Conceptual domain of the matrix in fragmented landscapes
Summary (3 min read)
A matrix focus is now both important and possible
- The patch-matrix model of landscapes [20] includes patches that are useful for conservation and the matrix in which the patches are embedded [21] (see Glossary).
- Assumptions underpinning the patch-matrix model are reasonable in many situations, particularly in fragmented and relictual landscapes where there are patch-dependent species [22] [23] [24] .
- The growth in knowledge about the matrix means it is now possible to develop a detailed synthesis of the mechanisms by which the matrix directly, or indirectly drives the distribution of patch-dependent species in space and time.
- Habitat loss and fragmentation are the biggest threat to biodiversity globally [31] .
- There is now a pressing need for a comprehensive theoretical framework of the matrix to guide the way scientists and land managers think about matrix ecology.
Movement and Dispersal. Matrix quality influences the outcome of movement into the matrix
- Recent reviews report that movement between patches is enhanced as the matrix becomes structurally more similar to the remnant patches [40, 41] .
- The matrix can influence immigration and emigration in other ways.
- If a species does venture into the matrix, rapid movement through unfavourable habitat could enhance connectivity between separated habitat patches [42] .
- Red squirrel Tamiasciurus hudsonicus populations thrived on pine-seeds in Canadian pine plantations.
- With the possible exception of bees that can forage outside of the nesting patch [e.g. 14], evidence that patch-dependent species gather resources outside of the patch to support higher population densities inside the patch is limited [e.g. 46].
Abiotic environment. The matrix influences microclimate and disturbance regimes of patches.
- The physical structure of the matrix is often different from habitat patches and can alter the environmental conditions within patches [19, 37] , particularly when treed landscapes are cleared [25] .
- Changes to disturbance regimes in the matrix can also affect patch-dependent species.
- Larger and more frequent fires can occur if there are more ignitions in the matrix [11] , or when the fuel structure in the matrix is changed by forest logging [11, 49] or by invasive grasses [17] .
- Altered microclimate and disturbance regimes can advantage some species, often invasive exotic species [6, 17] , but disadvantage others, often species that depend on remnant vegetation [8] .
- Increased disturbance associated with urban or mining landscapes can also drive local extinctions in patches [9, 10] .
Spatial scale. The extent of the matrix influences its impacts on patch-dependent species
- The spatial scale of the matrix, including geographic extent and distance between patches (see Glossary), has an important effect on patch-dependent species.
- If patch-dependent species exploit resources in the matrix [34] , a proportionally greater area of matrix to patch could increase the relative abundance of such resources.
- Most edge studies disregard the scale of the adjacent matrix and so understanding of such effects is rudimentary.
- By examining the extent to which changes 9 in population size were synchronous, Powney et al. [58] found that matrix permeability to dispersal had the strongest effect on movement between patches at intermediate distances.
- Abiotic effects are highly dynamic [7] and change over time as a consequence of succession, seasonality, and changes in species composition, management and disturbance regimes.
Temporal scale. Demographic and dispersal rates influence responses to changes in the matrix
- In poorly dispersing lichen species, forest succession through plantation harvest cycles can be too rapid for colonisation, particularly when the matrix is extensive [70] .
- In contrast, where resources change gradually, dietary specialists can replace generalists as succession advances [73] .
- A species response to the matrix can change over time.
- As a research planning tool, it stimulates new ways of framing hypotheses about the matrix, including drawing attention to novel interactions among the dimensions and core effects (Box 5).
Figure 1. Matrix core effects
- The matrix can influence species abundance, community composition and ecological processes within patches of native vegetation through three core effects associated with (i) movement and dispersal, (ii) resources provided within the matrix, and (iii) the abiotic environment of patches.
- The matrix can also alter dispersal by acting as a barrier to emigration, or can promote dispersal leading to increased immigration.
- The matrix can provide resources that allow non-patch species to breed and subsequently spill over into patches.
- Each of these effects can have consequences for individual species, and subsequently for community composition (see Box 2 for a more detailed description of some pathways and Box 1 for consideration of species interactions).
- Numbers indicate studies listed in the references that support parts of each pathway.
Figure 2. Five dimensions modify matrix core effects
- The conceptual model of the matrix consists of the three core effects whereby the matrix influences patch-dependent species through effects associated with movement and dispersal, resource availability, and the abiotic environment.
- This does not imply any priortity of effects (although difficult to draw, these could also be imagined as overlapping spheres encompassing the core effects, like electrons around an atom's nucleus).the authors.
- The importance of patch characteristics and species interactions are well established (Boxes 1, 4).the authors.
- In another example, increasing resources in the matrix (seeds in wet years) enabled seed-eating rodents to forage widely throughout the landscape [84] .
- Competition-colonisation trade-offs or predator-prey patch dynamics [85] might also drive feedbacks between pathways in Figure 1 .
Box 2. New species colonise patches by multiple pathways
- By defining three core effects , their conceptual model puts colonisation of patches into a mechanistic context.
- Coffee plantations have received widespread attention as a matrix capable of supporting forest species [89] , but these plantations also provide resources for pest species.
- Such spill-over edge-effects could be more widespread than is currently recognised in the literature [56, 90] .
- Invasion changed the microclimate which reduced amphibian abundance and diversity [48] , along with effects on the invertebrate fauna [92] .
- Key responses to the changing matrix include: (i) new species were recruited to the landscape because the pine matrix provided breeding habitat ; (ii) a illremnants , and; (iii) a habitatwith measured temporal changes in vegetation attributes as the patches responded to the changed abiotic conditions and management regime.
Box 4. The patch still matters
- The matrix affects local populations through core effects associated with dispersal, the resource base and the abiotic environment, but patch dynamics are also strongly influenced by characteristics of the habitat patch itself.
- The rate of change of habitat quality within patches could allow, for example, long-lived species to readily survive short-term changes in habitat quality [99] .
- Patch size is often important, but spatial scale issues are more relevant when considering a matrix with multiple embedded patches.
Matrix
- The matrix is an extensive land-cover with different types of landcover embedded within it .
- The matrix does not provide for self-sustaining populations of some species, which are dependent upon the patches.
- The matrix therefore, includes the extensive landcover types that patch-dependent species cannot sustainably live in.
- This definition means that what is the matrix for some species, or was the matrix at one time, might not be at other times [15] or for other species [16] .
Did you find this useful? Give us your feedback
Citations
575 citations
385 citations
Cites background from "Conceptual domain of the matrix in ..."
...…dispersal, resource availability and abiotic environment) being modified by five dimensions: spatial and temporal variation in matrix quality, its spatial scale, the longevity and demographic rates of species relative to the temporal scale of matrix variation, and adaptation (Driscoll et al. 2013)....
[...]
319 citations
306 citations
216 citations
Cites background from "Conceptual domain of the matrix in ..."
...1c), improving landscape connectivity and resource availability for forest species (Dunning et al. 1992; Uezu et al. 2008; Asensio et al. 2009)....
[...]
References
4,266 citations
3,869 citations
3,715 citations
3,248 citations
3,195 citations
Related Papers (5)
Frequently Asked Questions (10)
Q2. What is the potential of research addressing these questions?
Research addressing these questions has the 272 potential to generate novel conservation strategies and improved understanding of ecological 273 phenomena in fragmented landscapes.
Q3. What are the key factors that contribute to making the matrix more or less hostile for patch-dependent?
Changes in the amount of tree 310 cover, the prevalence of exotic plant and animal species, fire regimes and land-use intensity 311 (among others) all contribute to making the matrix more or less hostile for patch-dependent 312 species.
Q4. What is the effect of a sharp ecotonal boundary between a patch and the matrix?
Sharp ecotonal 77 boundaries between a patch and the matrix can cause individuals to cluster inside remnants 78 ('fence effects') [1].
Q5. What are the main questions that have been asked about the 290 approaches to a matrix?
lists of possible 290 approaches have been proposed, such as maintaining a certain proportion of forest cover of 291 particular size [30], maintaining hedge-rows or reducing insecticide use [83].
Q6. What are the common responses of species to the matrix?
245 Plastic and evolutionary responses of species to the matrix are rarely considered, but have the 246 potential to influence response pathways.
Q7. What are the key changes that could make the conservation outlook more bleak?
These changes could make the conservation outlook more bleak as land use intensifies, 313 for example, but matrix changes also provide opportunities to support species in patches.
Q8. What might be the likely pathway to drive the feedbacks between pathways?
387 388 Competition-colonisation trade-offs or predator-prey patch dynamics [85] might also drive 389 feedbacks between pathways in Figure 1.
Q9. How many resources can be exploited by patch-dependent species?
If patch-dependent species exploit 167 resources in the matrix [34], a proportionally greater area of matrix to patch could increase the 168 relative abundance of such resources.
Q10. What is the likely effect of matrix heterogeneity on the spatial scale of a?
188 However, the effects of matrix heterogeneity are most likely to be apparent on the spatial scale of 189 individual movement behaviour [59] or the scale over which population synchrony occurs [58].