New Zealand supports rich temperate forests believed to have occupied up to 80% of its land area below climatic tree line prior to human arrival in the 11th century, but deforestation, particularly motivated by conversion to agricultural systems in the last 150 years, has decreased today’s forest cover to less than 30% of the original estimate. There is currently interest in relatively large-scale afforestation of degraded lands, and this has initiated research and development to improve seeding of native forest species. We provide a synthesis of available literature, ongoing research, and practical experience to identify critical aspects of candidate afforestation sites, summarize practices and techniques used in current seeding research and operations, and recognize factors that affect success or failure of seeding native species. The main challenges are that pastoral farming has dramatically altered the soil microbiome, non-native mammalian herbivores and weeds reduce seedling establishment success, and many native trees are mast seeding or have recalcitrant seeds. Selection of sites with predictably adequate rainfall, deployment of fast germinating pioneer species, procurement of high-quality seed, availability of appropriate soil symbionts, and post-establishment weed and animal control are all important components of success when seeding native forest species in New Zealand.

Tropical montane cloud forests in Mexico, though rich in unique species, cover less than 1% of the country and face severe deforestation and ongoing threats, especially to oaks (Quercus spp.). Our study in the montane cloud forests in the Jamapa and La Antigua River basins of central Veracruz tested acorn seeding for forest restoration. Field trials were conducted across peri-urban and rural secondary forests, employing a range of acorn protection devices (e.g., wire mesh cages, chili pepper (Capsicum spp.) covering) and site preparation techniques to mitigate predation by rodents (Order Rodentia) and other fauna. The study also assessed the influence of microsite selection and pre-germination treatments on seedling emergence. Various rodents were the main obstacle to seeding success, exclusion devices like wire mesh cages greatly improved outcomes. Effectiveness depended on species, site, and year. Chili pepper coverings did not deter birds, and they exposed the acorns to seed predators. Successful restoration requires careful microsite selection; acorns are less preyed upon by rodents in areas with low to moderate vegetative cover. Seeds should be collected from multiple mother trees during peak fall and inspected for viability. When storage is needed, acorns should be stored under controlled conditions to maintain moisture and prevent fungal contamination. Acorn masting leads to variable seed availability modulating seed predation patterns; mast years are optimal for seeding projects. These findings underscore the need for adaptive, site-specific restoration protocols, including rapid pilot trials and monitoring of acorn production cycles.

Mexico is the country with the highest number of species of the genus Quercus, but there has been little research on their propagation in nurseries. Quercus crassifolia is distributed across more than 50% of the national territory; however, no studies have been conducted to document its morphological growth and plant quality in nurseries for reforestation and forest restoration. Some of the key factors in plant production, principally in a technified system, are the selection of containers, substrates, and fertilizer doses. This study therefore evaluated two container sizes, two mixtures of organic substrates, and two doses of controlled-release fertilizer. After nine months of growth in the nursery, morphometric parameters of the plants were recorded, and quality indices were determined based on these values. The results showed that container size, substrate choice, and fertilization dose all influenced the quality of the plant produced. With both fertilizer doses, the 25:25:50 substrate mixture of fresh pine sawdust, composted pine bark, and moss peat produced plants with the highest values of height, diameter, and shoot, root, and total dry biomass. Considering the factors evaluated, the use of 200 mL containers with the aforementioned substrate mixture and the addition of 7 g L^-1 of controlled-release fertilizer will produce plants of Quercus crassifolia suitable quality for use in reforestation.

On January 15, 2025, American Forests and Planscape convened the 2025 Reforestation Summit at the Google.org offices in San Francisco, California, U.S. This collaborative event combined American Forests’ decades-long experience in post-fire reforestation planning and implementation with Planscape’s innovative, community-driven forest restoration planning platform. The objective of the summit was to initiate the development of an integrated reforestation tool(s) to support an end-to-end pipeline approach to post-fire reforestation. The summit brought together more than ninety leading scientists—both in-person and virtually—from across the United States to advance the state of reforestation science and practice (Figure 1). We first provide a brief summary of the 2025 Reforestation Summit, then describe the decision support tools (DSTs) that were discussed at the summit, and lastly discuss the next steps and challenges for building out an integrated reforestation tool(s).

This article is aimed as a basic introduction to conifer somatic embryogenesis for someone with a general interest in applications of this technique and/or who is interested in starting some practical work in the field. We also present data from an example study on individual trees’ ability to initiate somatic embryogenesis in Norway spruce (Picea abies). A total of 158 trees were each tested for ability and relative competence to initiate somatic embryogenesis from the zygotic embryos by observing the initiation frequency for ten zygotic embryos from each individual tree. Furthermore, we conducted a case study by following the process for SE plant formation for a selection of 48 cell lines that were monitored through the SE developmental pathway, with data collected on the success rates at different steps. We then evaluated the relative importance of different steps for the outcome of plant formation and yield.

In the context of variable climate conditions, selecting high-quality Sessile oak (Quercus petraea (Matt.) Liebl.) reproductive material is crucial for sustainable forestry. This research aimed to assess the genetic potential of 86 selected plus trees by analyzing seedling morphological characteristics and quality indices. The ultimate goal was to identify the most promising genotypes for establishing seed orchards. Root collar diameter (D), seedling height (H), stem dry mass (SDM), and root dry mass (RDM) were measured under uniform nursery conditions. The following derived indices were calculated: seedling height to root collar diameter ratio (H/D), stem dry mass to root dry mass ratio (SDM/RDM), and Dickson’s quality index (DQI). Descriptive statistics, one-factorial analysis of variance (ANOVA) and Pearson correlation analysis were performed as well. The results showed significant variability in all observed morphological characteristics and quality indices among half-sib families, confirming a strong genetic influence. Correlation analysis indicated strong positive relationships between DQI and all primary morphological characteristics (r≤0.94), confirming DQI as the most effective integrative indicator of seedling quality. The combined ranking of the half-sib families, based on DQI, H/D, and SDM/RDM, identified those with optimal morphological characteristics, including an optimal H/D ratio, balanced SDM/RDM, and a high DQI value. The identified superior half-sib families represent valuable genetic material for the establishment of future seed orchards, thereby contributing to the production of better-quality seedling material and to improved forest ecosystem resilience under climate change.

The present study was carried out in 16rd year afforestation sampled from southern Turkey of Taurus cedar (Cedrus libani A. Rich) and Crimean juniper (Juniperus excelsa Bieb.). Variation, competition and correlation were examined based on seedling height and stem diameter at base data collected from two samples areas 500 m² each. Growth performances were different at the areas for the species, while averages of Taurus cedar (223.6 for height and 65.3 mm for stem diameter at base) had higher than Crimean juniper (106 cm and 58.5 mm) in total areas. The results emphasized importance of species selection in afforestation. Significant (p<0.05) differences between areas and species were found according to results of analysis of variance. Positive and significant phenotypic correlation (p<0.05, r>0.52) was estimated between the characteristics in both species and areas. It could be used for tending in afforestation areas.

An adult tree of Larix decidua Mill., European larch, was produced from doubling one haploid female gametophyte. Whether this tree can produce normal male meiocytes is the crucial question. This adult’s pollen mother cells (PMCs), or male meiocytes, were squashed and stained. Male meiosis was normal and no abortive pollen grains were observed. This female gametophytic apomict of a conifer, a dihaploid adult, is 100% homozygous yet also reproductively competent with normal male meiosis and functional male pollen. Here we show that doubled female gametophytes can produce embryos and reproductively competent adult trees. This shows a way to gain rapid homozygosity and produce completely inbred lines for larch. This is a novel breeding shortcut reported for the first time for a conifer species.

The production of high-quality planting material for the most commonly used woody species in urban greening is a complex challenge influenced by several factors. One of the key factors in seedling production, especially in pots, is the selection of an appropriate substrate. Testing various substrates for different species is an ongoing process. In Bosnia and Herzegovina, four of the most frequently used taxa for urban planting in the region were tested: two varieties of northern white-cedar (Thuja occidentalis L.), namely 'Smaragd' and 'Columna', as well as European boxwood (Buxus sempervirens L.) and Forsythia (Forsythia × intermedia). One-year-old rooted cuttings were transplanted into two-liter pots using five different substrates: plain soil, compost, lumbrico humus, peat, and a combination of all these substrates. At the end of the growing period, morphometric parameters of the seedlings were measured, and based on these measurements, quality indices were determined. The results showed that each species and variety responded differently to the various substrates. Generally, the best results for most of the taxa were obtained using locally produced lumbrico humus and compost. However, some seedlings, such as Thuja occidentalis 'Smaragd', exhibited similar growth characteristics across all substrates tested. Considering the varying costs of the substrates, it is possible to plan the production of these seedlings with significantly better quality while also reducing production costs.

Sonderegger pine (Pinus x sondereggeri H.H. Chapm.), the natural hybrid of longleaf (Pinus palustris Mill.) and loblolly pine (Pinus taeda L.), commonly occurs in longleaf pine seedlots grown in forest tree seedling nurseries in the southeastern United States. Because longleaf pine seedlings have a grass stage with minimal epicotyl development (< 1 cm), the initiation of stem growth (12 to 15 cm) in longleaf pine seedlots has been used to indicate that hybridization with loblolly pine (Pinus taeda L.) has occurred. Sonderegger pine seedlings are typically culled at the nursery due to observations of poor form and wood quality after outplanting. However, research documenting Sonderegger pine seedling morphology has not been published for more than 60 years, and to our knowledge, no seedling quality assessments have been made. To better understand how morphological traits of longleaf and loblolly pine are expressed in hybrid seedlings, stem length, hypocotyl length, and root collar diameter (RCD) were compared among one-year-old container-grown longleaf, loblolly, and seedlings visually classified as Sonderegger pine. Sonderegger pine seedlings had a range of stem development, with most (62%) seedlings measuring < 12 cm tall. Some pure longleaf pine seedlings had up to 10 cm of stem elongation, but the cause of early height growth in these seedlings is unknown. More than 90% of Sonderegger pine seedlings met or exceeded RCD recommendations for planting loblolly (≥ 3.2 mm) and longleaf pine (≥ 4.75 mm).