Persoonia Pauciflora P.H
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ENVIRONMENTAL IMPACT ASSESSMENT GUIDELINES Persoonia pauciflora P.H. Weston Common name: North Rothbury Persoonia Persoonia pauciflora was previously known as Persoonia sp “North Rothbury”. The following information is provided specimen should also be lodged with to assist authors of Species Impact National Herbarium of NSW, Sydney. Statements, development and activity More detailed mapping of the sub- proponents, and determining and population may be required depending on the nature and scale of the development. consent authorities, who are required to prepare or review assessments of likely Viable but dormant P. pauciflora seeds impacts on threatened species pursuant may be present in the soil seedbank, to the provisions of the Environmental particularly where there are mature Planning and Assessment Act 1979. individuals within 1km. If P. pauciflora These guidelines should be read in individuals occur within 1km, an conjunction with the NPWS investigation into the disturbance history Information Circular No. 2: Threatened (particularly fire history) of the site should Species Assessment under the EP&A be conducted to determine the likelihood of Act: The ‘8 Part Test’ of Significance the existence of a soil seedbank for the species. (November 1996) and with the accompanying “Threatened Species Life cycle of the species Information” sheet. The biology of P. pauciflora is poorly Survey known, however, there is a range of previous and current research into the There are no seasonal survey constraints Persoonia genus from which various for this plant as the mature plant is easily information may be inferred. identifiable during both flowering and non-flowering periods of its lifecycle. P. pauciflora is not likely to reproduce Seedlings, however, may not be easily vegetatively; therefore the plant’s identifiable until they are 0.3-0.5m high. persistence will depend on the production Care should be taken to distinguish and germination of viable seeds that are Persoonia pauciflora from P. isophylla, stored in the seedbank. Persoonia seeds which is a morphologically similar possess a dormancy mechanism that is species. poorly understood (see Wasley 1997). P. pauciflora seeds may germinate as a If suitable habitat is or likely to be consequence of disturbance and/or the present (see attached profile for details), a removal of threats such as grazing and targeted survey for the plant should be frequent slashing. , Persoonias have not conducted. Targeted survey should be generally been successfully grown from conducted over several days (2-3) cuttings or seed, therefore, propagation and depending on the floristics and size of the replanting is not a suitable ameliorative particular site, and should involve both strategy. quadrat and transect sampling strategies. Targeted survey for P. pauciflora should The significance of a particular action not be limited to areas within the existing which physically destroys individual plants distributional limits. Plant heights and will require (i) an examination of the approximate age of individuals should be number of plants to be destroyed in relation inferred from previous fire and other to the proportion of the relevant sub- disturbance histories. If a new sub- population sizes1; (ii) whether the removal population is being surveyed, the of those plants potentially compromises the surveyor should make an accurate long term viability of the remaining sub- population count, map the locations of the plants in a site sketch, and complete 1 Details on the size and locations of sub- an Atlas of NSW Wildlife Flora Record populations are presented in Patrick Card with the NPWS. A voucher (1999). populations (eg opportunities for external proportion of the leaf litter occurring at a recruitment, fragmentation, cumulative site. impact); and (iii) a discussion of whether Habitat modification affects the lifecycle and how the potential seedbank will be of P. pauciflora by altering the ecological affected. That is, whether the seedbank processes within suitable habitat. Habitat will also be destroyed permanently or modification may include: weed invasion, whether seeds are likely to germinate reduced water quality, urban and following disturbance. agricultural runoff, and increased Fire disrupts obligate seeding plant species sedimentation. Since Persoonia species are at the juvenile and adult plant stages of pollinated by a relatively few genera of their lifecycle by killing individual plants native bees, an activity which resulted in and thereby halting the process of seed the loss or inhibited movement of native production and seedbank replenishment. bees within P. pauciflora habitat has the Patrick (1999) notes that P. pauciflora potential to significantly affect the lifecycle appears to be absent from areas where of this plant. there is evidence of recent or severe fires. Threatening processes Several smooth-barked Persoonias are obligate seeders, which do not survive fire, “High frequency fire resulting in the and therefore their persistence relies on disruption of life cycle processes in plants seed germination from the seedbank. A and animals and loss of vegetation minimum fire-free interval is required for structure and composition” is listed in the obligate seeders to mature and produce TSC Act as a key threatening process sufficient viable seed to replace the which may affect P. pauciflora. Other seedbank. The age to reproductive identified threats to P. pauciflora include: maturity in P. pauciflora and therefore a fire, inappropriate hazard reduction specific recommendation in relation to an burning & associated activities (eg trail appropriate fire interval is unknown. construction, turbo-mowing, slashing), Current estimates in one obligate seeding habitat degradation (eg weed invasion & Persoonia (P. mollis ssp maxima) are that reduced water quality), and grazing (see reproductive maturity is not reached until Patrick 1999). approximately eight years following germination, however, peak maturity is not Viable local population likely to be reached until 12-15 years As the size of a viable local population is (NSW NPWS 1999). Caution should be unknown, it should be assumed that a exercised in transferring these estimates to particular sub-population is viable a different species occupying a different regardless of its size, until further habitat, however, a fire free interval of at assessment indicates otherwise. least 10-12 years should be implemented for Persoonia pauciflora until there is Significant area of habitat more detailed information on the lifecycle Given the extremely restricted distribution of the species. of this species, all areas of habitat are In relation to fire management of considered to be significant. Persoonias, Wasley (1997) further notes Isolation/fragmentation the importance of maintaining for long periods of time unburnt “refuge” areas in Three main sub-populations contain 90% Persoonia habitat which act as seed of all P. pauciflora individuals (Patrick sources and facilitate re-invasion of seed 1999), while the remaining 10% occurs as by wallabies and birds. isolated individuals. Management of P. pauciflora habitat should aim to maintain Seedbank disturbance as a result of the continuity of habitat between removal of leaf litter layer of the soil individuals within sub-populations, and profile, may disrupt the lifecycle of P. avoid artificially creating new sub- pauciflora as Persoonia seeds are populations. predominantly stored in the upper layers of the soil profile (Wasley 1997). An Persoonia seeds are vertebrate dispersed example of this kind of disturbance may (eg wallabies, currawongs) thereby include fuel reduction activities such as allowing for relatively large dispersal turbo-mowing, slashing, and the removal distances provided there are opportunities of understorey vegetation. Impacts of this for vertebrate movement (eg vegetation type of disturbance on the P. pauciflora corridors). Fragmentation /isolation of P. seedbank may be minimised by retaining a pauciflora individuals is likely to result in December 2000 disruption to the plant’s lifecycle by and the extent of occurrence is producing fewer opportunities for approximately 4.5km2. The area of outbreeding and thereby reducing the likely occupancy within this extent is much reproductive success of the species. smaller at just approximately 0.4km2. Regional distribution of habitat The loss of individuals from the limits of the plant’s distribution may result in a P. pauciflora habitat occurs in the range contraction, further isolation and Sydney Basin Bioregion. Patrick (1999) potentially a loss of genetic diversity. suggests that the species appears to be restricted to a single geology known as Adequacy of representation in the “Farley Formation”. This geology has conservation reserves a restricted occurrence in the North P. pauciflora has not been recorded from Rothbury - Branxton locality. any conservation reserves. The species is Limit of known distribution therefore inadequately conserved. P. pauciflora occurs over a restricted Critical habitat north-south range of approximately 4km. Critical habitat has not been declared for P. All sub-populations and individuals are pauciflora. located within 2.5km of the type locality For further information contact: Threatened Species Unit Central Directorate NSW NPWS PO Box 1967, Hurstville NSW 2220 Phone 02 9585 6678 www.npws.nsw.gov.au References Bernhardt, P. & Weston, P.H. (1996) The pollination ecology of Persoonia (Proteaceae) in eastern Australia.