Forest Ecosystem Services and Human Well Being: A Sri Lankan Perspective

Having reached a critical minimum cover, Sri Lanka’s natural forests are presently under amoratorium, which has suspended any form of commercial timber extraction andmanagement for timber. Since 1989, these forests have been assigned primarily forconservation of their rich biodiversity that provides multiple benefits. Forests being a keycomponent of the island’s natural capital, they make a vital contribution to ecological serviceinfrastructure (conservation of biodiversity, water and soil, climate regulation through carbonsequestration and storage, provision of habitats for wildlife including wild germplasm,pollinators and predators of agricultural pests etc.) and in no small measure, to nature-basedtourism, for which Sri Lanka has already gained global recognition. In addition, these forestsharbour important non-wood forest products (NWFPs) that make a significant contribution tolocal economies and livelihoods, by provisioning traditional food, medicinal and/or healthcareresources, which lately are emerging even as export commodities.At a global scale, with the development of the Millennium Ecosystem Assessment, there is asignificant paradigm shift to include these ecosystem goods and environmental services in tonational accounting systems. The Rio+20 agreement and several international follow-upinitiatives advocate measures to value the contribution of ecosystems to human well-beingthrough economic-ecological and social (triple bottom line) accounting such as green GDP.Sri Lanka faces a challenge at this crucial phase of rapid development, set out in the NationalPhysical Plan 2011-2030, to engage in an emerging global initiative to drive towards agreener economy. Nonetheless, this seemingly portentous challengeopens up manyopportunities, both for research and development, to be aligned and repositioned with theevolving global scenarios in the forestry as well as other sectors, so that visionary planningnow would avoid costly remedial measures in the future. Sri Lanka is richly endowed with areligio-cultural heritage that is inextricably linked with its equally rich natural heritage. Tomove towards a greener economy, while learning from these past experiences and judiciouslyblending them with innovative thinking to suit modern situations, is indeed the task ahead ofall of us. We still have time-tested models entwined with traditional wisdom for appropriatelygreening the forestry as well as other related sectors and meeting our own sustainabledevelopment goals. The challenge now is to re-define the vision for Sri Lanka’s forests in thelight of emerging sustainable development goals, and to build the necessary in-countrycapacity to demonstrate its benefits to policymakers in our move towards a greener economy.

Changes in Edaphic Gradients across Forest-Land Use Margins in an Isolated Rainforest Remnant in the Knuckles Range, Sri Lanka

Forest fragmentation is been identified as one of the factors that initiate forest degradation.The size of the forest patch and its bordering landscape decide the severity of disturbances tothese forest patches. Moraella forest, a lowland rainforest remnant located in the KnucklesRange, is bordered by many landuse types. The present study was aimed at investigating theedaphic gradients across the forest edge bordered by different forest-landuse types viz., Pinus,grassland, tea plantation and a scrubland. Seven linear quadrates (3 m x 12 m) were laid in 3transects totaling 21 quadrates per forest-landuse category. The quadrates were positionedparallel to the forest-landuse edge and at different distances away from the edge (0, 10 and 30m towards the forest interior; 10, 30 and 50 m towards the bordering landuse type). Soilsamples (up to a depth of 5 cm) were collected from each quadrate and were bulked togetherto make a representative sample for each distance and per transect. The samples wereanalysed for available cations (Ca, Mg and K), available P, total C and N, pH using standardmethods. Data was analysed using General Linear Model (GLM) taking distance as a fixedfactor in Minitab 14.1.The results showed that soil Mg and available P showed significant differences betweendistances in forest-landuse transects while Ca and Mg concentrations showed significantdifferences between landuse types. Pair-wise comparisons revealed that the soil Mg in theforest interior was higher than that of the bordering landuse, irrespective of the type of thelanduse. Available soil P also showed a similar increase towards the forest interior. This ispossibly due to higher mycorrhizal-dependent tree species found in the forest than that in thebordering landuse types. Other chemical parameters did not show any significant differencesalong these transects. Soil Ca in the scrubland and small-holder tea plantation showedsignificantly higher concentrations compared to Pinus and it was evident in both in the forestinterior as well as in the open landuse. Higher Ca levels in the small-holder tea plantationmay be due to the use of lime to reduce soil acidity. The forest-scrubland soils showedsignificantly higher Mg levels than that of other three landuse categories. However, soil C, Nand pH showed no significant differences across these forest-landuse transects. The presentresults suggest that edaphic gradients do exist across forest-landuse transects, but with somesoil parameters. The bordering landuse type and its management practices may have someimpacts on creating such gradients.

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

Background: No studies have documented long-term trends in aboveground biomass (AGB) for mixed-dipterocarp forests (MDF), the dominant rain forest type in tropical wet equatorial Asia. In our study, we sought to document such trends over forty years across three sites representing lowland to lower montane elevations. Methods: To do this, we established fifty 100 ​m ​× ​25 ​m plots in 1978 across three sites sampled along an elevation gradient, identified as mature old-growth forest. We measured trees for diameter at breast height that we identified to species and tagged. We took wood samples to calculate species wood-specific gravity. We re-measured plots in 1998 and again in 2018. Results: We show standing AGB for all sites combined to be 517.52 ​Mg⋅ha−1 in 1978, but this declined by 17% over 40 years to 430.11 ​Mg⋅ha−1. No differences exist among sites in AGB primarily because of considerable within site variation; but interactions of time with site show declines across sites were not uniform, one remained about the same. Relatively few species represented a high proportion of the AGB with the top five species comprising between 34% and 65%, depending upon site and year sampled. One species, Mesua nagassarium, represented a disproportionately large amount of AGB and decline over time, particularly at the low elevation site. Conclusions: Our results are directly relevant to estimating AGB and standing carbon sequestered in MDF. Our study is the first to demonstrate varying but overall, declining trends in amounts of AGB among forests making predictions of biomass and standing carbon in MDF difficult over wide regions

Multispecies coexistence of trees in tropical forests: spatial signals of topographic niche differentiation increase with environmental heterogeneity

Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity

Individuals who do and do not perceive difficulties adhering to a diet for diabetes mellitus, their quality of life and glycaemic control

Opinion regarding the successful management of insulin dependent diabetes mellitus (IDDM) has identified nutrition as a key player. Whilst important, diet has also been highlighted as one of the most difficult aspects of the regimen, by both individuals with IDDM and health workers. Current dietetic recommendations for the nutritional management of individuals with IDDM include, the normalisation of plasma glucose and the promotion of patient well being. This study aimed to determine if any significant difference in quality of life (QOL) and glycaemic control existed between groups of individuals with IDDM, who perceive their diet difficult to adhere to and those who perceive adherence easy

Patterns of nitrogen-fixing tree abundance in forests across Asia and America

Symbiotic nitrogen (N)-fixing trees can provide large quantities of new N to ecosystems, but only if they are sufficiently abundant. The overall abundance and latitudinal abundance distributions of N-fixing trees are well characterised in the Americas, but less well outside the Americas. Here, we characterised the abundance of N-fixing trees in a network of forest plots spanning five continents, ~5,000 tree species and ~4 million trees. The majority of the plots (86%) were in America or Asia. In addition, we examined whether the observed pattern of abundance of N-fixing trees was correlated with mean annual temperature and precipitation. Outside the tropics, N-fixing trees were consistently rare in the forest plots we examined. Within the tropics, N-fixing trees were abundant in American but not Asian forest plots (~7% versus ~1% of basal area and stems). This disparity was not explained by mean annual temperature or precipitation. Our finding of low N-fixing tree abundance in the Asian tropics casts some doubt on recent high estimates of N fixation rates in this region, which do not account for disparities in N-fixing tree abundance between the Asian and American tropics. Synthesis. Inputs of nitrogen to forests depend on symbiotic nitrogen fixation, which is constrained by the abundance of N-fixing trees. By analysing a large dataset of ~4 million trees, we found that N-fixing trees were consistently rare in the Asian tropics as well as across higher latitudes in Asia, America and Europe. The rarity of N-fixing trees in the Asian tropics compared with the American tropics might stem from lower intrinsic N limitation in Asian tropical forests, although direct support for any mechanism is lacking. The paucity of N-fixing trees throughout Asian forests suggests that N inputs to the Asian tropics might be lower than previously thought.</p

ForestGEO: understanding forest diversity and dynamics through a global observatory network

ForestGEO is a network of scientists and long-term forest dynamics plots (FDPs) spanning the Earth's major forest types. ForestGEO's mission is to advance understanding of the diversity and dynamics of forests and to strengthen global capacity for forest science research. ForestGEO is unique among forest plot networks in its large-scale plot dimensions, censusing of all stems ≥1 cm in diameter, inclusion of tropical, temperate and boreal forests, and investigation of additional biotic (e.g., arthropods) and abiotic (e.g., soils) drivers, which together provide a holistic view of forest functioning. The 71 FDPs in 27 countries include approximately 7.33 million living trees and about 12,000 species, representing 20% of the world's known tree diversity. With >1300 published papers, ForestGEO researchers have made significant contributions in two fundamental areas: species coexistence and diversity, and ecosystem functioning. Specifically, defining the major biotic and abiotic controls on the distribution and coexistence of species and functional types and on variation in species' demography has led to improved understanding of how the multiple dimensions of forest diversity are structured across space and time and how this diversity relates to the processes controlling the role of forests in the Earth system. Nevertheless, knowledge gaps remain that impede our ability to predict how forest diversity and function will respond to climate change and other stressors. Meeting these global research challenges requires major advances in standardizing taxonomy of tropical species, resolving the main drivers of forest dynamics, and integrating plot-based ground and remote sensing observations to scale up estimates of forest diversity and function, coupled with improved predictive models. However, they cannot be met without greater financial commitment to sustain the long-term research of ForestGEO and other forest plot networks, greatly expanded scientific capacity across the world's forested nations, and increased collaboration and integration among research networks and disciplines addressing forest science