Tropical cyclones are major disturbances for coastal systems. Hurricane Harvey made landfall in Texas, USA, on August 25, 2017 as a category 4 storm. There were two distinct disturbances associated with this storm that were spatially decoupled: (1) high winds causing direct damage and storm surge, and (2) high rains causing scouring floods and significant discharge of fresh water carrying carbon and nutrients to estuaries. Here, we provide a synthesis of the effects of Hurricane Harvey on biogeochemical, hydrographic, and biotic components of freshwater and estuarine systems and their comparative resistance and resilience to wind-and rain-driven disturbances. Wind-driven disturbances were most severe along the coastal barrier islands and lower estuaries, damaging mangroves and seagrass and increasing sediment coarseness. Rain-driven disturbances were most pronounced within freshwater streams and the upper estuaries. Large volumes of freshwater run-off reduced the abundance of riverine fauna and caused hypoxic and hyposaline conditions in the estuaries for over a week. In response to this freshwater input event, benthic fauna diversity and abundance decreased, but mobile fauna such as estuarine fishes did not markedly change. Although hydrographic and biogeochemical components were highly perturbed, they returned to baseline conditions within days. In contrast, biotic components demonstrated lower magnitude changes, but some of these organisms, particularly the sedentary flora and fauna, required weeks to months to return to pre-storm conditions, and some did not recover within the 6 months reported here. Our synthesis illustrates that resistance and resilience of system components may negatively co-vary and that structural components of coastal systems may be the most vulnerable to long-term changes following tropical cyclones.

1. Climate change is expected to alter rainfall and temperature regimes across the world. The hydrology and riparian zone vegetation of lotic ecosystems are tightly linked to rainfall and a mechanistic understanding of the effects of rainfall on lotic ecosystems is needed to forecast the ecological impacts of climate change.However, it is difficult to isolate rainfall effects from other environmental variables that covary across climates. To address this, we leveraged a unique steep rainfall gradient with few covarying changes in elevation, temperature, and geology to evaluate the effects of rainfall on stream invertebrate communities.2. We surveyed nine streams in the Texas Gulf Coast Prairie distributed along a 550-1,350 mm/year rainfall gradient. Four sites were classified as drier semiarid streams (<750 mm annual rainfall) and five sites were classified as wetter sub-humid streams (>750 mm annual rainfall). A suite of characteristics including benthic invertebrate community metrics, flow conditions, and water quality variables were assessed monthly for 14 months at each site to relate precipitation regime to stream structure and function.3. Precipitation regime was observed to be a master explanatory variable. As annual rainfall increased, the flow environment became more stable within seasons and predictable across seasons, influencing spatial structure and temporal variability of invertebrate community composition. Wetter streams were dominated by slower growing taxa without adaptions for desiccation resistance and strong dispersal. Wetter sites displayed seasonal variation in community composition and species richness, whereas temporal variation in communities in drier streams was controlled by stochastic variation in flow conditions. 4. These observations show that differences in local annual rainfall correlated with major changes to community structure and functional composition. We hypothesise that this association is related to the connection of rainfall to hydrological stability, particularly the frequency of low flow disturbances, and the

Anthropogenic climate change is expected to increase the aridity of many regions of the world. Surface water ecosystems are particularly vulnerable to changes in the water-cycle and may suffer adverse impacts in affected regions. To enhance our understanding of how freshwater communities will respond to predicted shifts in water-cycle dynamics, we employed a space for time approach along a natural precipitation gradient on the Texas Coastal Prairie. In the spring of 2017, we conducted surveys of 10 USGS-gauged, wadeable streams spanning a semi-arid to sub-humid rainfall gradient; we measured nutrients, water chemistry, habitat characteristics, benthic macroinvertebrates, and fish communities. Fish diversity correlated positively with precipitation and was negatively correlated with conductivity. Macroinvertebrate diversity peaked within the middle of the gradient. Semi-arid fish and invertebrate communities were dominated by euryhaline and live-bearing taxa. Sub-humid communities contained environmentally sensitive trichopterans and ephemeropterans as well as a variety of predatory fish which may impose top-down controls on primary consumers. These results warn that aridification coincides with the loss of competitive and environmentally sensitive taxa which could yield less desirable community states.

The cover image is based on the Original Article Structure and functional composition of macroinvertebrate communities in coastal plain streams across a precipitation gradient, by Fernando R. Carvallo et al. https://doi.org/10.1111/fwb.13968.