| 1. |
- Axelsson, Petter, et al.
(författare)
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Lessons learned from 25 years of operational large-scale restoration: The Sow-A-Seed project, Sabah, Borneo
- 2024
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Ingår i: Ecological Engineering. - 0925-8574 .- 1872-6992. ; 206
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Tidskriftsartikel (refereegranskat)abstract
- While restoration projects globally scale-up to meet the growing demand to restore degraded ecosystems, data on the long-term benefits of restoration are still rare. Here, we describe the lessons learned from the Sow-A-Seed project in Sabah, Borneo: a long-term and large-scale restoration project launched in 1998 with the aim to rehabilitate 18,500 ha of tropical rainforest degraded by logging and forest fires. The project was built from the ground-up, including establishment of essential infrastructure and knowledge creation via trial-and-error. Three restoration techniques were used depending on the level of degradation; 1) Assisted Natural Regeneration (weeding, climber cutting and selective girdling) to promote natural regeneration of late-successional species in the least disturbed forests, and; 2) Enrichment Planting in gap-clusters in moderately disturbed forests, and; 3) Enrichment Planting in rows (i.e, line-planting) throughout heavily degraded forests with no- or few late successional tree species in the overstory. The project includes successful propagation of 92 native tree species including dipterocarps and fruit trees, and planting of over 5 million trees during the last 25 years. Long-term monitoring shows that the mortality rate of planted seedlings is -15% per year up to 3 years, but decreases to -2% between years 3-10 and 10-20. One of the largest trees, a Shorea leprosula planted in 1998, is now 74 cm in DBH and some planted trees have reached reproductive age and are contributing to natural regeneration. A range of wildlife including orangutans, elephants, hornbills and all five wildcat species in Sabah have been documented in the area. In 2015, the area was classified as a Class 1 protected forest, the highest level of conservation status in Malaysia, and removed from commercial forestry. We highlight that there is much knowledge to be gained by research dove-tailing with operational activities, and we encourage that the lessons learned from operational restoration are shared among practitioners and restoration ecologists. We present 8 key lessons learned from the Sow-a-Seed project.
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| 2. |
- Axelsson, Petter, et al.
(författare)
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Mega El Niño's change the playing field for culturally important tree species and hence the foundation for human-nature interactions in tropical forests
- 2021
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Ingår i: Trees, Forests and People. - : Elsevier BV. - 2666-7193. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Humans have interacted with trees for millennia and the strength of such interactions determines the long-term social values of trees and forests. Such ecocultural linkages could be important to promote during reforestation efforts, potentially helping to turn the tide on the current rapid extinction of cultural and biological diversity. In addition, predicting the fate of ecoculturally important species to changing climates may help guide tree species selection best-suited to future climates. We assessed the vulnerability of four ecoculturally important tree species native to Southeast Asia to an extreme drought: Koompassia excelsa, Nephelium lappaceum, Shorea fallax and Shorea leprosula. These species provide distinct and unique products, and Koompassia excelsa is well-represented in local mythological stories and considered a Cultural Keystone Species (CKS). We used two complementary approaches: 1) an experimental common garden and 2) naturally occurring wild trees growing in a secondary forest and compared the performance of trees before, after, and during the 2016 El Niño event with record breaking low precipitation and high temperatures. We found that mortality of the CKS K. excelsa in the common garden, along with mortality and growth of wild trees were unaffected by the El Niño drought. In contrast, young trees of N. lappaceum and S. fallax planted in the common garden had mortality 4 and 3 times higher, respectively, during the El Niño drought compared to normal years. Growth rate of S. fallax in the wild was also significantly lower during the El Niño drought and this effect was particularly pronounced in highly disturbed forests. Our results demonstrate that the impact of extreme climatic events, that are predicted to become more common with climate change, on culturally important tree species is species specific. Management of such species may thus need species specific measures to maintain viable populations and hence provide the basic physical settings for human-nature interactions and associated cultural identities to persist. In this context, our findings that cultural keystone species such as K. excelsa could be drought tolerant is noteworthy, as investing on such species could prove to be beneficial for both local cultures and conservation of native ecosystems and biodiversity.
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| 3. |
- Falck, Jan, et al.
(författare)
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The Forest Observation System, building a global reference dataset for remote sensing of forest biomass
- 2019
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS- based biomass products while developing new synergies between the RS and ground-based ecosystem research communities.
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| 4. |
- Lussetti, Daniel, et al.
(författare)
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Soil Carbon Pool and Carbon Fluxes Estimation in 26 Years after Selective Logging Tropical Forest at Sabah, Malaysia
- 2022
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Ingår i: Forests. - : MDPI AG. - 1999-4907. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- The soil carbon pool holds an enormous amount of carbon, making it the largest reservoir in the terrestrial ecosystem. However, there is growing concern that unsustainable logging methods damage the soil ecosystem, thus triggering the release of soil carbon into the atmosphere hence contributing to ongoing climate change. This study uses a replicated (n = 4) logging experiment to examine the impact of supervised logging with climber cutting (SLCC) and conventional logging (CL) on basic soil characteristics, litter input to soils, soil carbon pools, and soil respiration in a mixed dipterocarp forest 26 years after logging. This study found that there was no significant difference observed in the soil physicochemical properties and total carbon pools between the logging treatments and the virgin forest. Soil carbon pools dominated the total carbon pools, and the highest mean value was recorded in SLCC (87.95 +/- 13.67 Mg C ha(-1)). Conventional logging had a lower mean value (71.17 +/- 12.09 Mg C ha(-1)) than virgin forest (83.20 +/- 11.97 Mg C ha(-1)). SLCC also shows a higher value of soil respiration rate (161.75 +/- 21.67 mg C m(-2) h(-1)) than CL (140.54 +/- 12.54 mg C m(-2) h(-1)). These findings highlight the importance of accurate quantification of the effect of different logging methods on the forest's carbon pools.
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| 5. |
- Lussetti, Daniel, et al.
(författare)
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Soil physico-chemical properties in a selectively logged forest at Gunung Rara. Forest Reserve, Sabah, Malaysia
- 2023
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Ingår i: Journal of Sustainability Science and Management. - 2672-7226. ; 18, s. 73-86
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Tidskriftsartikel (refereegranskat)abstract
- The tropical rainforest has various lists of crucial functions in forest productivity. However, unsustainable logging method has led to the decline of soil fertility in the forest. This study aimed to investigate the impacts of different logging methods on the soil’s physical and chemical properties at Gunung Rara Forest Reserve, Sabah, Malaysia. The logging treatments were supervised logging with climber cutting (SLCC) and conventional logging (CL), and a virgin forest (VF) was used as the control plot. The size for each plot was one hectare and each was replicated into four plots making the total plots 12. Soil sampling was done at four depths (0–10 cm, 10–20 cm, 20–50 cm, and 50–100 cm) for soil analysis and bulk density. The finding shows that the soil properties in the treatment plots were not significantly different from the untreated plot. The soil organic matter, total nitrogen, and total carbon decreased with soil depths. The soil in all study areas was found acidic, ranging from 4.12 to 4.46. The soil textures were clay, sandy clay loam, and sandy loam. The SLCC plot recorded a higher mean of soil organic matter (5.93–7.40%), total phosphorus (0.08–0.09 meq/100 g), and cation exchange capacity (5.69–7.05 meq/100 g) compared to other plots. This study highlights the importance of analysing the impact of different logging methods on the soil’s physicochemical properties
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| 6. |
- Lussetti, Daniel, et al.
(författare)
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Supervised logging and climber cutting improves stand development: 18 years of post-logging data in a tropical rain forest in Borneo
- 2016
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 381, s. 335-346
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Tidskriftsartikel (refereegranskat)abstract
- We analyzed 18 years of post-logging data from Sabah, Borneo to evaluate the impact of two selective logging methods - Supervised logging (SL) including pre-aligned skid trails and directional felling, and conventional logging (CL), where trees were felled before the crawler tractor was called in for skidding and the fellers had no formal training in felling techniques - on net standing volume recovery, survivor growth, ingrowth and mortality of trees (>= 10 cm DBH). The logging treatments were either combined with- (CC) or without (NCC) pre-harvest climber cutting in a randomized 2 x 2 factorial design consisting 16 one-hectare treatment plots. We investigated the effect on the complete stand including all trees (>= 10 cm DBH) regardless of species, but also distinguished between the effects on the commercially interesting species of dipterocarps (Dipterocarpaceae family) and pioneer species (mainly Macaranga species). Supervised logging in combination with climber cutting was in many ways beneficial to stand development and these effects were mainly expressed at higher harvest intensities. For example, supervised logging reduced the ingrowth and survivor growth of pioneer Macaranga spp.; at high harvest intensities approximately 50% fewer pioneers grew in when SL was used in comparision to CL. In addition, climber cutting increased the ingrowth as well as decreased the mortality of highly valuable dipterocarp species with increasing harvest intensity. These effects appeared also to have stand level consequences as forests treated with the combination of supervised logging and climber cutting also exhibited faster recovery in standing volume of high value dipterocarps compared to any other combination of treatments. We conclude that, with improved ingrowth of dipterocarps, reduced overall mortality and generally better stand volume recovery; supervised logging (SL) in combination with climber cutting (CC) could be an attractive forest management system in mixed dipterocarp forests. (C) 2016 Elsevier B.V. All rights reserved.
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| 7. |
- Lussetti, Daniel, et al.
(författare)
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Using linear mixed models to evaluate stand level growth rates for dipterocarps and Macaranga species following two selective logging methods in Sabah, Borneo
- 2019
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 437, s. 372-379
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Tidskriftsartikel (refereegranskat)abstract
- To understand and predict the dynamics and productivity of the world's tropical rainforests after logging is a major challenge for ecologists and forest managers. Realistic forest-dynamics models for this biome are largely lacking. Using linear mixed models, we analyse basal area development for the commercially valuable tree species of dipterocarps and the fast-growing pioneer Macaranga spp., following two selective logging methods; supervised logging (SL) and conventional logging (CL) combined with- or without pre-harvest climber cutting (SLC and SL, and CLC and CL, respectively). After logging there was an initial period of about five years before recovery started. During the 18-year study period, the average stand basal area growth rates of the dipterocarp group in the SLC treatment was double that in the CL treatment, revealing a faster recovery. Eighteen years after logging, SL and SLC treatments recovered 93% and 84%, respectively, of the initial standing dipterocarp basal area, compared to 73% and 72% recovery for the CL and CLC treatments. SLC treatments reduced the overall establishment of pioneer species (Macaranga spp.) by about 45% in contrast to CL and CLC treatments. Our study provides a framework for evaluating and comparing growth rates in tropical forests for different logging methods. The results suggest that a combination of directional felling, pre-aligned skid trails and pre-harvest climber cutting can improve future yields in tropical rainforests.
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| 8. |
- Mobley, Kenyon B., et al.
(författare)
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Morphological and genetic divergence in Swedish postglacial stickleback (Pungitius pungitius) populations
- 2011
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Ingår i: BMC Evolutionary Biology. - London : BioMed Central. - 1471-2148. ; 11, s. 287-
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Tidskriftsartikel (refereegranskat)abstract
- Background: An important objective of evolutionary biology is to understand the processes that govern phenotypic variation in natural populations. We assessed patterns of morphological and genetic divergence among coastal and inland lake populations of nine-spined stickleback in northern Sweden. Coastal populations are either from the Baltic coast (n = 5) or from nearby coastal lakes (n = 3) that became isolated from the Baltic Sea (< 100 years before present, ybp). Inland populations are from freshwater lakes that became isolated from the Baltic approximately 10,000 ybp; either single species lakes without predators (n = 5), or lakes with a recent history of predation (n = 5) from stocking of salmonid predators (~50 ybp).Results: Coastal populations showed little variation in 11 morphological traits and had longer spines per unit of body length than inland populations. Inland populations were larger, on average, and showed greater morphological variation than coastal populations. A principal component analysis (PCA) across all populations revealed two major morphological axes related to spine length (PC1, 47.7% variation) and body size (PC2, 32.9% variation). Analysis of PCA scores showed marked similarity in coastal (Baltic coast and coastal lake) populations. PCA scores indicate that inland populations with predators have higher within-group variance in spine length and lower within-group variance in body size than inland populations without predators. Estimates of within-group PST (a proxy for QST) from PCA scores are similar to estimates of FST for coastal lake populations but PST > FST for Baltic coast populations. PST > FST for PC1 and PC2 for inland predator and inland no predator populations, with the exception that PST < FST for body size in inland populations lacking predators.Conclusions: Baltic coast and coastal lake populations show little morphological and genetic variation within and between groups suggesting that these populations experience similar ecological conditions and that time since isolation of coastal lakes has been insufficient to demonstrate divergent morphology in coastal lake populations. Inland populations, on the other hand, showed much greater morphological and genetic variation characteristic of long periods of isolation. Inland populations from lakes without predators generally have larger body size, and smaller spine length relative to body size, suggesting systematic reduction in spine length. In contrast, inland populations with predators exhibit a wider range of spine lengths relative to body size suggesting that this trait is responding to local predation pressure differently among these populations. Taken together the results suggest that predation plays a role in shaping morphological variation among isolated inland populations. However, we cannot rule out that a causal relationship between predation versus other genetic and environmental influences on phenotypic variation not measured in this study exists, and this warrants further investigation.
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