Scaling problem	Solution	Further reading
GENERAL
Focus on a single scale may obscure important processes that only become obvious at either finer or broader scales.	Ask questions about cumulative impacts on a broader scale than that being studied. Examine large-scale impacts on a smaller scale.	Schulze (2000)
TEMPORAL
Change within natural systems occurs at different rates.	Analysis should focus on the interactions between the slow and fast phenomena and monitoring should focus on long-term, slow changes in structural variables.	Holling (1993)
Process scales may be episodic (e.g., rainfall), cyclical (e.g., rainy season, long-term rainfall cycle), stochastic with a certain recurrence interval (e.g., a 1-in-10-year drought occurrence), ephemeral (e.g., stream flow) or continual (e.g., groundwater movement).	The observation scale at which samples are collected and phenomena are studied should match the scale at which the processes are taking place. Ideally, the process should be observed over a wide extent with high resolution and fine grain to allow any signal within the process to be observed at the appropriate time scale.	Bloschl and Sivapalan (1995), Jewitt and Gorgens (2000), Schulze (2000)
SPATIAL
Process scales exhibit spatial extent (e.g., the area over which the rainfall occurred), space period (e.g., the area over which a certain rainy season occurs), and correlation space (e.g., the area over which the 1-in-10-year drought left its mark).	As above, match the observation scales to the process scales.	Schulze (2000)
Dominant processes and physical laws change with scale.	Observations should be made at the scales at which the processes and physical laws are taking place.	Wood and Lakshmi (1993), Harvey (1997)
One process may dominate the response (e.g., rainfall distribution may dominate over land use or institutional performance).	Identify the dominant spatial forcing function of response and observe over a wide extent with high resolution and fine grain.	Bugmann (1997), Schulze (2000)
Elements in a natural system respond nonlinearly at different rates, according to different threshold scales and lags, and with varying degrees of feedback.	Isolate those significant elements that explain both the signal and the variance in the response.	Becker and Braun (1999), van Noordwijk et al. (2001)
INSTITUTIONAL
The assignment of jurisdiction over particular assets and functions across a spectrum of issues, which may range from local to global.	Strong local jurisdictions, affected by genuine devolution. Jurisdictions no larger than necessary (at levels where collective problem- solving makes most sense and has most autonomy). Aggregation through negotiated and reciprocal interest and interaction when ecological and functional scale imperatives require larger jurisdictional reach. Jurisdictional size matched to resource base. Constituent accountability. All this takes time and evolution.	Lee (1993), Williams (1998), Murphree (2000)
Jurisdictions imply boundaries, which may be spatial or resource-specific, overlapping or nested in larger systems.	Boundaries should be social, with specification of who has responsibility, who has authority, who has appropriative rights, and what the limits of these rights and responsibilities are.	Lee (1993), Williams (1998), Murphree (2000)
Two contrasting policy thrusts: “big government” (comprehensive authority located at a few nodes across the spectrum of expanding scale requirements) and “small is beautiful” (an approach that seeks to place jurisdictions at local or community levels).	Both are needed. Community-level ownership and decision making are fundamentally important, but community-level decisions should be made within a wider planning framework. The requirement is for local regime independence within the context of a larger, scalar interdependence.	Schumacher (1973), Adams (1990), Lee (1990), Ostrom (1990), Murphree (2000)