Forecasting commercial nursery seed and plant availability has been relatively straightforward up to recent times.
Forecasting commercial nursery seed and plant availability has been relatively straightforward up to recent times.
Future afforestation and reforestation programmes are more uncertain as is the tree species mix with a shift from conifers to native broadleaves.
While the range of conifers and naturalised broadleaves is predictable, up to 25 native tree and shrub species are required for a more species-diverse afforestation programme and ACRES scheme.
No single nursery is geared to fulfil species’ programmes of this
variety, which is why Teige Ryan and John Kavanagh of None so Hardy Nurseries approached Coillte and Fermoy Woodland Nurseries to discuss future seed and plant requirements last March.
Arising from their discussions, Derek Felton was commissioned to produce a report, titled Tree Seed 2024: Projected Requirements and Availability.
“This is concerned predominantly with sourcing and quantifying seed of native species in anticipation of increased take-up of the new afforestation grants, post harvesting replanting requirements and the needs of the tree planting aspects of the ACRES environmental farm schemes,” says Felton.
While the forestry sector will be interested in nursery production for afforestation in the report, plant demand to date, under the ACRES scheme, has amounted to around 10 million plants which “has put considerable stress on nurseries to supply stock,” maintains Felton.
Regarding ACRES 2 (2028-2033), Felton says: “Hedgerow planting amounting to 2,500km (12.5 million plants) over the duration of the scheme is anticipated.”
Afforestation
Felton is all too well aware that the 8,000ha planting programme will not be achieved but goes through the plant requirements of the afforestation programme under each Forest Type (FT).
FT 1(Native Forest): To plant 1,150ha, this FT needs 2.8m plants comprising alder (268,800), downy birch (720,000), wild cherry (48,000), pedunculate and sessile oak (720,000), rowan (160,000), hazel (232,800), hawthorn (75,840), grey willow (192,000), Scots pine (288,000), holly (104,640), crab apple (16,800), spindle (4,800) and guelder rose (24,000). To further complicate this FT, customers may also require silver birch, aspen, bird cherry, blackthorn, goat willow, elder, whitebeam, yew, wych elm and arbutus. FT2 (Forests for Water) and FT3 ( Forests on Public Land): Each FT has a target of 150ha requiring 375,000 native plants.FT 4 (NeighbourWood) and FT5 (Emerging Woodland/ Re-wilding): These FTs are unlikely to exceed 50ha each with limited plant requirements, especially FT5, where the emphasis is on natural regeneration.FT 6 (Broadleaf Forest): A target of 250ha is proposed which will require sessile and pedunculate oak (406, 250), beech (31,250), birch (62,500), Scots pine (62,500) and other conifers (62,500).FT 7 (Diverse Broadleaves): The target is to achieve 250ha, comprising alder (187,500), birch (187,500), other broadleaves (62,500) and nurse conifers (187,500).FT 8 (Agroforestry): Unlikely to make significant plant demands as only 100ha forecast and planting density is 400 trees/ha. FT 10 (Continuous Cover Forestry): Based on an 800ha target, Felton estimates a 2.0m plant requirement. He outlines the two scenarios depending on the nature of the existing forest.
“The larger area is dedicated to Sitka spruce forests and the smaller to Norway spruce or western red cedar,” he says. “ Both schemes permit a maximum of 55% of the main conifer species and a minimum of 20% broadleaves. FT 11 (Mixed High Forests): With an annual target of 400ha and 2.0m plants, this FT allows for a wide range of commercial conifer species, but likely to comprise Scots pine (700,000), Douglas fir (700,000), other conifers (200,000), alder (200,000) and birch (200,000). FT 12 (Mixed High Forests with Sitka spruce): While the target is 4,645 ha, it is likely to fall short by up to 80%. Should the target be eventually achieved, Felton estimates a requirement of 7.55m Sitka plants, 1.15m other conifers, 1.16m alder and 1.16 birch.Native Tree Area (NTA) 1 & 2: Up to May this year, 252 approvals were issued from 340 applicants. The NTA will require 277,200 plants. Consultation
The report should focus minds on the complexities and challenges of seed availability and sourcing as well as nursery plant production lead in times.
It should also generate greater consultation between nurseries and the Department especially when new species are introduced that may take years to reach production (see panel).
“The reintroduction of European larch together with the introduction of coast redwood, giant redwood and Japanese cedar will require adequate consultation with the nurseries and an understanding of the lead-in time to produce saleable plants,” says Felton not unreasonably.
Seed collection, plant delivery and supply issuesA crucial aspect of nursery production is the time it takes from seed collection to tree plant delivery to customers. Most tree seed is harvested between September and November before being stratified.
Stratification is a process to help seeds germinate over the winter before they are sown in nursery seed beds the following spring. Later, the seedlings, are transferred to transplant lines before they are lifted and ready for sale.
So, as Derek Felton outlines, seeds harvested in autumn 2024 will be generally ready for sale in the 2026/27 planting season and if stronger plants are needed they can be held in the transplant lines for a further year and delivered in 2027/28.
So the interval between seed collection and plant availability can be up to three and a half years.
All this presupposes that seed will be available which is not always the case. “Overall tree seed production varies greatly from species to species and from year to year,” Felton explains.
“For many species, there are gaps of two to three years between good seed [or mast] crops. In the case of oak, there can be gaps of five or six years between mast crops. Low seed cropping in intermediate years is often concurrent with high proportions of empty or unviable seed. Continuity of native seed supply is a major issue for nurseries.
“Unlike the main commercial conifer species, seeds of native broadleaves are collected on an annual basis with quotas to meet anticipated requirements,” says Felton.
“Only small quantities are stored at present. It would be of considerable value if native species with orthodox storage capacities be over-collected in times of plenty and stored until required. Ideally, two to three years seed supply would be held in reserve.”
The report recommends further registration of oak stands, and increasing the number of seed collectors and stand inspections. Felon is not impressed with the performance of existing seed orchards in providing “worthwhile acorn production."
He does however see merit in converting the oak breeding orchard in Ballyhea to a provenance-tested seed orchard.
Trinity College Dublin survey on farmers’ attitudes to forestryTrinity College Dublin is carrying out a survey to help “understand the challenges farmers face with afforestation and to explore potential financial incentives that could encourage greater participation,” said Laqiqige Zhu, one of the research team.
Laqiqige Zhu, member of the Trinity College Dublin farm survey research team.
“Farmers’ insights are invaluable in shaping policies that truly reflect the needs of their communities,” she added.
The survey aims to identify issues such as the low uptake of afforestation and also “to explore potential changes in replanting requirements, premium payment durations, and premium amounts to encourage greater participation in forestry."
This is an important survey and we encourage readers to participate by clicking here.
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