DRAFT
Monitoring of Erioderma pedicellatum at Lockyer’s Waters and Southeast Placentia Study Areas, Avalon Peninsula, Newfoundland: Spring 2007-Fall 2007
Prepared by:
Ian Goudie, Ph.D. and Eugene Conway
Newfoundland Lichen Education and Research Group
Box 16, Conception Hr., NL, A0A 1Z0
For:Voisey’s Bay Nickel Company Ltd.
10 Fort William Place
St. John’s, NL, A1C 1K4
January 1, 2008
The boreal felt lichen (Erioderma pedicellatum) is globally rare and considered an indicator of environmental quality. From fall of 2005 to fall of 2007, the Newfoundland Lichen Education and Research Group completed monitoring of the Boreal Felt Lichen (Erioderma pedicellatum) in the Lockyer’s Waters and Southeast Placentia study areas. It was apparent that recruitment was not sufficient to offset mortality. The results indicated that while juveniles were recruiting into the existing stands at a low rate (e.g. 0.039 of summer population), the rate of survival of these recruits was very low. The low frequency of casual detection of juveniles may, in part, be explained by this finding. The majority of mortality is occurring in the recruits or juvenile 1 class (26.3%) relative to the juvenile 2 class (7.0%) for Lockyer’s Waters. This supports that once juveniles (recruits) survive a six month period, their likelihood of survival increases considerably.
The population in Lockyer’s Waters was projected for another year, that is, fall 2006 to fall 2007. The growth rate (Lambda) was derived from the eigenvector as £ = 0.6629 indicating that the projected population there is declining at a rate of 0.3371 substantially more than the 0.0913 measured in 2005 to 2006. We noted that the decline was more dramatic in spring to fall 2007 (0.2307) than fall 2006 to spring 2007 (0.1539). This coincided with a cool wet summer.
Sensitivity analyses were performed to examine the relative influence of each cohort transition on the population growth rate (£). This supported that relative changes in the transition rates of thalli classed as necrotic loose and necrotic regenerating were by far the most important demographics influencing population viability of Erioderma pedicellatum in the Lockyer’s Waters study area. In general, balsam fir is not successfully regenerating in most parts of the study area due to excessive browsing by moose (Alces alces). We hypothesize that this is limiting habitat quality and availability for recruitment of the boreal felt lichen in the study areas.
Our findings confirm a continuing declining trend for the globally-rare Boreal Felt Lichen (Erioderma pedicellatum) in eastern Newfoundland as numbers in the relatively large sample at Lockyer’s Waters (n = 344) declined by approximately 13.9% over the summer period of spring to fall 2007. We confirmed a very low rate of juvenile recruitment was occurring in the monitored populations (e.g. ~3.6 % of the summer population in Lockyer’s Waters). The results did not corroborate the 2005 to 2006 findings that recruitment was lower, and mortality higher, in winter. The higher mortality registered in spring to summer 2007 (0.139) compared to winter 2006 to Spring 2007 (0.098) may have been related to the delayed spring and cool summer temperatures as adults demonstrated lower survival rates. Also both the winter (n = 13) and the summer (n = 13) intervals demonstrated identical recruitment in fall 2006 to fall 2007, in contrast to fall 2005 to fall 2006 when recruitment was much higher in summer (11 and 21, respectively). Nevertheless, it is now clear that the juvenile 1 class, hence the recruits, are the cohort most vulnerable to mortality.
The Boreal Felt Lichen population is declining rapidly at both study areas. The sample sizes for the Southeast Placentia area are small. Overall, these life stage data corroborated previous declines evident in data estimating numbers of thalli in Lockyer’s Waters in 1997, 2002, 2003 compared to 2005 (Goudie and Conway 2005), and more recently for 2005 to 2006 (Goudie and Conway 2007a). The preliminary population model presented here supported that the primary life cycle transitions influencing population growth (Lambda-£) were the survival of the necrotic-loose and necrotic regenerating cohorts. It is apparent that these cohorts may be relatively stable in that there is proportionately less transition to other life stages. However, an assessment of the stable age distribution indicates that fewer juvenile and adults, and more necrotic-loose and necrotic regenerating cohorts would be expected in the population if stabilized by these calculated demographic rates. An interpretation is that the population attained its current distribution of cohorts under a different set of demographic rates.
Population viability is being influenced least by juveniles, and these data continue to support that recruitment in the forest landscape may not be the issue limiting population viability in the Boreal Felt Lichen, and the population is sustained by longevity of adult thalli. These findings are consistent with the hypothesis that the single most important action promoting conservation is the retention of stands containing thalli (Sillett et al. 2000). This is an important finding for management and conservation of Erioderma pedicellatum because it suggests that identification and retention of “potential habitat” on the landscape may be of limited value if stands currently supporting this rare lichen are lost to commercial harvesting, fire, air pollution or other causes.
Sustainability of populations of the boreal felt lichen in the Avalon boreal forest maybe compromised by the lack of regenerating forests of balsam fir within areas where mature thalli occur. Currently, virtually all located juvenile and adult Erioderma pedicellatum occur on mostly over-mature balsam fir. In natural cycling stands we would expect balsam fir to be regenerating in the understory of over-mature stands as trees reach senescence and die. The prolific natural regeneration of balsam fir in the absence of moose creates a continuum of ‘wave forests’ within the existing stands of the boreal felt lichen, likely creating the microclimatic and substrate conditions for continued colonization and regeneration of this lichen within landscape units. In general, balsam fir is not successfully regenerating in most parts of the study area due to excessive browsing by moose (Alces alces). We hypothesize that this is limiting habitat quality and availability for recruitment of the boreal felt lichen in the study areas.
DRAFT
Erioderma pedicellatum Monitoring Report from November 2006- May 2007 at Lockyer’s Waters and Southeast Placentia Study Areas, Avalon Peninsula, Newfoundland
Prepared by:
Ian Goudie, Ph.D. and Eugene Conway
Newfoundland Lichen Education and Research Group
Box 16, Conception Hr., NL, A0A 1Z0
Voisey’s Bay Nickel Company Ltd.
10 Fort William Place
St. John’s, NL, A1C 1K4
October 15, 2007
Figure 2. Study area at Southeast Placentia, Avalon Peninsula, Newfoundland. 9
Appendix 1. Raw data for Erioderma pedicellatum in the Lockyer’s Waters study area, spring 2007. 19
The boreal felt lichen (Erioderma pedicellatum) is globally rare and considered an indicator of environmental quality. In fall of 2006, the Newfoundland Lichen Education and Research Group completed the first full year of monitoring of the Boreal Felt Lichen (Erioderma pedicellatum) in the Lockyer’s Waters and Southeast Placentia study areas. It was apparent that recruitment and growth were highest in summer. We confirmed a significant juvenile component in the monitored populations. The results indicated that while the juveniles are establishing within the existing stands, the rate of survival is very low, especially during winter. Commencing in 2007, we were able to discriminate the juvenile 1 and juvenile2 cohorts, and confirmed that the majority of mortality is occurring in the juvenile 1 class (26.3%) relative to the juvenile 2 class (7.0%) for Lockyer’s Waters where our sample sizes were sufficient. This supports that once juveniles survive a year, their likelihood of survival increases considerably.
A preliminary population model presented for Erioderma pedicellatum for fall 2005 to fall 2006 yielded the growth rate in Lockyer’s Waters was (Lamda) £ = 0.9087, and Southeast Placentia £ = 0.8334, indicating that those populations are declining at a rate of 0.0913 and 0.167 per year, respectively. The analyses of the demographic data for the fall 2006 to spring 2007 winter period are consistent with these findings, namely that recruitment is not sufficient to offset mortality in the forest landscape being studied, and populations demonstrated an overall mortality rate of 10% for the six-month period.
We re-confirmed the presence of two thalli considered to be Erioderma mollissimum in the Southeast Placentia study area of eastern Newfoundland.
The boreal felt lichen (Erioderma pedicellatum) is globally rare and considered an indicator of environmental quality (Maass and Yetman 2002). In 2005, the Newfoundland Lichen Education and Research Group through funding from Voisey’s Bay Nickel Inc. implemented a research protocol to monitor the Boreal Felt Lichen in the Lockyer’s Waters and Southeast Placentia study areas. Under the guidance of IUCN lichen expert Dr. Christoph Sheidegger, a methodology was refined in fall of 2005, repeated in spring 2006 and reported by Goudie and Conway (2006a, b). This report details the results collected in spring 2007, and hence represents aspects of demography that occurred over the intervening fall-spring period. These results complete half of the second full year of monitoring of demography of the Boreal Felt Lichen on the Avalon Peninsula of Newfoundland.
Populations declined significantly over the 2005-2006 winter period at >13.5% and >33.3%, for Lockyer’s Waters and Southeast Placentia, respectively (Goudie and Conway 2006b). Rates of declines varied markedly with cohorts, and it was evident that juvenile survival was extremely poor over the winter period in the Lockyer’s Waters study area whereas mortality was high across all cohorts at the Southeast Placentia study area. There was a low level of recruitment observed (<5%), and we were unsuccessful at locating new recruiting thalli in the general landscape area of our sites. Recruitment appeared to be occurring within existing forest stands supporting Erioderma pedicellatum , albeit at a relatively low level during the winter period.
This report details the second year of data and information arising from implementing a standardized scientific protocol to collect extensive data on the different life stages of the Boreal Felt Lichen in order to test hypotheses about the lifecycle of this species. It is critical to fully understand the life cycle and population dynamics of this lichen in the forest landscape in order to ascertain factors limiting its ability to sustain viable populations. These demographics are currently unknown for this rare lichen.
3. METHODS
The study areas (Figures 1 and 2) were resurveyed in spring 2006. Data previously collected included the:
(i) diameter breast height (dbh) of phorophytes,
(ii) site orientation of stands supporting Erioderma pedicellatum .,
(iii) cardinal orientation of thalli
(iv) forest types supporting phorophytes bearing Erioderma pedicellatum, namely:
(a) Balsam Fir-Pleurozium (bf-pl),
(b) Balsam Fir – Hylocomium (bf-hy)
(c) Balsam Fir-Clintonia (bf-cl),
(d) Balsam Fir-Spagnum (bf-sp),
(e) Black Spruce-Spagnum (bs-sp),
(f) Nemopanthus-Black Spruce-Kalmia (skn),
Note that the forest types listed are altered from the original presentation (after Meades and Moores 1989) by including Damman (1963). The types presented in Goudie and Conway (2006a) as Balsam Fir-Pleurozium-galium variant, bf-pl (ga), are now classed as Balsam Fir – Hylocomium (bf-hy).
(v) tree type, namely:
(a) semi-mature standing,
(b) mature standing,
(c) mature leaning,
(d) over-mature standing
(e) over-mature leaning,
(f) dead standing,
(g) dead leaning, and
(h) collapsed
(vi) rank of canopy cover, namely:
(a) 1: < 25%,
(b) 2: 25% – 50%,
(c) 3: 50% – 75%,
(d) 4: > 75%
This Boreal Felt Lichen Monitoring Study aims to collect morphometrics of thalli in order to assess growth and death rates of cohorts, as well as transition probabilities between the developmental stages of Erioderma pedicellatum, namely:
(i) juvenile1 (< 3mm),
(ii) juvenile2 (> 3 mm, no apothecia),
(iii) adults (healthy with apothecia, no necroses),
(iv) necrotic (thalli with necroses evident on thallus area),
(v) necrotic and loose
(vi) necrotic with regeneration, and
(vii) dying/dead.
In this the data reported here we were able to distinguish the juvenile1 and juvenile2 cohorts that were previously grouped for analyses (Goudie and Conway 2007). This was now possible because juveniles born within the intervening interval could be separated from those that were older. Note that the initial size categorization was somewhat arbitrary. It will now be possible to designate these classes, and they will be presented separately in modelling to be undertaken with the completion of the fall 2007 data collection.
Figure 1. Study area at Lockyer’s Waters, Avondale River watershed, Avalon Peninsula, Newfoundland. Figure 2. Study area at Southeast Placentia, Avalon Peninsula, Newfoundland.
Thalli are measured (horizontal maximum length and vertical maximum width in mm) using a handheld ruler, and season to season comparisons are the basis for assessments of growth rates of cohorts.
The degree of necrosis of a thallus is ranked as:
(i) 1: < 25%,
(ii) 2: 25% – 50%,
(iii) 3: 50% – 75%,
(iv) 4: > 75%
(v) 5: dead
The level of attachment of a thallus to the substrate was ranked as:
(i) 1: < 25%,
(ii) 2: 25% – 50%,
(iii) 3: 50% – 75%,
(iv) 4: > 75%
(v) 5: fully attached
Evidence of mite damage was ranked as:
a. 0 – none
b. 1 – mild
c. 2 – moderate
d. 3 – severe
In some cases the substrate was loose and we recorded this separately.
4. RESULTS 4.1 Lockyer’s Waters 4.1.1. Demography
In fall 2006, juveniles comprised 20.5% (72 of 351 thalli) of the detected population of Erioderma pedicellatum in the Lockyer’s Waters study area. The remaining adult population was predominated by thalli in various states of necrosis 61.5% (216 of 351 thalli) while healthy adults comprised 17.9% (63 of 351 thalli) of the population. In the intervening fall2006-spring2007 period, we documented a continued decrease (9.9 % or 31 of 314 thalli) in the population, and the mortality was predominantly in the juvenile1 class (26.3% (5 of 19 thalli). Commencing in 2007, we were able to discriminate the juvenile 1 and juvenile2 cohorts, and confirmed that the majority of mortality is occurring in the juvenile 1 class (26.3%) relative to the juvenile 2 class (7.0%) for Lockyer’s Waters.
There were 13 recruits observed (Table 1). Specific to phorophytes, 8.3% (22 of 266) phorophytes were recorded to have lost thalli (Table 2). Survival of mature thalli was relatively high with highest mortality occurring in the necrotic loose cohort (11.6% or 15 of 129 thalli). Consistent with the previous findings, the necrotic-loose cohort demonstrated the least transition into other cohorts (Table 3).
An additional 46 thalli were located on 31 phorophytes. All these were added to the data base for monitoring (Appendix 1).
Table 1. Numbers (proportions) by cohorts of thalli of Erioderma pedicellatum detected in fall 2006 and numbers relocated in spring 2007 in Lockyer’s Waters,
Year | Recruit | deceas | Juv1 | Juv2 | Adult | Necro | Necro loose | Necro Regen | Total |
Fall 2006 | 26 | 46 | 63 | 51 | 138 | 27 | 351 | ||
Spring 2007 | (13) | 31 | 19 | 43 | 53 | 45 | 129 | 25 | 314 |
Excluding deceased | 14 | 40 | 50 | 41 | 114 | 24 | 283 | ||
Not Surveyed | 7 | 3 | 10 | 6 | 9 | 2 | 37 |
Year | cohort | Juv1 | Juv2 | Adult | Necrotic | Necro loose | Necro Regen | Total |
Fall 2006 | alive | 19 | 43 | 53 | 45 | 129 | 25 | 314 |
Spring 2007 | deceased | 5 (0.263) | 3 (0.070) | 3 (0.057) | 4 (0.089) | 15 (0.116) | 1 (0.040) | 31 (0.099) |
Spring 2007 | ||||||||||
Cohort | Fall2006 | Juv1 | Juv2 | Adult | Necro | Necro loose | Necro regen | Deceas | Recruit | Not Surveyed1 |
Juv1 | 26 | 6 | 7 | 1 | 0 | 0 | 0 | 5 | (13) | 7 |
Juv2 | 46 | 0 | 14 | 14 | 7 | 3 | 2 | 3 | 3 | |
Adult | 63 | 0 | 0 | 25 | 12 | 11 | 2 | 3 | 10 | |
Necrotic | 51 | 0 | 0 | 5 | 17 | 17 | 3 | 4 | 5 | |
Nec-loos | 138 | 0 | 0 | 2 | 4 | 94 | 14 | 15 | 9 | |
Necregen | 27 | 0 | 1 | 2 | 2 | 4 | 15 | 1 | 2 | |
1 Some phorophytes were missed during surveys
4.2 Southeast Placentia 4.2.1. Demography
In spring 2007, juveniles comprised 5.5% (3 of 55) of the detected population of Erioderma pedicellatum in the Southeast Placentia study area. The remaining adult population was predominated by thalli in various states of necrosis (39 of 55 or 70.9%) while healthy adults comprised about 10.9% (6 of 55) of the population. We noted decreases in the proportion of adult and necrotic cohorts and while necrotic loose and necrotic regenerating cohorts decreased (Table 4). In the intervening winter period, 7 of 55 or 12.7% thalli deceased (Table 5) and, specific to phorophytes, 4 of 40 (10.0%) phorophytes were recorded to have lost thalli. Mortality occurred most in juveniles (1of 2 thalli or 50.0%), and necrotic-loose was the most abundant (Table 6). However sample sizes were small for this field site.
An additional 5 thalli were located on 3 phorophytes, and were added to the database for monitoring (Appendix 2).
Table 4. Numbers (proportions) by cohorts of thalli of Erioderma pedicellatum detected in fall 2006 and numbers relocated in spring 2007 in Southeast Placentia, eastern Newfoundland.
Year | Recruit | deceas | Juv1 | Juv2 | Adult | Necro | Nec_loos | Nec_Reg | Total |
Fall 2006 | 1 | 1 (0.018) | 2 (0.036) | 16 (0.291) | 7 (0.127) | 25 (0.455) | 4 (0.073) | 55 | |
Spring2007 | (2) | 7 | 0 (0.0) | 3 (0.055) | 6 (0.109) | 3 (0.055) | 30 (0.546) | 6 (0.109) | 55 |
Excluding deceased | 0 (0.0) | 0.063 | 0.125 | 0.063 | 0.625 | 0.125 | 48 | ||
Table 5. Numbers (proportions) of thalli by cohorts of Erioderma pedicellatum registered as deceased in fall 2007 in Southeast Placentia, eastern Newfoundland.
Year | cohort | Juv1 | Juv2 | Adult | Necrotic | Necro loose | Necro Regen | Total |
Fall 2006 | alive | 1 | 2 | 16 | 7 | 25 | 4 | 55 |
Spring 2007 | deceased | 0 (0.00) | 1 (0.50) | 2 (0.125) | 1 (0.143) | 2 (0.080) | 1 (0.25) | 7 (0.127) |
Table 6. Cohort transition matrix for Erioderma pedicellatum at Southeast Placentia, eastern Newfoundland from fall 2006 to spring 2007.
Cohort Spring 2007 | |||||||||
Cohort | Fall2006 | Juv1 | Juv2 | Adult | Necro | Necro loose | Necro regen | Deceas | Recruit |
Juv1 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | (2) |
Juv2 | 2 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 |
Adult | 16 | 0 | 0 | 6 | 1 | 7 | 0 | 2 | 0 |
Necrotic | 7 | 0 | 0 | 0 | 2 | 4 | 0 | 1 | 0 |
Nec-loos | 25 | 0 | 1 | 0 | 19 | 3 | 2 | 0 | |
Nec-regen | 4 | 0 | 0 | 0 | 0 | 3 | 1 | 0 | |
Our findings confirm a continuing declining trend for the globally-rare Boreal Felt Lichen (Erioderma pedicellatum) in eastern Newfoundland as numbers in the relatively large sample at Lockyer’s Waters declined by approximately 10% over the winter period. We further confirmed juvenile recruitment was occurring in the monitored populations (e.g. ~3.6 % of the spring population in Lockyer’s Waters). The results further supported that recruitment was lower, and mortality higher, in winter.
The Boreal Felt Lichen population is declining rapidly at both study areas although more precipitously in the Southeast Placentia study area. The sample sizes for the latter are small. This corroborates previous declines evident in data estimating numbers of thalli in Lockyer’s Waters in 1997, 2002, 2003 compared to 2005 (Goudie and Conway 2005). The preliminary population model presented by Goudie and Conway (2007) supported that the primary factor influencing population growth (Lambda-£) is the survival of the necrotic-loose cohort, and this was independently the case for both the Lockyer’s Waters and Southeast Placentia study areas. It is apparent that this cohort is the most numerous, and it is relatively stable in that there is proportionately less transition to other classes. Population viability is not being influenced by juveniles, and these data supported that recruitment in the forest landscape may not be the issue limiting population viability in the Boreal Felt Lichen, and the population is sustained by longevity of adult thalli. This supports that the single most important action promoting conservation is the retention of stands containing thalli (Sillett et al. 2000). This is an important finding for management and conservation of Erioderma pedicellatum because it suggests that identification and retention of “potential habitat” on the landscape may be of limited value if stands currently supporting this rare lichen are lost to commercial harvesting, fire, air pollution or other causes.
Balsam fir is not successfully regenerating in most parts of the study area due to excessive browsing by moose (Alces alces). This may be limiting habitat quality and availability for recruitment of the boreal felt lichen in the study areas.
Goudie, R. I., and Conway, E. 2005. Status of Eriodema pedicellatum at Lockyer’s Waters -Avondale, Newfoundland during 1997, 2002, 2003 & 2005. Report to Voisey’s Bay Nickel Company Ltd. by Newfoundland Lichen Education and Research Group, P.O. Box 16, Conception Hr., NL, A0A 1Z0.
Goudie, R. I., and Conway, E. 2007. First Annual Report of Monitoring of Erioderma pedicellatum at Lockyer’s Waters and Southeast Placentia Study Areas, Avalon Peninsula, Newfoundland: Fall 2006. Report to Voisey’s Bay Nickel Company Ltd. by Newfoundland Lichen Education and Research Group, P.O. Box 16, Conception Hr., NL, A0A 1Z0.
Maass, W. S. G., and D. Yetman. 2002. COSEWIC assessment and status report on the boreal felt lichen Erioderma pedicellatum in Canada. Committee On the Status of Endangered Wildlife In Canada. Environment Canada, Ottawa. 50pp.
Sillett, S. C., B. McCune, J. E. Peck, T. R. Rambo, and A. Ruchty. 2000. Dispersal limitations of epiphytic lichens result in species dependent on old-growth forests. Ecological Applications 10(3): 789-799.