Social Licence to Operate (SLO) is an increasingly strategic concern in forestry, yet its evaluation remains largely qualitative. This study presents the first quantitative framework for assessing SLO in New Zealand's forestry sector, adapted from the Boutilier and Thomson model, originally developed for the mining sector. The framework integrates trust constructs with sector-specific indicators aligned to the triple-bottom-line-social, environmental and well-being dimensions. A survey across nine wood supply regions revealed significant regional variation, with institutional trust (2.60) and environmental approval (2.75) scoring lowest. The overall SLO score of 2.9 reflects an 'acceptance' level. Reliability was confirmed (Cronbach's alpha > 0.84). These findings highlight the need for improved transparency, community engagement and ecological stewardship. The framework enables systematic monitoring and strategic response to stakeholder expectations. By quantifying SLO and linking it to sustainability metrics, this research advances evidence-based governance and supports sustainable production in New Zealand's forestry sector.

Although soil respiration is known to increase with warming, the long-term stability of total forest soil organic carbon (SOC) stocks and their compositional changes remain uncertain. Through a 12-year soil warming experiment (+1.21°C) in temperate and subtropical forests, we found that SOC content remained stable in both 0-10 cm and 10-20 cm layers. A supporting global meta-analysis further indicated that substantial SOC loss in forests occurs only under sustained warming exceeding 2°C. However, after 12 years, warming induced distinct compositional shifts. In the temperate forest, mineral-associated C and the aromatic C/O-alkyl C ratio declined, suggesting weakened mineral protection and lignin decomposition. Conversely, in the subtropical forest, alkyl C and the alkyl C/O-alkyl C ratio increased, indicating accumulation of recalcitrant compounds. These results demonstrate that while mild long-term warming below 2°C can maintain overall SOC stocks, it drives ecosystem-specific compositional transformations that may influence future soil C persistence under continued climate change.

Abstract Landowners' conceptualisation of the connection between trees and water matters for their land‐use decisions and the allocation of water resources in general. Tree–water interactions are commonly explored and explained through a biophysical lens where competing demands for water from other land uses, such as plantation forests and horticulture, are important. However, other values (positive or negative) can also play a role. Using a mixed method approach, we explored the key stakeholders' and landowners' perceptions of trees on farms and their interactions with water resources in three regions of New Zealand. Of the 363 surveyed participants, a large majority (70%) reported the presence of (exotic and native) trees on their farms. Landowners, composed of farmers and lifestyle block owners, were identified as direct actors influencing the landscape's socio‐hydrology, and most of them rely on natural water supplies for their farms. Our research reveals that issues relating to trees and their interaction with water—including climate change‐induced droughts, the effects of forest management and harvesting practices on water, and the decline in water quality—were raised by key stakeholders. Landowners chose to keep trees on their farms to enhance biodiversity, mitigate soil erosion and provide shelterbelts. They also value trees for shade for their livestock and for improving water quality. Our findings suggest that older landowners, those who perceive water quality as less concern and those who perceive lower flood risks are less likely to plant trees. This study sets the foundation for understanding the relationship between trees and water in New Zealand. However, additional research is necessary to assess the synergies and trade‐offs arising from the interactions of socio‐hydrological systems. Read the free Plain Language Summary for this article on the Journal blog.

Climate change poses a significant challenge for forest growers. However, understanding climate change adaptation including the behaviour and decisions of forest growers remains unexplored in New Zealand, despite the forestry sector being a significant export leader and major contributor to regional economies. To explore this, we conducted surveys of 60 forest growers from organisations which collectively manage more than 70% of New Zealand's plantation forests. The results showed that 47% of the respondents perceived that climate change will affect their forest growing, and 60% perceived that climate change will increase wildfire frequency and pest and disease outbreaks. Only 21% of the respondents reported that they had taken adaptation measures directly. Lack of resources and motivation were among the barriers that respondents identified. A logistic regression analysis revealed that climate change perception, research to improve forest growers' adaptive capacity, climate change information, forest grower age and forestry experience are significantly associated with actual adaptation decisions. Risk perceptions central to protection motivation theory (e.g. vulnerability, probability and severity) were not linked to actual adaptation decisions, suggesting that widening adaptation analyses beyond individual perceptions as predictors of climate change adaptation may provide insights for fit-for-purpose climate change adaptation policies for the sector.

The assumption that climatic growing requirements of invasive species are conserved between their native and non-native environment is a key ecological issue in the evaluation of invasion risk. We conducted a growth chamber experiment to compare the effect of water regime and temperature on the growth and mortality of native and invasive populations of common gorse seedlings (Ulex europaeus L.). Seeds were sampled from 20 populations of five areas from both native (continental France and Spain) and non-native areas (New Zealand, Canary and Reunion islands). The seedlings were grown over 36 days in two temperature treatments (ambient and elevated) combined with two water treatments (irrigated or droughted). The elevated temperature (ET) was defined as the highest temperature observed at the niche margin in the different countries. While ET increased seedlings growth, the drought treatment increased mortality rate and limited seedlings growth. Under ET and drought, native populations showed a greater mortality rate (53%) than invasive populations (16%). Invasive seedlings also showed higher above- and belowground development than native ones under these constrained climatic conditions. While phenotypic plasticity did not differ between native and invasive populations, the difference between populations in terms of total dry mass could be related to differences in the climate of origin (precipitation in particular). Assessing the importance of phenotypic changes between populations within invasive species is crucial to identify the margins of their climatic distribution range and to highlight areas where management efforts should be concentrated in order to limit its spread.

Climate change is likely to have significant impacts on the forestry sector in New Zealand. However, an understanding of how forest growers are reducing their risks from climate change impacts is still in its infancy. This paper applies the protection motivation theory to identify socio-psychological factors influencing forest growers’ adaptation to climate change. This study presents the survey results from 60 forest growers who have the combined responsibility for managing more than 70% of New Zealand’s plantation forests. We investigated whether their perceived response efficacy, self-efficacy and their understanding of response costs are predictors of their protective or adaptive measures. Based on our survey, risk reduction and risk spreading are the two types of protective measure frequently reported by the respondents to deal with climate risks. Consistent with the protection motivation theory, our findings show that respondents who are more likely to implement protective or adaptive measures if they perceive the threat severity to be high have high self-efficacy and resource efficacy, and exhibit low maladaptive responses such as evading and postponing behaviours. Furthermore, our findings also suggest that there is a low self-efficacy belief with strong maladaptive behaviour among the respondents that negatively influence their motivation to implement adaptation measures. This result provides guidance to policy makers, researchers and forest companies on how to make climate change adaptation efforts effective by considering the forest growers motivation to adapt to climate change.

Context Biuret has potential to improve tree growth when applied at high rates as a slow-release nitrogen (N) fertiliser. However, there is little comparative research into the transformation of biuret and urea-N in forest soils. Aims This study comparatively investigated the mineralisation, nitrification and immobilisation of biuret and urea-N in two forest soils (a sandy loam soil and a silt loam soil) to further evaluate the suitability of biuret as a slow-release N source. Methods A 112-day long soil C and N mineralisation incubation study was conducted following application of 0, 4.08, 40.8 and 408 mg N kg−1 soil of biuret (referred to as control, B4, B41 and B408) and urea (referred to as control, U4, U41 and U408). CO2-C, microbial biomass C and N, NH4+-N and NO3−-N were measured at six times (on Days 2, 7, 14, 28, 56 and 112) to quantify net mineralisation and nitrification. Key results In both soils, biuret (especially in B408) was slowly mineralised with a steady increase in soil NH4+-N while urea was readily hydrolysed with a sharp increase and subsequently considerable decrease in soil NH4+-N. B408 had less nitrification than U408 in both soils, especially during the first 56 days. Conclusions Due to the lower mineralisation, nitrification and greater immobilisation, more biuret-N remained in the soils compared to urea-N. Biuret could be used as a potential slow-release N fertiliser in forest soils. Implications The research findings could have important implications for future biuret fertiliser development for plantation forests.

To provide the forest industry with a better understanding of alternatives to simulate future adaptation pathways under evolving climatic and socio-economic uncertainty, we review the literature on how adaptation decisions are modelled in the context of plantation forests. This review leads to the conclusion that the representation of adaptation behaviour and decision-making remain very limited in most of the agent-based models in the forestry sector. Moreover, theoretical frameworks used to understand the adaptation behaviour of forest owners are also lacking. In this paper, we propose the application of protection motivation theory (PMT) as a framework to understand the motivation of forest owners to reduce the negative impacts of climate change on their forest plantations. Furthermore, the use of PMT allows factors affecting the maladaptive behaviour of forest owners to be examined. A survey of New Zealand foresters showed that less than 10% of smallholder forest owners adopted adaptation strategies. This result highlights the importance of addressing the research question “what motivates forest owners to take risk reduction measures?” Exploring this question is crucial to the future success of the New Zealand forestry sector and we suggest that it can be addressed by using PMT. This paper proposes a conceptual framework for an agent-based model as an alternative to simulating adaptation pathways for forest plantations in New Zealand.

The biodiversity in soil ecosystems is simultaneously incredibly rich and poorly described.In countries such as New Zealand, where high endemism in plant species emerged following extended geographical isolation, it is likely similar evolutionary pressures extended to soil microbial communities (our biodiversity 'dark matter').However, we have little understanding of the extent of microbial life in New Zealand soils, let alone estimates of endemism, rates of species loss or gain, or implications for systems where plants and their microbiomes have co-evolved.In this study, we tested for the impacts of land-cover type (native forest, planted forest with exotic conifers, and pastoral agriculture) on soil bacterial communities and their functional potential, using environmental microarrays (PhyloChip and GeoChip, respectively).This evaluation was conducted across four environmentally different locations (Hokitika, Banks Peninsula, Craigieburn, and Eyrewell).The environment from which samples were collected was the largest and most significant factor associated with variation in bacterial community assemblage and function.As such, novel pockets of bacterial biodiversity, with discrete ecosystem function, may be present in New Zealand.There was some evidence to suggest that change in land cover affected soil bacterial species, but not their functions.Secondary testing found this effect was restricted to differences between native forest and agricultural land use.Bacterial communities and functions between native and planted forests were similar.Analysis of soil environmental properties among samples found that land cover effects were underpinned by changes in soil pH that typically accompanies application of lime in agricultural systems, but is uncommon in planted forests.When compared with other studies conducted in New Zealand, we conclude that: (1) different locations can harbour distinct communities of soil microbial diversity, and (2) land-use intensification, not land cover change per se, shifts microbial biodiversity through alteration of primary habitat conditions, particularly soil pH.

It is established that the long-term productivity of planted forests now and into the future requires a consistent supply of nutrients from soil for sustained growth over multiple rotations, and the importance of soil function to other important planted forest ecosystem services such carbon cycling is now increasingly recognised. In addition, advances in analytical techniques have provided capability to investigate the soil biological communities that supports these functions. The New Zealand Long-Term Site Productivity (LTSP) trial series has been a fundamental research infrastructural asset for exploring the impacts of harvest residue and forest floor removal, providing new insights into the sustainability of soil nutrient and organic matter (soil carbon) stocks and the diverse range of soil biological activity that supports many ecosystem level processes essential to continuous forest productivity. This paper provides a globally unique synthesis from a long-term test of a universal hypothesis and discusses how the findings throughout the similar to 30 year lifespan of the trial series have supported the development of knowledge and tools that are leading to changes to forest management practice. Key examples include the development of the Nutrient Balance Model (NuBalM) platform, demonstration of the critical importance of harvest residues and forest floor material at low fertility sites, and new evidence identifying the enduring sensitivity of the soil microbial community to disruption caused by harvesting intensity. Combined, these results have underpinned significant changes in how planted forest soils in New Zealand are managed, in terms of both nutrition and the influence of beneficial soil microbes. Discussion of these outcomes is particularly timely given the increasing global demands on wood and fibre supply, and demonstrates the importance of long-term site productivity trials to the ongoing ability of forest growers and managers to deliver multiple benefits from planted forests. An outlook is provided on what the future might hold in terms of increasing intensification and the implications of multiple rotations over a larger area of forest in the future.

Forest harvesting practices remove tree biomass and the nutrients that they contain. There is uncertainty around the impact of this nutrient removal on the long-term sustainable production of forests over multiple rotations. To explore the impact of harvest management practices on planted forest sustainability, three long-term trials in Pinus radiata D. Don forests were assessed at the end of their second rotation of 26 to 27 years to determine the impact of harvest residue removal and fertiliser additions on sustainable forest productivity. The harvest residue removal treatments were stem only (SO), whole-tree (WT), and whole-tree plus forest floor (FF) removal with and without urea-nitrogen fertiliser additions (cumulative range across three sites 950 - 3200 kg N ha-1) from early rotation out to mid-rotation (last fertiliser application age range across sites 8 - 22 years). The FF removal treatment reduced soil carbon and nitrogen stocks throughout the subsequent rotation, whereas forest floor carbon and nutrient stocks had recovered from the FF removal treatment by the end of the rotation. Forest productivity was reduced at one site with the FF removal treatment, taking 3 years longer for stems to reach 35 cm diameter at breast height than other residue removal treatments. Between WT and SO harvest residue treatments there were very limited impacts on soil carbon and nutrient stocks, no impact on forest floor mass, carbon and nutrient stocks and the sum of the above ground live biomass, carbon and nutrient stocks or tree productivity. Across all harvest removal treatments fertiliser addition increased soil carbon and nitrogen stocks for sites with low initial soil stocks. The increased soil carbon and nitrogen stocks from fertiliser addition were associated with forest productivity gains with the time to reach 35 cm (diameter at breast height) for one site reduced by 3 - 5 years. Fertiliser addition to sites with FF removal was able to mitigate soil carbon and nitrogen stocks only when very large amounts of fertiliser were added (cumulative amounts of 1150 and 3200 kg N ha-1). The end of rotation results from this long-term study demonstrate the importance of harvest residues and forest floor material at low fertility sites for long-term nutrient sustainability in planted forests.

Drought events are predicted to occur more frequently, but comprehensive knowledge of their effects on methane (CH4) oxidation by soil methanotrophs in upland ecosystems remains elusive. Here, we put forward a new conceptual model in which drought influences soil CH4 oxidation through a direct pathway (i.e., positive effects of soil CH4 oxidation via increasing soil aeration) and through an indirect pathway (i.e., negative effects of in planta ethylene (C2H4) production on soil CH4 oxidation). Through measuring soil CH4 efflux along a gradient of drought stress, we found that drought increases soil CH4 oxidation, as the former outweighs the latter on soil CH4 oxidation, based on a mesocosm experiment employing distinct levels of watering and a long-term drought field trial created by rainfall exclusion in a subtropical evergreen forest. Moreover, we used aminoethoxyvinylglycine (AVG), a C2H4 biosynthesis inhibitor, to reduce in planta C2H4 production under drought, and found that reducing in planta C2H4 production increased soil CH4 oxidation under drought. To confirm these findings, we found that inoculation of plant growth-promoting rhizobacteria containing the 1-aminocyclopropane-1-carboxylate deaminase alleviated the negative effects of drought-induced in planta C2H4, thus increasing soil CH4 oxidation rates. All these results provide strong evidence for the hypothesis that in planta C2H4 production inhibits soil CH4 oxidation under drought. To our knowledge, this is the first study to manipulate the negative feedback between C2H4 production and CH4 oxidation under drought stress. Given the current widespread extent of arid and semiarid regions in the world, combined with the projected increased frequency of drought stress in future climate scenarios, we provide a reliable means for increasing soil CH4 oxidation in the context of global warming.

Stem growth reflects genetic and phenotypic differences within a tree species. The plant hydraulic system regulates the carbon economy, and therefore variations in growth and wood density. A whole-organism perspective, by partitioning the hydraulic system, is crucial for understanding the physical and physiological processes that coordinately mediate plant growth. The aim of this study was to determine whether the relationships and trade-offs between (i) hydraulic traits and their relative contribution to the whole-plant hydraulic system, (ii) plant water transport, (iii) CO2 assimilation, (iv) plant growth, and (v) wood density are revealed at the interclonal level within a variable population of 10 Pinus radiata (D. Don) clones for these characters. We demonstrated a strong coordination between several plant organs regarding their hydraulic efficiency. Hydraulic efficiency, gas exchange, and plant growth were intimately linked. Small reductions in stem wood density were related to a large increase in sapwood hydraulic efficiency, and thus to plant growth. However, stem growth rate was negatively related to wood density. We discuss insights explaining the relationships and trade-offs of the plant traits examined in this study. These insights provide a better understanding of the existing coordination, likely to be dependent on genetics, between the biophysical structure of wood, plant growth, hydraulic partitioning, and physiological plant functions in P. radiata.

The Tibetan alpine meadow ecosystem is an important part of the Eurasian grasslands and is experiencing intense warming at approximately three times the global warming rate and rapid degradation. However, little is known about the effect of warming and degradation and their interactions on ecosystem functions like soil carbon (C) and nitrogen (N) pools and methane (CH4) uptake in this region. Here, we selected a long-term simulated warming site in a Tibetan alpine meadow with different degradation levels. After 4 years of warming, we analyzed soil total C (TC) and total N (TN) contents, extractable organic C (EOC) and extractable organic N (EON) contents as well as methanotrophic activity, abundance and community structure. Soil EOC and EON contents were measured through hot water extraction, whereas methanotrophic activity was measured along a gradient of CH4 concentrations in laboratory incubations. Michaelis-Menten kinetics analysis [maximal rate of velocity (V-max) and half-saturation constant (K-m)] was used to quantify changes in methanotrophic activity among the treatments. Active methanotrophic communities in the natural soils were measured via DNA-based stable isotope probing (SIP). The results showed that warming significantly increased soil EON contents, whereas degradation significantly decreased soil TC and TN contents, and EOC and EON contents. Methanotrophic activity was significantly lower at different levels of degradation but no significant effects were observed under warming. Changes in soil methanotrophic abundance among the treatments followed the same trend, but warming and degradation had no interactive effects on methanotrophic activity and abundance. Active methanotrophic communities in the natural meadow soils were dominated by Merhylosinus (a Type II methanotroph). In conclusion, our results indicate that soil C and N pools and CH4 oxidation capability were influenced more strongly by degradation than warming. However, warming may have an additional effect on the stability of these important ecosystem processes, regardless of degradation in this region.

Global interest in addressing knowledge gaps relating to the effect of forest harvest intensity on soil fertility and long-term site productivity has resulted in the installation of numerous experiments, including Long-Term Site Productivity (LTSP) trials. To explore this issue in the context of the New Zealand planted forest estate, six LTSP sites were established from 1985 to 1994 across differing climate and soil conditions, then subjected to varying levels of organic matter removal during the harvest of the trees. Here we present data describing live above ground, forest floor and mineral soil carbon and nutrient pools immediately prior to, and following, harvesting at each site. Harvest residue management practices employed included the removal of stem only, whole tree, whole tree plus forest floor, whole tree plus forest floor and topsoil, and the addition of double harvest slash material. The data provides an understanding of biomass, carbon and nutrient pools at harvest and the impact of different harvest removal treatments on these pools. With the maturation of the trees at the LTSP sites, the data acquires even greater future value by enabling changes in soil properties to be quantified and correlated to variations in the biological properties at the site, including site productivity and critical microbial parameters. Overall, these data sets comprise a foundation for New Zealand to address the question - can the productivity of intensively managed planted Pinus radiata be maintained or enhanced through the judicious management of organic matter and nutrient pools over successive growing and harvesting cycles?

It is assumed that greater plant productivity enhances autotrophic respiration (Ra). In a glasshouse trial using a one year old Pinus radiata D. Don clone selected for rapid growth, we examined the relationship between soil respiration, its components and tree growth rates over approximately five months. Soil respiration and Ra were significantly influenced by temperature; the response of heterotrophic respiration (Rh) approached significance. Soil moisture content had no effect on respiration. The productivity of individual clones, measured as volume increment, was not consistently positively correlated with soil respiration across the measurement intervals. Indeed, over the life of the trial it was found that individual tree volume increments were significantly negatively correlated with soil respiration. These results indicate that the most productive trees were associated with lower rates of autotrophic respiration, contradicting past studies. Further work is recommended to determine if this relationship holds true for these, and other, P. radiata clones in forest settings.

Productivity of forest ecosystems is constrained by site resource availability and utilisation at an individual tree level. A better understanding of nitrogen (N) nutrition addition to forest ecosystems is critical for maintaining optimal plantation productivity, given the influence of an environment gradient, genetics, and their interactions. We studied the aboveground growth response in a plantation setting of ten commercial P. radiata genotypes to N-fertilisation using three different N sources, and also assessed the effect of on-site environmental factors on this response. We compared, on equimolar basis, the effect of N-fertilisation with inorganic N (NH4NO3), organic N (L-arginine), and the two N sources combined (L-arginine:NO3−) to that of unfertilised trees on tree height, diameter, descriptors of microsite variability, and climate and seasonal information. After 2.5 years of fertilisation, genotype-specific variation in aboveground growth response to N sources were measured, and these were significantly influenced by field-scale heterogeneity. Across P. radiata genotypes, trees treated with inorganic N forms showed suppressed growth compared to unfertilised trees, while trees fertilised with organic N (either alone or in combination with inorganic N) were not significantly different than the untreated controls. We provide evidence of significant interactions between N source and genotype, N source and cover as well as genotype and microsite variability affecting temporal trends in tree volume. We conclude that the comprehension of field-scale variability in soil properties and associated environmental variables is essential for understanding genotype performance as they are crucial determinants of intraspecific variation in response to N-fertilisation.

Stomatal regulation is crucial for forest species performance and survival on drought-prone sites. We investigated the regulation of root and shoot hydraulics in three Pinus radiata clones exposed to drought stress and its coordination with stomatal conductance (gs ) and leaf water potential (Ψleaf ). All clones experienced a substantial decrease in root-specific root hydraulic conductance (Kroot-r ) in response to the water stress, but leaf-specific shoot hydraulic conductance (Kshoot-l ) did not change in any of the clones. The reduction in Kroot-r caused a decrease in leaf-specific whole-plant hydraulic conductance (Kplant-l ). Among clones, the larger the decrease in Kplant-l , the more stomata closed in response to drought. Rewatering resulted in a quick recovery of Kroot-r and gs . Our results demonstrated that the reduction in Kplant-l , attributed to a down regulation of aquaporin activity in roots, was linked to the isohydric stomatal behaviour, resulting in a nearly constant Ψleaf as water stress started. We concluded that higher Kplant-l is associated with water stress resistance by sustaining a less negative Ψleaf and delaying stomatal closure.

Phenotyping is the accurate and precise physical description of organisms. Accurate and quantitative phenotyping underpins the delivery of benefits from genetic improvement programs in agriculture. In forest trees, phenotyping at an equivalent precision has been impossible because trees and forests are large, long-lived, and highly variable. These facts have restricted the delivery of genetic gains in forestry compared to other agricultural sectors. We describe a landscape-scale phenotyping platform that integrates remote sensing, spatial information systems, and genomics to facilitate the delivery of greater gains enabling forestry to catch up with other sectors. Combining remote sensing at a range of spatial and temporal scales with genomics will ultimately impact on tree breeding globally.