Early Effects of Fertilizer and Herbicide Reduction on Root-Associated Biota in Oil Palm Plantations

To secure high yield, tropical oil palm plantations are fertilized, and understory vegetation is controlled by chemical clearing with herbicides. These treatments cause a drastic turnover of soil microbes and cause loss of beneficial mycorrhizal fungi. Here, we tested if reduced fertilization and weeding instead of conventional treatments restored beneficial ecological groups associated with roots. We conducted our study one year after the start of the reduced management in large-scale oil palm plantations. We hypothesized that reduced fertilizer application and weeding result in shifts of the root-associated species composition because changes in the management regimes affect belowground biomass and nutrients in soil and roots. Alternatively, we hypothesized that the legacy of massive soil fertilization and herbicide application preclude compositional shifts of root-associated biota within short time periods. We did not find any significant treatment effects on root nutrient contents, root biomass, and nutrients in soil. At the level of species (based on operational taxonomic units obtained by Illumina sequencing) or phyla, no significant effects of reduced management were observed. However, distinct functional groups showed early responses to the treatments: nematodes decreased in response to weeding; yeasts and ectomycorrhizal-multitrophic fungi increased under fertilizer treatments; arbuscular mycorrhizal fungi increased under fertilizer reduction. Since the responsive ecological groups were represented by low sequence abundances, their responses were masked by very high sequence abundances of saprotrophic and pathotrophic fungi. Thus, the composition of the whole root-associated community was unaffected by reduced management. In conclusion, our results show that changes in management regimes start to re-wire critical constituents of soil–plant food webs.

Bee diversity in fragmented areas of Volcano Etna (Sicily, Italy) at different degrees of anthropic disturbance (Hymenoptera: Apoidea, Anthophila)

The present three-year study traces the diversity of four bee communities in fragmented pedemontane areas of Volcano Etna (Catania province, Sicily) near the Metropolitan City of Catania, under different land management regimes. The selected areas comprise two different urban parks within Catania (Parco Gioeni and Parco degli Ulivi), a Nature Reserve (Complesso Immacolatelle e Micio Conti, San Gregorio di Catania), and an agroecosystem (a citrus orchard, Aci Catena). Previous data obtained from a well-investigated area (Leucatia, north of Catania) have been used as a control for bee diversity for this study. The results include an outline of bee species richness, data on the composition of bee communities, and seasonal patterns, using several diversity indexes. The study of bee diversity shows a total of 163 species, arranged in five families. The four investigated locations include 104 species arranged in four families: Andrenidae (20 species), Halictidae (15 species), Megachilidae (31 species), and Apidae (38 species); with a similar number of species (102) recorded in the control site (Leucatia). The study highlights strong seasonal variations of bee communities in all investigated sites, with differentiated seasonal patterns, whose compositions are affected mainly by forage sources, suitable nesting sites, as well as human activities. The data obtained provide a rough but basilar framework to assess management strategies to maintain adequate levels of bee diversity, especially for those areas with moderate to high environmental fragmentation. Our findings highlight the importance of season-long sampling of bee population factors if used as indicators in ecological studies.

HARVESTER PRODUCTIVITY AND COSTS IN CLEAR CUTTING Pinus taeda STANDS UNDER DIFFERENT MANAGEMENT REGIMES

The increased demand for several forest products makes it necessary to apply different management regimes in forest stands, which may influence the wood harvesting operations. This study aimed to evaluate the effect of average individual tree volumes obtained through different management regimes on harvester productivity and costs, thereby enabling to generate information for forest managers. The study was carried out in three Pinus taeda L. stands under clear cutting with different average individual tree volumes (AIV): I (0.367 m3); II (0.582 m3); and III (0.766 m3). Working cycle times, productivity per productive machine hour, energy yield and production costs were obtained by a time and motion study, in which the average values obtained were compared by the Tukey-Kramer test (α ≤ 0.05). The work elements of the harvester’s work cycles were affected by forest management regimes, mainly the movement and the processing, with significant statistical difference between stands, but no difference between total working cycle times. The management regime applied to forest stands influenced the spacing and whole trunk volume which consequently increased the average productivity of the machine from 36.8 to 74.1 m³ per productive machine hour in treatments I and III, respectively, and reduced production costs by 50%. The forest management regimes influenced the clear-cutting operation with harvester.

Management diversification increases habitat availability for multiple biodiversity indicator species in production forests

Context Forest biodiversity is closely linked to habitat heterogeneity, while forestry actions often cause habitat homogenization. Alternative approaches to even-aged management were developed to restore habitat heterogeneity at the stand level, but how their application could promote habitat diversity at landscape scale remains uncertain. Objectives We tested the potential benefit of diversifying management regimes to increase landscape-level heterogeneity. We hypothesize that different styles of forest management would create a diverse mosaic of forest habitats that would in turn benefit species with various habitat requirements. Methods Forest stands were simulated under business-as-usual management, set-aside (no management) and 12 alternative management regimes. We created virtual landscapes following diversification scenarios to (i) compare the individual performance of management regimes (no diversification), and (ii) test for the management diversification hypothesis at different levels of set-aside. For each virtual landscape, we evaluated habitat availability of six biodiversity indicator species, multispecies habitat availability, and economic values of production. Results Each indicator species responded differently to management regimes, with no single regime being optimal for all species at the same time. Management diversification led to a 30% gain in multispecies habitat availability, relative to business-as-usual management. By selecting a subset of five alternative management regimes with high potential for biodiversity, gains can reach 50%. Conclusions Various alternative management regimes offer diverse habitats for different biodiversity indicator species. Management diversification can yield large gains in multispecies habitat availability with no or low economic cost, providing a potential cost-effective biodiversity tool if the management regimes are thoughtfully selected.

Influences of fisher attitudes and behaviour on regulation non-compliance: A case study from the Marlborough Sounds, New Zealand recreational blue cod fishery

<p>Although it has been noted that fisheries is 90% managing people, most management regimes focus solely on the other 10%; the biological aspect. Furthermore, despite the growing popularity of recreational fishing and increased awareness of its biological effects, there exists even less literature on the human dimensions in this domain than in commercial fisheries. In New Zealand, the Marlborough Sounds recreational blue cod fishery is strictly regulated, due to its popularity and a top-down management regime, with limited fisher involvement. Despite substantial biological information on the fishery, there is only one piece of human dimensions research, carried out before the current management regime came into force. This thesis responds to calls for greater integration of human behaviour into fisheries analyses and management. Specifically, the aim is to explore fisher attitudes towards and compliance with the fishery regulations. The research presented here is a combination of intercept and online surveys of over 500 fishers and is interdisciplinary in nature. Four related studies, aimed towards publication, provide important insights for a more inclusive management style in the future. The first chapter examines fisher attitudes and the factors shaping them, a poorly understood area. Responses reveal that although overall, fishers were dissatisfied with the current regulations, inexperienced and non-locally-resident fishers display more positive attitudes towards the regulations. The second core chapter examines regulation non-compliance, a worldwide fisheries problem that can undermine the effectiveness of a management regime. As rule-breaking behaviour is often a sensitive behaviour, two indirect methods (Randomized Response and Item Count) are tested against direct questioning in estimating violations of three recreational blue cod fishing regulations. Results show mixed effectiveness for the indirect methods, with a significantly higher estimate of non-compliance estimate obtained for only one of the three regulations. The third core chapter uses structural equation modeling to examine the drivers of non-compliance with the size and daily limits for blue cod. Knowledge of these drivers is essential to increasing voluntary compliance with the regulations and these results demonstrate that social norms are the largest influence for both the regulations. Finally, the fourth core chapter examines the potential effects of the maximum size limit on the number of blue cod discarded as well as fisher satisfaction and compliance. A scenario approach reveals that either increasing or eliminating the maximum size limit could offer significant gains compared with the control scenario. The four chapters contribute to the global literature on subjects including fisher attitudes, estimating sensitive behaviours, drivers of non-compliance, discards in recreational fisheries and natural resource management. Taken together, the results reaffirm the benefits of including the human dimensions in fisheries management regimes. For the Marlborough Sounds recreational blue cod fishery, a shift away from the current, top-down and biologically focused management regime is suggested. I also argue that a more inclusive management strategy may be the best chance for success and allow the fishery to be saved for future generations; a goal shared by both fishers and management.</p>

Influences of fisher attitudes and behaviour on regulation non-compliance: A case study from the Marlborough Sounds, New Zealand recreational blue cod fishery

<p>Although it has been noted that fisheries is 90% managing people, most management regimes focus solely on the other 10%; the biological aspect. Furthermore, despite the growing popularity of recreational fishing and increased awareness of its biological effects, there exists even less literature on the human dimensions in this domain than in commercial fisheries. In New Zealand, the Marlborough Sounds recreational blue cod fishery is strictly regulated, due to its popularity and a top-down management regime, with limited fisher involvement. Despite substantial biological information on the fishery, there is only one piece of human dimensions research, carried out before the current management regime came into force. This thesis responds to calls for greater integration of human behaviour into fisheries analyses and management. Specifically, the aim is to explore fisher attitudes towards and compliance with the fishery regulations. The research presented here is a combination of intercept and online surveys of over 500 fishers and is interdisciplinary in nature. Four related studies, aimed towards publication, provide important insights for a more inclusive management style in the future. The first chapter examines fisher attitudes and the factors shaping them, a poorly understood area. Responses reveal that although overall, fishers were dissatisfied with the current regulations, inexperienced and non-locally-resident fishers display more positive attitudes towards the regulations. The second core chapter examines regulation non-compliance, a worldwide fisheries problem that can undermine the effectiveness of a management regime. As rule-breaking behaviour is often a sensitive behaviour, two indirect methods (Randomized Response and Item Count) are tested against direct questioning in estimating violations of three recreational blue cod fishing regulations. Results show mixed effectiveness for the indirect methods, with a significantly higher estimate of non-compliance estimate obtained for only one of the three regulations. The third core chapter uses structural equation modeling to examine the drivers of non-compliance with the size and daily limits for blue cod. Knowledge of these drivers is essential to increasing voluntary compliance with the regulations and these results demonstrate that social norms are the largest influence for both the regulations. Finally, the fourth core chapter examines the potential effects of the maximum size limit on the number of blue cod discarded as well as fisher satisfaction and compliance. A scenario approach reveals that either increasing or eliminating the maximum size limit could offer significant gains compared with the control scenario. The four chapters contribute to the global literature on subjects including fisher attitudes, estimating sensitive behaviours, drivers of non-compliance, discards in recreational fisheries and natural resource management. Taken together, the results reaffirm the benefits of including the human dimensions in fisheries management regimes. For the Marlborough Sounds recreational blue cod fishery, a shift away from the current, top-down and biologically focused management regime is suggested. I also argue that a more inclusive management strategy may be the best chance for success and allow the fishery to be saved for future generations; a goal shared by both fishers and management.</p>

Creating Commons: Reflections on Creating Natural Resource Management Regimes in South Sulawesi, Indonesia

Thirteen years ago, PAYOPAYO Peasant School Network, an Indonesian community organizing network based in Sulawesi, facilitated Participatory Action Research (PAR) that eventually culminated in a creation of a common resource management regime around an irrigation system for agricultural use in Tompobulu, a village within a national park in upland South Sulawesi. This note from the field presents a reflection on collective action experiences of a community in building the commons in 2008 to 2009, and revisits the extent to which the commons has been managed, how management regimes changed over time, and how it survives as a commons today. The initial factors allowing for establishment of the commons, understood here as a social practice toward common goals, were a shared need for water (local needs & conditions), and the success to make use of the irrigation commons as a means to initiate other collective actions. Drawing from concerted engagement and analysis conducted in 2021, this note revisits the key factors and highlights different ways the commons continues to persist, namely due to the distinct benefits felt by participants, the existence of institutions that regulate the use and maintenance of the commons, the existence of a monitoring system among members, participation of members in formulating and modifying the rules, and the recognition of National Park authorities on the commons and its rules.