince 1990s, the conversion of peatlands in Central Kalimantan from forest land cover and shrubs toagricultural land can cause the change of the characteristics of the peat. For this reason, this researchon the condition of peat properties is needed, especially the physical properties as a reference materialin the management of sustainable peatlands. This study was aims to determine the characteristics ofpeat under several land cover in the transition peat and the inland peat as well as the relationshipbetween the parameters. The research was conducted in September - December 2017, where located inWest Kanamit Village, Maliku Subdistrict and Taruna Jaya Village, Jabiren Raya Subdistrict, PulangPisau Regency, Central Kalimantan Province. The laboratory analysis at the Laboratory of Agronomyand the Laboratory of Analytical, University of Palangka Raya. Sampling in this study was uses aprofile with the size of one m2. This study was uses regression analysis and correlation methods thatare conducted to determine the pattern of relationships and the relationship between the variables ofthe physical properties of the peat. The results of the study indicate there is a similarity in the physicalproperties of the transition peat of West Kanamit Village and the inland peat of Taruna Jaya Village.The level of decomposition of peat from all locations was sapric with black to reddish black color. Theaverage values of the peat in West Kanamit Village are bulk density (0.09-0.18 g cm-3), water content(451.52-1,013.18%), fiber content (7.62-14.60%), ash content (1.73-26.15%), and organic C (42.83-57.00%). The results of the study in Taruna Jaya Village had the average values as follows as bulkdensity (0.10-0.17 g cm-3), moisture content (361.79-846.99%), fiber content (7.62-14.60 %), ashcontent (0.84-2.69%), and organic C (56.44-57.52%). Hydrophobicity in all study locations were 1.1-3.4 seconds with the WDPT method and the ratio of 0.06-0.49 with the FTIR methods. Moreover, therelationship between the peat characteristics shows a positive relationship and a negative relationship.Keyword : Acrotelm, Catotelm, Transition, Inland Peat