Trees, Forests and People最新文献

{"title":"Influence of stand characteristics and management activities on aboveground carbon storage in Japanese cedar and cypress plantations: Sustainable management implications","authors":"Kyaw Win ,&nbsp;Tamotsu Sato","doi":"10.1016/j.tfp.2024.100702","DOIUrl":"10.1016/j.tfp.2024.100702","url":null,"abstract":"<div><div>Tree plantations substantially sequester carbon in aboveground biomass and soil and serve as an alternative to forests in mitigating global warming. This study investigated the relationship between aboveground carbon and stand characteristics and management activities in two Japanese plantations (cedar and cypress) for their sustainable management viewpoint, which has not been studied before. Aboveground carbon stock ranged from 3.96 to 248.53 Mg C ha^-1 in 9- to 188-year-old Japanese cedar and 7.09 to 119.17 Mg C ha^-1 in 11- to 129-year-old Japanese cypress plantations. Annual aboveground carbon storage differed significantly between the two species. Aboveground carbon storage in Japanese cedar was affected by stand characteristics (e.g. soil moisture, electrical conductivity, soil texture especially sand and clay, site quality, and stem density) and management activities (e.g. initial silvicultural practices, stem exclusion practices, pest and wildlife management and land management). However, the same in Japanese cypress was affected by stand characteristics (e.g. soil moisture, electrical conductivity, soil texture especially sand, bulk density, site quality, stem density, and elevation) along with management activities (e.g. initial silvicultural practices, stem exclusion practices and land management). Therefore, continuous monitoring and periodic assessment of the stand characteristics and management activities may be taken into consideration in future policy-making decisions to promote aboveground carbon storage and climate change mitigation ability of these plantations in Japan on a sustained basis.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100702"},"PeriodicalIF":2.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shifts in soil quality from degradation to early phase of forest restoration: Evidence from Rohingya refugee camps, Cox's Bazar, Bangladesh","authors":"Hossain Mahmood ,&nbsp;Chameli Saha ,&nbsp;Sanjoy Saha ,&nbsp;Md. Seikh Sadiul Islam Tanvir ,&nbsp;SM Nuhas Hossain Sakal","doi":"10.1016/j.tfp.2024.100701","DOIUrl":"10.1016/j.tfp.2024.100701","url":null,"abstract":"<div><div>Rohingya influx in Bangladesh destructed about 3200 ha of the reserved forest of Cox's Bazar South Forest Division for the construction of housing, other utilities, and firewood collection. To reduce soil erosion, the degraded sites were intervened with different slope management initiatives (without terrace, earthen terrace, bamboo terrace). Restoration initiatives were intensified in 2019 and 291.90 ha of degraded forest areas were brought under plantation. A soil quality baseline study was conducted in 2020. The present study monitored the changes in soil properties (bulk density, organic carbon, electrical conductivity, total nitrogen, available phosphorus, and potassium) after four years in the restored sites. Comparatively, higher bulk density (1.61±0.03 g/cm3) and organic carbon (2.45±0.09 %) were observed for the control site soil and bamboo terrace, respectively. Similar pH (4.94±0.07 to 5.14±0.14) and Electrical Conductivity (EC) (109.99±38.17 µS/cm to 122.60±13.13 µS/cm) were observed for the soil of all slope management interventions. In the case of nutrients, higher concentrations of total nitrogen (0.09 %) and available potassium (94.79±22.63 µg/g) were detected for the soil of the bamboo terrace. Similar concentrations of available phosphorus were observed for all slope management interventions. The present study showed a significant (P(<em>T</em>&lt;=<em>t</em>) two-tail) higher content of organic carbon and EC than the baseline study. At the same time, phosphorus and potassium concentrations dropped significantly (P(<em>T</em>&lt;=<em>t</em>) two-tail) compared to the baseline.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100701"},"PeriodicalIF":2.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of carbon stocks of woody plant species in church forests of West Gojjam zone, Northwestern Ethiopia: Implications for climate change mitigation","authors":"Abebe Ayele Haile ,&nbsp;Ali Seid ,&nbsp;Amare Bitew Mekonnen ,&nbsp;Wubetie Adnew ,&nbsp;Getahun Yemata ,&nbsp;Endalamaw Yihune ,&nbsp;Animut Mekuriaw","doi":"10.1016/j.tfp.2024.100704","DOIUrl":"10.1016/j.tfp.2024.100704","url":null,"abstract":"<div><div>Forests, particularly church forests, play a crucial role in mitigating climate change by absorbing and storing CO₂, preserving biodiversity, and acting as carbon sinks. This study aimed to estimate the biomass and carbon stocks of various woody species in church forests in the West Gojjam zone. Twenty-six church forests were selected based on agroecology, elevation, size, and proximity to population centers. Vegetation data were collected using a systematic sampling technique, with 20 m x 20 m (400 m²) plots established along transect lines oriented at 120° intervals at 60°, 180°, and 300° within each church forest. Measurements of diameter at breast height (DBH) and height were taken for all matured woody plants with a DBH ≥ 2.5 cm. Data analysis was performed using one-way ANOVA to evaluate the effects of altitude, forest size, and human disturbance on aboveground biomass (AGB) and carbon stocks. Additionally, linear regression was applied to investigate the relationship between vegetation structure (species richness, density, and diversity) and biomass accumulation. The results revealed a total of 111 woody species, dominated by indigenous species particularly from the Fabaceae family. The study church forests had Shannon diversity index and richness ranging from 1.73 to 3.47 and 7 to 45, respectively. The results showed that the 26 church forests had an average aboveground biomass (AGB) of 31.97 ± 3.31 tons ha^-1 and a CO₂ equivalence of 97.15 ± 10.47 tons ha^-1. The AGB and aboveground carbon (AGC) values varied among the church forests, of which Debre Mihret Mesk Kidanemihret had the highest AGB with 99.00 tons ha^-1 and 49.50 tons ha^-1 AGC, indicating their substantial capacity for carbon storage. Conversely, Korch Silassie church forest displayed the lowest AGB, suggesting ecological challenges that necessitate targeted conservation efforts. These findings underscore the critical role of church forests as carbon sinks, capable of sequestering atmospheric CO₂ and contributing to the mitigation of climate change. The findings of the present study suggest the integration of church forests into national and international climate policies, such as REDD+ to leverage their potential in reducing emissions from deforestation and forest degradation.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100704"},"PeriodicalIF":2.7,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142437833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The use of digital tools in forest tourism and recreation - Experiences from Warsaw agglomeration in Poland","authors":"Natalia Korcz ,&nbsp;Mariusz Ciesielski ,&nbsp;Agnieszka Kamińska ,&nbsp;Kamil Choromański ,&nbsp;Dariusz Gotlib ,&nbsp;Fruzsina Stefán ,&nbsp;Karolina Taczanowska","doi":"10.1016/j.tfp.2024.100697","DOIUrl":"10.1016/j.tfp.2024.100697","url":null,"abstract":"<div><div>Tourism and recreation in forest areas around large urban agglomerations are becoming increasingly important and pose major management challenges in terms of sustainability, environmental impact and balancing the needs of visitors with conservation efforts. Digital tools are critical to the planning and management of suburban forests as they improve data collection, enable efficient resource allocation and enhance the visitor experience through better navigation and information dissemination. The aim of our work was to find out whether people visiting urban and suburban forests in Warsaw consciously plan their visits to forest areas, what ICT tools they use during and after a forest visit, and whether they share their experiences related to forest recreation on social media after the visit. The research focused on urban and suburban forests in the Warsaw metropolitan area, Poland. Data on visitors’ characteristics, recreation habits and digital skills were collected in an online panel survey in November 2023 (n = 1413). The results showed that respondents most frequently visited forest areas around Warsaw 2–3 times a month and several times a year. The vast majority of respondents planned their visits directly on the day of the trip (34.96 %) and used their own knowledge and experience when planning their trip to the forest. More than half of respondents (69 %) stated that they use various types of digital tools when visiting forest areas, most commonly smartphones with GPS functionality. Most respondents stated that they had advanced (43.38 %) or at least advanced (32.06 %) knowledge of using digital tools. 39.49 % of respondents stated that they do not use the internet to share information about their forest visits. The research results presented in the sentence indicate the complexity of using digital tools in the management of outdoor recreation and tourism. On the one hand, our research clearly shows that digital tools are an integral part of modern outdoor recreation and tourism management and provide valuable insights, on the other hand, most respondents planned their visits directly on the day of departure, relying mainly on their own knowledge and experience, rather than on digital tools. This knowledge can be used to develop forest management strategies, environmental education, monitoring tourist flows and promoting responsible recreation worldwide. Further research is needed to analyse the use of digital tools in digital forest recreation.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100697"},"PeriodicalIF":2.7,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methodology for selecting potential CO2 sinks in Macaronesia: The case of Gran Canaria","authors":"Seun Oladipo ,&nbsp;Lorenzo C. Quesada-Ruiz ,&nbsp;Jose A. Caparros-Santiago","doi":"10.1016/j.tfp.2024.100698","DOIUrl":"10.1016/j.tfp.2024.100698","url":null,"abstract":"<div><div>Carbon dioxide (CO₂) accounts for 80% of the greenhouse gas emissions in the atmosphere. One of the several ways to mitigate CO₂ emissions is through afforestation, which prevents catastrophic environmental consequences. The mean average emission per tourist in the Canary Islands on their way to the islands is 0.48 Tn. Like most urban cities, the island of Gran Canaria faces the problem of CO₂ emissions due to anthropogenic and human activities. Vegetation coverage significantly influences the distribution of temperature. The correlation between Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) of Gran Canaria, using satellite images from Landsat 8 and Sentinel-2, revealed a strong inverse relationship within all land use types, with an R2 value of 0.39. Land suitability analysis is a prerequisite for optimum utilization of available land resources. This study developed a suitability map for afforestation based on land use land cover, topographic, meteorologic, and socio-economic factors. Eight factors, including distance from settlements, land use, distance from the road, distance from water, elevation, slope, precipitation, and temperature, were employed according to previous studies, expert consultation, and land suitability mapping experience. After the criteria decision and data acquisition, maps of each criterion were created and transformed using the Suitability Modeler of ArcGIS Pro. The current study results show that 87% of the total area is suitable for afforestation and reforestation projects in Gran Canaria. Instead of using reactive methods to lessen the effects, the study recommends a proactive approach to climate adaptation through nature-based solutions. The study is part of an umbrella project of the Canary Islands and Spain in general, which considers the contributions of local and institutional stakeholders at different stages of the project. The next stage will be to design a forest afforestation and reforestation project, considering the kind of tree species needed, the methods required to implement it, and the management guidelines about the initial years of installation and growth of the new trees. The most crucial technical choice is which forest species to choose, as it will determine the success of the reforestation effort. The new revegetated space's ability to sequester carbon dioxide will primarily rely on the productivity of the land used for forest reforestation, the species chosen, and the introduced planting density.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100698"},"PeriodicalIF":2.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Agroforestry stand age influence physical and chemical soil parameters","authors":"Benjamin Mutuku Kinyili ,&nbsp;Ezekiel Ndunda ,&nbsp;Esther Kitur","doi":"10.1016/j.tfp.2024.100694","DOIUrl":"10.1016/j.tfp.2024.100694","url":null,"abstract":"<div><div>The role of agroforestry in improving soil parameters is well known. However, there is debate as to how age of agroforestry practice affects physical and chemical parameters especially in the tropical region of Sub-Saharan Africa where adoption of the practice is fairly recent. To understand those effects, a study was conducted using soil samples taken in farms adopting/non adopting agroforestry practises, selected using a stratified, random sampling strategy. Soil was sampled from adopters and non-adopters using soil auger. At least five sub-samples were collected from each location and the soil mixed to get an integrated soil sample for analysis. The physical (sand, clay, silt and bulk density), chemical properties (pH, total nitrogen [TN], total phosphorus [TP], total organic carbon [TOC], carbon nitrogen ratio [C/N] and carbon to phosphorus ratio [C/P]) were analyzed in the soil. The exchangeable bases (K, Ca, Mg and Na) as well as micronutrients (Mn, Cu, Fe and Zn) were also analyzed. The results indicated that sand was significantly (<em>P</em> &lt; 0.05) higher among non-adopters compared to adopters while silt and bulk density was significantly (<em>P</em> &lt; 0.05) higher among the adopters compared to the non-adopters. Sand levels decreased while silt and bulk density significantly increased with increasing agroforestry stand age. The TN, TOC and C/P ratio were significantly (<em>P</em> &lt; 0.05) higher among adopters and increased consistently with age of adoption, while C/N was higher among non-adopters and decreased with increasing age of agroforestry stand. The trend in exchangeable bases and micro-nutrients in the soil were similar, where higher concentrations occurred among adopters and displayed an increase with regard to age of agroforestry stand. Our results support the hypothesis that age of agroforestry practice affects soil in parameter-specific patterns.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100694"},"PeriodicalIF":2.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Historical forest use constrains tree growth responses to drought: A case study on tapped maritime pine (Pinus pinaster)","authors":"Cristopher Fernández-Blas ,&nbsp;Paloma Ruiz-Benito ,&nbsp;Antonio Gazol ,&nbsp;Elena Granda ,&nbsp;Eva Samblás ,&nbsp;Irene Granado-Díaz ,&nbsp;Miguel A. Zavala ,&nbsp;Cristina Valeriano ,&nbsp;J.Julio Camarero","doi":"10.1016/j.tfp.2024.100699","DOIUrl":"10.1016/j.tfp.2024.100699","url":null,"abstract":"<div><div>Resin extraction from <em>Pinus pinaster</em> (maritime pine) trees was an important economic activity for most of the 20th century in Mediterranean forests, until the decrease in resin prices that led to their abandonment in the 1960s-1970s. Reduced tree growth is often observed after long periods of resin tapping, but it is unknown how these formerly tapped stands respond to recent climate warming and aridification. We sampled three historically tapped maritime pine stands in Teruel, eastern Spain, to understand differential growth and responses to climate in resin tapped and non-tapped trees. Using dendrochronological methods, we compared tree growth trends and responses to climate in tapped and non-tapped trees. Overall, tree growth was higher in resin tapped trees than in non-tapped trees, which were generally younger. However, tree growth decreased over time, increasing the negative effects of late spring temperatures, summer drought and reduced summer precipitation, with increased sensitivity to drought in tapped than non-tapped trees. Among tapped trees, those with larger wound area grew more than those less tapped, and were more sensitive to drought, particularly after the 80 s. Our results suggest that the legacy effects of previous management can constrain tree responses to climate change by increasing the sensitivity of tree growth to drought.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100699"},"PeriodicalIF":2.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing afforestation and reforestation strategies to enhance ecosystem services in critically degraded regions","authors":"Fahrudin ,&nbsp;Anjar Dimara Sakti ,&nbsp;Hazel Yordan Komara ,&nbsp;Elham Sumarga ,&nbsp;Achmad Choiruddin ,&nbsp;Vempi Satriya Adi Hendrawan ,&nbsp;Therissia Hati ,&nbsp;Zuzy Anna ,&nbsp;Ketut Wikantika","doi":"10.1016/j.tfp.2024.100700","DOIUrl":"10.1016/j.tfp.2024.100700","url":null,"abstract":"<div><div>Human activity has caused massive forest ecosystem damage, threatening the global environmental balance. Afforestation and reforestation are crucial strategies for the restoration of forest ecosystem functions. This study was conducted on Belitung Island, Indonesia, which has experienced forest degradation due to mining activity and is currently undergoing forest restoration efforts. This study aimed to identify priority areas for afforestation and reforestation using an innovative approach that integrates multi-criteria analysis (MCA) and machine-learning techniques based on ecosystem service (ES) indicators, wildfire susceptibility, and environmental pressure. This study is the first to combine long-term remote sensing data with machine learning to develop priority scenarios for afforestation and reforestation. Results show that low-priority afforestation areas cover 24,479.66 ha (20.45 %), medium-priority areas 58,703.30 ha (49.04 %), and high-priority areas 36,521.98 ha (30.51 %). For reforestation, low-priority areas cover 23,123.45 ha (30.45 %), medium-priority areas 38,197.36 ha (50.3 %), and high-priority areas 14,618.27 ha (19.25 %). This study is expected to serve as a reference for sustainable forest ecosystem restoration efforts in various regions by leveraging ES approaches and environmental conditions using remote-sensing technology.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100700"},"PeriodicalIF":2.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges for community-owned forests between traditional and new uses of forests: A Q-methodology study applied to an alpine case","authors":"Giacomo Pagot,&nbsp;Paola Gatto","doi":"10.1016/j.tfp.2024.100688","DOIUrl":"10.1016/j.tfp.2024.100688","url":null,"abstract":"<div><div>There is a worldwide increasing interest in forest ecosystem services (FESs), especially regulating and cultural ones. Providing FESs requires the shift towards a multifunctional forest management approach, and forest owners are key figures in this process. Current research on motivations and attitudes of forest owners towards provision of regulating and cultural FES focuses on non-industrial private forest owners but neglects community-owned forests, despite them being often innovative and multifunctional models of forest resource management. The paper explores the views of community-owned forest institutions to provide forest recreation. Sixteen cases have been studied in an alpine valley in Italy, where these institutions have been existing since hundreds of years. Q methodology was used. Q methodology is a semi-qualitative technique used to systematically analyze diverse points of view among individuals or groups by having them rank statements on a topic, allowing for the identification of similar views. Results show a general positive view of community-owned forest institutions towards providing recreation but with nuanced positions, which could be clustered in two groups. The first and largest group looked favourably at providing more forest recreation; the change towards forest recreation was however conditional to maintain adequate levels of income and receiving external support from public authorities. The latter and smaller group was more sceptical, being concerned about the potential negative impacts of visitors in the forest. Both groups stressed that sensitivity and respect of the visitors towards the property are decisive factors for accepting and improving public accessibility. The paper reflects on the challenges for these traditional forms of forest ownership in front of new societal demands, and concludes that, regarding forest recreation, the attitudes of community-owned forest institutions are not very different than those of other private forest owners.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100688"},"PeriodicalIF":2.7,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of phosphite treatment on Phytophthora community assemblages and inoculum abundances in Phytophthora-infected forest soil","authors":"Shannon Hunter ,&nbsp;Nick Waipara ,&nbsp;Bruce Burns ,&nbsp;Peter Scott ,&nbsp;Nari Williams","doi":"10.1016/j.tfp.2024.100687","DOIUrl":"10.1016/j.tfp.2024.100687","url":null,"abstract":"<div><div><em>Phytophthora</em> are causing declines in forest tree species worldwide and the chemical control treatment, phosphite, is the only treatment consistently shown to provide some protection to natural ecosystems from <em>Phytophthora</em> diseases. Phosphite inhibits <em>Phytophthora</em> growth and sporulation whilst boosting defence responses in the plant host. It is unclear, however, the extent of the impact of phosphite on <em>Phytophthora</em> species assemblages and inoculum abundances in soil around trees following treatment within natural ecosystems. In New Zealand, kauri (<em>Agathis australis</em>), an endemic and threatened foundation species, suffers from a dieback disease primarily caused by <em>Phytophthora agathidicida</em>. Phosphite is applied by trunk injection to kauri and has been shown to improve resin ‘bleed’ symptoms from basal trunk lesions and to promote recovery of thinned canopies. <em>Phytophthora</em> community and inoculum abundance were investigated in response to phosphite treatments at two field sites (Huia and Waitoki) in infected kauri stands in Auckland, New Zealand. At Huia, soil sampling and tree health surveying were conducted in November 2023 on trees treated with phosphite in 2012 as part of an earlier study. At Waitoki, the response to phosphite treatment was monitored 6 and 18 months following treatment. <em>Phytophthora</em> species were detected using soil baiting and metabarcoding of Environmental DNA (eDNA) from soil and quantified with qPCR of root and soil DNA. Three species were detected with soil baiting (<em>P. agathidicida, P. cinnamomi,</em> and <em>P. multivora</em>) and two additional species with metabarcoding (<em>P. pseudocryptogea</em>, and an unknown clade 7 species similar to <em>P. europaea</em>). <em>Phytophthora cinnamomi</em> was the most abundant species, followed by <em>P. agathidicida.</em> Both species were more likely to occur together than by chance alone and were associated with declining tree health. The <em>P. europaea</em>-like species was in approximately 50 % of the samples and was less likely to occur in roots with poorer health, or in association with <em>P. agathidicida</em>. The abundance of <em>P. agathidicida</em> inoculum was lower in the soil around the phosphite-treated trees than around the untreated control trees 1.5 years after treatment at Waitoki. Phosphite halted the lateral expansion of basal resin bleeds, and resin viscosity was reduced. Not only did phosphite treatments improve kauri dieback symptoms, but the phosphite treatments potentially had a direct impact on the epidemiology of the disease by reducing inoculum load around treated trees, with direct implications for disease management as an effective way to protect uninfected areas and minimise the spread of inoculum from infested zones.</div></div>","PeriodicalId":36104,"journal":{"name":"Trees, Forests and People","volume":"18 ","pages":"Article 100687"},"PeriodicalIF":2.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}