Forest Vegetation types - Successional Development
Succession, as defined by Odum (1971), is an orderly process of community development that involves changes in species structure and community processes with time; it is reasonably directional and, therefore, predictable.
Successional development generally proceeds through a number of distinct stages (e.g. early, middle, late) that replace one another in a predictable sequence and which culminates in a relatively stable and self-perpetuating community condition called a climax. Climax communities are not static, but are subject to gradual long-term renewal, maintaining themselves (more or less) until stand-level disturbance causes a return to an earlier successional stage.
A climatic (or zonal) climax results when a forest community reflects regional climate norms and is not unduly affected by local extremes in site conditions. Although Nova Scotia is divided into nine climate-based ecoregions (Neily et al. 2005), for FEC purposes the province can be effectively represented by two ELC groups, referred to as Acadian and Maritime Boreal (See Forest Ecosystem Classification for Nova Scotia: Part III Ecosites (2010) for more details).
In the Acadian group, zonal climax forests are dominated by species such as hemlock, red spruce, sugar maple and beech. In the Maritime Boreal group, climax species include white spruce, balsam fir, red maple and white birch.
An edaphic climax results when a forest community cannot progress to the climatic climax due to local extremes in site conditions (e.g. low nutrient sites, dry sites, wet sites and floodplain sites). Species associated with these sites include black spruce, tamarack, red maple, pine and white ash.
Figures 3 to 7 summarize possible successional links between VTs in the Spruce Hemlock (SH), Spruce Pine (SP), Tolerant Hardwood (TH), Intolerant Hardwood (IH) and Mixedwood (MW) forest groups — the main forest groups found in the province.
Information contained in Figures 3 to 7 can be used to aid forest management planning; however, users are reminded that many variables can (and do) affect stand successional dynamics including: (i) the type and size of disturbance, (ii) the frequency and severity of disturbance, (iii) age class and structure at time of disturbance, (iv) presence / absence of advanced regeneration, and (iv) presence / absence of seed sources, etc. As a result, the successional links shown in Figures 3 to 7 should be considered a guide to what is possible, not a hard and fast rule or prescription.
Figure 3. Spruce Hemlock (SH) Forest Group — Successional Links
| Early | Middle | Late | |
| SH1 | IH3, IH4, IH6, MW4, MW5 | MW2, SH5, SH6, SH8 | MW3, SH1, SH2, SH3 |
| SH2 | IH4, IH6, MW4, MW5 | MW2, SH5, SH6, SH8 | SH1, SH2, SH3 |
| SH3 | IH3, IH4, IH5, IH6, MW4, MW5 | MW2, SH5, SH6, SH7, SH8 | SH1, SH2, SH3 |
| SH4 | IH1, IH2, IH4, IH6, MW4, MW5 | MW2, SH5, SH8, SH9 | SH4 |
| SH5 | IH3, IH4, IH5, IH6, MW4, MW5 | MW2, SH5, SH7, SH8 | MW1, MW3, SH1, SH2, SH3, SH4 |
| SH6 | IH3, IH4, IH5, IH6, MW4, MW5 | MW2, SH6, SH7, SH8 | MW1, MW3, SH1, SH2, SH3 |
| SH7 | IH3, IH4, IH5, IH6, MW4 | MW2, SH5, SH6, SH7, SH8 | MW1, MW3, SH3 |
| SH8 | IH3, IH4, IH5, IH6, MW5 | SH5, SH6, SH7, SH8, SH10 | MW1, MW3, SH1, SH2, SH3, SH4 |
| SH9 | IH4, IH6 | SH9, SP4 | SH4, SP5 |
| SH10 | IH4, IH6, MW4, MW5 | SH8, SH10, TH7 | MW1, MW3, TH8 |
Figure 4. Spruce Pine (SP) Forest Group — Successional Links
| Early | Middle | Late | |
| SP1 | SP1 | SP2, SP3, SP4 | SP5 |
| SP2 | SP1, SP2 | SP3, SP4 | SP5 |
| SP3 | SP1, SP2 | SP3, SP4 | SP5 |
| SP4 | SH9, SP1, SP2, SP8, SP9, SP10 | IH2, SP3, SP4, SP6 | SP5 |
| SP5 | SH9, SP1, SP2, SP8, SP10 | SP3, SP4, SP6 | SP5 |
| SP6 | IH1, SP8, SP10 | SP4, SP6 | SP5 |
| SP7 | SP7 | SP7 | SP7 |
| SP8 | SP8 | SP4, SP6 | SP5, SP9 |
| SP9 | IH1, SP8 | IH2, SP4 | SP9 |
| SP10 | SP10 | SP4, SP6 | SP5 |
Figure 5. Intolerant Hardwood (IH) Forest Group — Successional Links
| Early | Middle | Late | |
| IH1 | IH1, IH2 | SP6 | SH4, SP9 |
| IH2 | IH1, IH2 | SP4 | SH4, SP9 |
| IH3 | IH3, IH4, IH5, IH6 | IH7, MW2, SH5, SH6, SH7, SH8 | MW1, MW3, SH1, SH3, TH1, TH2, TH3, TH4, TH6, TH8 |
| IH4 | IH4 | IH7, MW2, MW4, SH5, SH6, SH7, SH8, SH9, SH10 | MW1, MW3, SH1, SH2, SH3, SH4, TH6, TH8 |
| IH5 | IH5, MW5 | IH7, MW4, SH5, SH6, SH7, SH8 | MW1, MW3, SH3, TH1, TH2, TH3, TH4, TH8 |
| IH6 | IH6 | IH7, MW2, SH5, SH6, SH7, SH8, SH9, SH10 | MW1, MW3, SH1, SH2, SH3, SH4, TH1, TH2, TH6, TH8 |
| IH7 | IH3, IH4, IH5, IH6 | IH7, TH7 | MW1, TH1, TH2, TH3, TH6, TH8 |
Figure 6. Tolerant Hardwood (TH) Forest Group — Successional Links
| Early | Middle | Late | |
| TH1 | IH3, IH5, IH6 | IH7, TH6, TH7 | TH1, TH8 |
| TH2 | IH3, IH5, IH6 | IH7, TH6, TH7 | TH2, TH8 |
| TH3 | IH3, IH5 | IH7 | TH3 |
| TH4 | IH3, IH5 | TH4 | |
| TH5 | IH7 | TH1, TH2, TH5 | |
| TH6 | IH3, IH4, IH6 | IH7 | TH1, TH2, TH6 |
| TH7 | MW4, MW5 | IH7, SH10, TH7 | MW1, MW3, TH1, TH2 |
| TH8 | IH3, IH4, IH5, IH6 | IH7, SH10 | TH1, TH2, TH8 |
Figure 7. Mixedwood (MW) Forest Group — Successional Links
| Early | Middle | Late | |
| MW1 | IH3, IH4, IH5, IH6, MW4, MW5, SH8 | IH7, MW2, SH5, SH6, SH7, SH10, TH7 | MW1, MW3 |
| MW2 | IH3, IH4, IH6, MW4, MW5 | MW2, SH5, SH6, SH7 | MW1, MW3, SH1, SH2, SH3, SH4 |
| MW3 | IH3, IH4, IH5, IH6, MW4, MW5, SH8 | MW2, SH5, SH6, SH7, SH10, TH7 | MW1, MW3, SH1 |
| MW4 | IH4, IH5 | MW2, MW4, SH5, SH6, SH7, SH10, TH7 | MW1, MW3, SH1, SH2, SH3, SH4 |
| MW5 | IH5, MW5 | MW2, SH5, SH6, SH8, SH10, TH7 | MW1, MW3, SH1, SH2, SH3, SH4 |
