Sessile organisms, including plants and benthic macrofauna, are often restricted in the ranges over whichthey are able to reproduce and disperse. This leads to spatial patterning within populations, causing theeffective population density around each individual to depart from the average across its range. This hasimportant implications for population dynamics, in particular the minimum density at which populationsare able to maintain positive growth (the Allee threshold). Here we compare the population dynamics ofspecies with three syndromes — spatially restricted mating, dispersal or both — against a null model ofa species with no spatial limitations. First we demonstrate mathematically that the population densityat which Allee effects occur systematically shifts in each case. Next we use individual-based modelsrepresenting three exemplar species to simulate the implications for the Allee threshold of each withina fixed area. In the case where mating occurs over long ranges but dispersal is restricted (e.g. the wind-pollinated silver fir, Abies alba Mill.), there is a negligible impact on the Allee threshold. When mating isalso spatially restricted (e.g. the dipterocarp tree Shorea curtisii Dyer ex King), the Allee threshold reduces,unless high death rates prevent the stabilisation of aggregations. This occurs because offspring remainwithin the range of potential mating partners. Finally we consider a case in which mating is short-ranged,and dispersal effectively unrestricted, but in which individuals choose to locate themselves in the vicinityof conspecifics (e.g. acorn barnacles, Semibalanus balanoides). This has the effect of maintaining clusteringin the face of high dispersal, reducing the Allee threshold, and compensating for the apparent cost of short-range mating. Incorporating information on ranges of mating and dispersal can lead to more effectivemodels for the management of populations at low density, in particular the identification of species withsyndromes which make them vulnerable to Allee effects. Most notably, mechanisms which increase thedegree of clustering in populations increase both their resilience and persistence when finding a mate isthe greatest challenge faced by a sessile organism.